NilsML/retriever_dataset · Datasets at Hugging Face

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Circadian rhythms and migration are examples of which behaviors?	regular	periodic	natural	cyclic	Types of animal behavior include cyclic behaviors such as circadian rhythms and migration.
Acids are classified based on their what?	diffusion in water	solvency	reaction to gas	ionization in water	Acids are classified as either strong or weak, based on their ionization in water. A strong acid is an acid which is completely ionized in an aqueous solution. Hydrogen chloride (HCl) ionizes completely into hydrogen ions and chloride ions in water.
What type of muscle enables the body to move?	Sartorius	Latissimus Dorsi	gluteus maximus	skeletal muscle	Human Skeletal Muscles. Skeletal muscles enable the body to move.
What results when volcanic ash encircles the globe, blocking the sun and lowering the temperature of the entire planet?	seismic winter	volcanic freeze	seismic apocalypse	volcanic winter	Supervolcanoes are the most dangerous type of volcano. During an eruption, enormous amounts of ash are thrown into the atmosphere. The ash encircles the globe. This blocks the Sun and lowers the temperature of the entire planet. The result is a volcanic winter.
Oxygen and glucose are both reactants in the process of	death	reproduction	birth	cellular respiration	Oxygen and glucose are both reactants in the process of cellular respiration.
Why does the moon evolve around the earth rather than the sun?	stronger magnetic force	stronger planetary force	weaker gravitational force	stronger gravitational force	Objects that are closer together have a stronger force of gravity. For example, the moon is closer to Earth than it is to the more massive sun, so the force of gravity is greater between the moon and Earth than between the moon and the sun. That’s why the moon circles around Earth rather than the sun. This is illustrated in Figure below .
What is an area in a body of water where nothing grows because there is too little oxygen known as?	deceased zone	missing zone	cold zone	dead zone	Rain dissolves fertilizer in the soil. Runoff carries it away. The fertilizer ends up in bodies of water, from ponds to oceans. The nitrogen is a fertilizer in the water bodies. Since there is a lot of nitrogen it causes algae to grow out of control. Figure below shows a pond covered with algae. Algae may use up so much oxygen in the water that nothing else can grow. Soon, even the algae die out. Decomposers break down the dead tissue and use up all the oxygen in the water. This creates a dead zone. A dead zone is an area in a body of water where nothing grows because there is too little oxygen. There is a large dead zone in the Gulf of Mexico. You can see it Figure below .
Most air pollutants can be traced to what source ?	ozone leaks	methane	chemical pollution	fossil fuels	Most air pollutants can be traced to the burning of fossil fuels. Fossil fuels are burned during many processes, including in power plants to create electricity, in factories to make machinery run, in power stoves and furnaces for heating, and in waste facilities. Perhaps one of the biggest uses of fossil fuels is in transportation. Fossil fuels are used in cars, trains, and planes.
A species become separated and becomes two separate species. what can they not do anymore?	eat	grow	defecate	breed	Assume that some members of a species become geographically separated from the rest of the species. If they remain separated long enough, they may evolve genetic differences. If the differences prevent them from interbreeding with members of the original species, they have evolved into a new species. Speciation that occurs in this way is called allopatric speciation . An example is described in Figure below .
A phase diagram plots pressure and what else?	precipitation	oxygen	volume	temperature	Summary The states of matter exhibited by a substance under different temperatures and pressures can be summarized graphically in a phase diagram, which is a plot of pressure versus temperature. Phase diagrams contain discrete regions corresponding to the solid, liquid, and gas phases. The solid and liquid regions are separated by the melting curve of the substance, and the liquid and gas regions are separated by its vapor pressure curve, which ends at the critical point. Within a given region, only a single phase is stable, but along the lines that separate the regions, two phases are in equilibrium at a given temperature and pressure. The lines separating the three phases intersect at a single point, the triple point, which is the only combination of temperature and pressure at which all three phases can coexist in equilibrium. Water has an unusual phase diagram: its melting point decreases with increasing pressure because ice is less dense than liquid water. The phase diagram of carbon dioxide shows that liquid carbon dioxide cannot exist at atmospheric pressure. Consequently, solid carbon dioxide sublimes directly to a gas.
What occurs when the immune system reacts to substances in food as though they were harmful “foreign invaders"?	vomiting	food poisoning	food antibodies	food allergies	Food allergies occur when the immune system reacts to substances in food as though they were harmful “foreign invaders. ” Foods that are most likely to cause allergies are pictured in Figure below . Symptoms of food allergies often include vomiting and diarrhea.
Recycling items actually takes more energy than what other conservation methods that start with "r"?	reusing and reordering	reducing and regurgitating	revision and remembrance	reducing and reusing	We haven’t done as well with the first two “R”s — reducing and reusing. But they aren’t always as easy as recycling. Recycling is better than making things from brand new materials. But it still takes some resources to turn recycled items into new ones. It takes no resources at all to reuse items or not buy them in the first place.
What science studies chemical processes that are found in living things?	psysiology	physiology	marine biology	biochemistry	Biochemistry is the study of chemical processes in living systems. In this chapter, we will explore some of the basic chemical components of biological systems and develop an understanding of the roles played by each major type of biomolecule.
Nonmetals typically lack what capability, because they hold onto their electrons?	mental capacity	magnetic attraction	repelling electricity	conducting electricity	Like most other nonmetals, fluorine cannot conduct electricity, and its electrons explain this as well. An electric current is a flow of electrons. Elements that readily give up electrons (the metals) can carry electric current because their electrons can flow freely. Elements that gain electrons instead of giving them up cannot carry electric current. They hold onto their electrons so they cannot flow.
What is the process called in which populations of organisms change over time?	mutation	generation	emergence	evolution	Evolution is the process by which populations of organisms change over time. It is a process that began on this planet well over 3.5 billion years ago and continues to this day, as populations of organisms continue to change.
An environment reaches its carrying capacity when the number of individual births in it equal the number of what else?	homes	infections	insects	deaths	The carrying capacity of an environment is reached when the number of births equal the number of deaths.
Pulmonary and systemic circulation loops are part of what organ system?	nervous	lymphatic	circulatory	cardiovascular	Compare and contrast the pulmonary and systemic circulation loops of the cardiovascular system.
What are materials that cannot conduct thermal energy efficiently known as?	atmospheric insulators	convection insulators	physical insulators	thermal insulators	Materials that are poor conductors of thermal energy are called thermal insulators. Gases such as air and materials such as plastic and wood are thermal insulators.
The temporomandibular joint (tmj) is the joint that allows for opening (mandibular depression) and closing (mandibular elevation) of this?	eyes	ears	nose	mouth	Temporomandibular Joint The temporomandibular joint (TMJ) is the joint that allows for opening (mandibular depression) and closing (mandibular elevation) of the mouth, as well as side-to-side and protraction/retraction motions of the lower jaw. This joint involves the articulation between the mandibular fossa and articular tubercle of the temporal bone, with the condyle (head) of the mandible. Located between these bony structures, filling the gap between the skull and mandible, is a flexible articular disc (Figure 9.15). This disc serves to smooth the movements between the temporal bone and mandibular condyle. Movement at the TMJ during opening and closing of the mouth involves both gliding and hinge motions of the mandible. With the mouth closed, the mandibular condyle and articular disc are located within the mandibular fossa of the temporal bone. During opening of the mouth, the mandible hinges downward and at the same time is pulled anteriorly, causing both the condyle and the articular disc to glide forward from the mandibular fossa onto the downward projecting articular tubercle. The net result is a forward and downward motion of the condyle and mandibular depression. The temporomandibular joint is supported by an extrinsic ligament that anchors the mandible to the skull. This ligament spans the distance between the base of the skull and the lingula on the medial side of the mandibular ramus. Dislocation of the TMJ may occur when opening the mouth too wide (such as when taking a large bite) or following a blow to the jaw, resulting in the mandibular condyle moving beyond (anterior to) the articular tubercle. In this case, the individual would not be able to close his or her mouth. Temporomandibular joint disorder is a painful condition that may arise due to arthritis, wearing of the articular cartilage covering the bony surfaces of the joint, muscle fatigue from overuse or grinding of the teeth, damage to the articular disc within the joint, or jaw injury. Temporomandibular joint disorders can also cause headache, difficulty chewing, or even the inability to move the jaw (lock jaw). Pharmacologic agents for pain or other therapies, including bite guards, are used as treatments.
What gas consisting of three oxygen atoms is found largely in the stratosphere?	smog	carbon	greenhouse	ozone	Air also includes water vapor. The amount of water vapor varies from place to place. That’s why water vapor isn’t included in Figure above . It can make up as much as 4 percent of the air. Ozone is a molecule made of three oxygen atoms. Ozone collects in a layer in the stratosphere.
Esters can be formed by heating carboxylic acids and alcohols in the presence of?	an oxygen catalyst	a nuclear catalyst	an carbon catalyst	an acid catalyst	Esters can be formed by heating carboxylic acids and alcohols in the presence of an acid catalyst. This process is reversible, and the starting materials can be regenerated by reacting an ester with water in the presence of a weak base.
Glucose that remains in the filtrate of what organ is excreted?	liver	spleen	intestine	kidney	null
What part of a plant helps it reproduce by being ejected from flowers and fruits?	roots	berries	cells	seeds	null
Energy contents of foods are often expressed in what?	nutrients	pulses	grams	calories	One area where the calorie is used is in nutrition. Energy contents of foods are often expressed in calories. However, the calorie unit used for foods is actually the kilocalorie (kcal). Most foods indicate this by spelling the word with a capital C—Calorie. Figure 7.1 "Calories on Food Labels" shows one example. So be careful counting calories when you eat!.
The plasma membranes of cells that specialize in absorption are folded into fingerlike projections called what?	flagella	digits	epithelial	microvilli	The plasma membranes of cells that specialize in absorption are folded into fingerlike projections called microvilli (singular = microvillus); ( Figure 4.10). Such cells are typically found lining the small intestine, the organ that absorbs nutrients from digested food. This is an excellent example of form following function. People with celiac disease have an immune response to gluten, which is a protein found in wheat, barley, and rye. The immune response damages microvilli, and thus, afflicted individuals cannot absorb nutrients. This leads to malnutrition, cramping, and diarrhea. Patients suffering from celiac disease must follow a gluten-free diet.
Sweating and panting are methods mammals use for what purpose?	staying alert	sleeping	staying warm	staying cool	Mammals also have several ways to stay cool, including sweating or panting.
A closed loop through which a current can flow is called what?	powered circuit	charged circuit	cooling circuit	electric circuit	A closed loop through which current can flow is called an electric circuit . In homes in the U. S. , most electric circuits have a voltage of 120 volts. The amount of current (amps) a circuit carries depends on the number and power of electrical devices connected to the circuit. Home circuits generally have a safe upper limit of about 20 or 30 amps.
Unsaturated hydrocarbons with at least one triple bond are known as?	aromatic hydrocarbons	benzenes	alkenes	alkynes	Unsaturated hydrocarbons that contain at least one triple bond are called alkynes . The name of specific alkynes always end in – yne , with a prefix for the number of carbon atoms. Figure below shows the smallest alkyne, called ethyne, which has just two carbon atoms. Ethyne is also called acetylene. It is burned in acetylene torches, like the one in Figure below . Acetylene produces so much heat when it burns that it can melt metal. Breaking all those bonds between carbon atoms releases a lot of energy.
What two types of organism make up a lichen?	snakes and bacteria	insects and bacteria	animals and viruses	fungus and bacteria	Have you ever seen an organism called a lichen? Lichens are crusty, hard growths that you might find on trees, logs, walls, and rocks ( Figure below ). Although lichens may not be the prettiest organisms in nature, they are unique. A lichen is really two organisms, sometimes referred to as a composite organism, that live very closely together: a fungus and a bacterium or an alga. The cells from the alga or bacterium live inside the fungus. Besides providing a home, the fungus also provides nutrients. In turn, the bacterium or the alga provides energy to the fungus by performing photosynthesis, obtaining energy directly from the sun. A lichen is also an example of a mutualistic relationship. Because lichens can grow on rocks, these organisms are some of the earliest life forms in new ecosystems.
The cell regulates most molecules that pass through what cell structure?	protective wall	plasma	ribosome	cell membrane	The cell regulates most molecules that pass through the cell membrane. If a molecule is charged or very big, it won't make it through the cell membrane on its own. However, small, non-charged molecules like oxygen, carbon dioxide, and water, can pass through the cell membrane freely.
What are groups of skeletal muscle fibers wrapped in?	tendons	neurons	collagen	connective tissue	Each skeletal muscle consists of hundreds or even thousands of skeletal muscle fibers . The fibers are bundled together and wrapped in connective tissue, as shown Figure below . The connective tissue supports and protects the delicate muscle cells and allows them to withstand the forces of contraction. It also provides pathways for nerves and blood vessels to reach the muscles. Skeletal muscles work hard to move body parts. They need a rich blood supply to provide them with nutrients and oxygen and to carry away their wastes.
Density is considered what type of property, because it does not depend on the amount of material present in the sample?	exensive property	independent variable	experimental property	intensive property	Density is an intensive property, meaning that it does not depend on the amount of material present in the sample. Water has a density of 1.0 g/mL. That density is the same whether you have a small glass of water or a swimming pool full of water. Density is a property that is constant for the particular identity of the matter being studied.
Prior to binding to a hormone, where are steroid hormone receptors located?	hypothalamus	cortisol	reticulum	cytosol	null
Which scale measures acids and bases and has 7 as a neutral value?	respiration	rock	color	ph	The Concept of pH The relative acidity or alkalinity of a solution can be indicated by its pH. A solution’s pH is the negative, base-10 logarithm of the hydrogen ion (H+) concentration of the solution. As an example, a pH 4 solution has an H+ concentration that is ten times greater than that of a pH 5 solution. That is, a solution with a pH of 4 is ten times more acidic than a solution with a pH of 5. The concept of pH will begin to make more sense when you study the pH scale, like that shown in Figure 2.17. The scale consists of a series of increments ranging from 0 to 14. A solution with a pH of 7 is considered neutral—neither acidic nor basic. Pure water has a pH of 7. The lower the number below 7, the more acidic the solution, or the greater the concentration of H+. The concentration of hydrogen ions at each pH value is 10 times different than the next pH. For instance, a pH value of 4 corresponds to a proton concentration of 10–4 M, or 0.0001M, while a pH value of 5 corresponds to a proton concentration of 10–5 M, or 0.00001M. The higher the number above 7, the more basic (alkaline) the solution, or the lower the concentration of H+. Human urine, for example, is ten times more acidic than pure water, and HCl is 10,000,000 times more acidic than water.
What do we call people who are trained to make specific dietary recommendations to address particular issues relating to health?	pulmonologists	clinicians	geologists	dietitians	Career Focus: Dietitian A dietitian is a nutrition expert who communicates food-related information to the general public. In doing so, dietitians promote the general well-being among the population and help individuals recover from nutritionally related illnesses. Our diet does not just supply us with energy. We also get vitamins, minerals, and even water from what we eat. Eating too much, too little, or not enough of the right foods can lead to a variety of problems. Dietitians are trained to make specific dietary recommendations to address particular issues relating to health. For example, a dietitian might work with a person to develop an overall diet that would help that person lose weight or control diabetes. Hospitals employ dietitians in planning menus for patients, and many dietitians work with community organizations to improve the eating habits of large groups of people.
An artery is a blood vessel that conducts blood away from the what?	lung	stomach	brain	heart	Arteries An artery is a blood vessel that conducts blood away from the heart. All arteries have relatively thick walls that can withstand the high pressure of blood ejected from the heart. However, those close to the heart have the thickest walls, containing a high percentage of elastic fibers in all three of their tunics. This type of artery is known as an elastic artery (Figure 20.4). Vessels larger than 10 mm in diameter are typically elastic. Their abundant elastic fibers allow them to expand, as blood pumped from the ventricles passes through them, and then to recoil after the surge has passed. If artery walls were rigid and unable to expand and recoil, their resistance to blood flow would greatly increase and blood pressure would rise to even higher levels, which would in turn require the heart to pump harder to increase the volume of blood expelled by each pump (the stroke volume) and maintain adequate pressure and flow. Artery walls would have to become even thicker in response to this increased pressure. The elastic recoil of the vascular wall helps to maintain the pressure gradient that drives the blood through the arterial system. An elastic artery is also known as a conducting artery, because the large diameter of the lumen enables it to accept a large volume of blood from the heart and conduct it to smaller branches.
The small amount of energy input necessary for all chemical reactions to occur is called what?	decomposition energy	nuclear energy	distinct energy	activation energy	Activation Energy There is another important concept that must be considered regarding endergonic and exergonic reactions. Even exergonic reactions require a small amount of energy input to get going before they can proceed with their energy-releasing steps. These reactions have a net release of energy, but still require some energy in the beginning. This small amount of energy input necessary for all chemical reactions to occur is called the activation energy (or free energy of activation) and is abbreviated EA (Figure 6.10). Why would an energy-releasing, negative ∆G reaction actually require some energy to proceed? The reason lies in the steps that take place during a chemical reaction. During chemical reactions, certain chemical bonds are broken and new ones are formed. For example, when a glucose molecule is broken down, bonds between the carbon atoms of the molecule are broken. Since these are energy-storing bonds, they release energy when broken. However, to get them into a state that allows the bonds to break, the molecule must be somewhat contorted. A small energy input is required to achieve this contorted state. This contorted state is called the transition state, and it is a high-energy, unstable state. For this reason, reactant molecules don’t last long in their transition state, but very quickly proceed to the next steps of the chemical reaction. Free energy diagrams illustrate the energy profiles for a given reaction. Whether the reaction is exergonic or endergonic determines whether the products in the diagram will exist at a lower or higher energy state than both the reactants and the products. However, regardless of this measure, the transition state of the reaction exists at a higher energy state than the reactants, and thus, EA is always positive.
What linear polymer of glucose units is found in plants and serves a structural purpose?	sucrose	frucose	carbonate	cellulose	Cellulose is a structural polymer of glucose units found in plants. It is a linear polymer with the glucose units linked through β-1,4-glycosidic bonds.
When the temperature of water is increased after being used in cooling, it is this form of pollution?	air	atmospheric	cosmic	thermal	Thermal pollution is pollution that raises the temperature of water. This is caused by power plants and factories that use the water to cool their machines. The plants pump cold water from a lake or coastal area through giant cooling towers, like those in Figure below . As it flows through the towers, the cold water absorbs heat. This warmed water is returned to the lake or sea. Thermal pollution can kill fish and other water life. It's not just the warm temperature that kills them. Warm water can’t hold as much oxygen as cool water. If the water gets too warm, there may not be enough oxygen for living things.
Which biological system is responsible for getting rid of chemical waste and water?	digestive system	endocrine system	mucous system	urinary system	null
What part of the body protects the brain?	lungs	feet	arms	cranium (skull)	The cranium (skull) to protect the brain. The brain is attached to the spinal cord.
Ammonium nitrate and ammonium sulfate are used in fertilizers as a source of what?	biofuel	bacteria	oxygen	nitrogen	Ammonium nitrate and ammonium sulfate are used in fertilizers as a source of nitrogen. The ammonium cation is tetrahedral. Refer to Section 2.1 "Chemical Compounds" to draw the structure of the ammonium ion.
What kind of light bulb has a tungsten filament?	sodium	fluorescent	translucent	incandescent	An incandescent light bulb like the one pictured in the Figure below produces visible light by incandescence. Incandescence occurs when something gets so hot that it glows. An incandescent light bulb contains a thin wire filament made of tungsten. When electric current passes through the filament, it gets extremely hot and emits light.
What is the name for the circle that runs north to south and passes through greenwich, england?	equator	odd meridian	time zone	prime meridian	Lines of longitude are circles that go around Earth from pole to pole, like the sections of an orange. Longitude is also measured in degrees, which are subdivided into minutes and seconds. Lines of longitude start at the Prime Meridian, which is 0°. The Prime Meridian is a circle that runs north to south and passes through Greenwich, England. Longitude tells you how far you are east or west from the Prime Meridian ( Figure below ). On the opposite side of the planet from the Prime Meridian is the International Date Line. It is at 180°. This is the place where a new day first arrives.
What map coordinates correspond to similar climate zones and life zones?	latitude and longitude	equator and poles	the poles	altitude and latitude	Altitude and latitude produce similar climate zones and life zones.
In myasthenia gravis, antibodies bind to and block certain receptors on muscle cells, preventing what?	muscle buildup	muscle layer	muscle diffusion	muscle contraction	null
What helps cells reduce their reaction to excessive hormone levels?	evaporation	apoptosis	adhesion	downregulation	Factors Affecting Target Cell Response You will recall that target cells must have receptors specific to a given hormone if that hormone is to trigger a response. But several other factors influence the target cell response. For example, the presence of a significant level of a hormone circulating in the bloodstream can cause its target cells to decrease their number of receptors for that hormone. This process is called downregulation, and it allows cells to become less reactive to the excessive hormone levels. When the level of a hormone is chronically reduced, target cells engage in upregulation to increase their number of receptors. This process allows cells to be more sensitive to the hormone that is present. Cells can also alter the sensitivity of the receptors themselves to various hormones. Two or more hormones can interact to affect the response of cells in a variety of ways. The three most common types of interaction are as follows: • The permissive effect, in which the presence of one hormone enables another hormone to act. For example, thyroid hormones have complex permissive relationships with certain reproductive hormones. A dietary deficiency of iodine, a component of thyroid hormones, can therefore affect reproductive system development and functioning. • The synergistic effect, in which two hormones with similar effects produce an amplified response. In some cases, two hormones are required for an adequate response. For example, two different reproductive hormones—FSH from the pituitary gland and estrogens from the ovaries—are required for the maturation of female ova (egg cells). • The antagonistic effect, in which two hormones have opposing effects. A familiar example is the effect of two pancreatic hormones, insulin and glucagon. Insulin increases the liver’s storage of glucose as glycogen, decreasing blood glucose, whereas glucagon stimulates the breakdown of glycogen stores, increasing blood glucose.
Smog is an example of the formation of what kind of pollutant, which occurs when primary pollutants undergo chemical reactions after they are released?	primary pollutant	combined pollutant	tertiary pollutant	secondary pollutant	Primary pollutants enter the air directly. They include carbon, nitrogen, and sulfur oxides. Toxic heavy metals, VOCs, and particulates are also primary pollutants. Secondary pollutants form when primary pollutants undergo chemical reactions after they are released. Many occur as part of photochemical smog. The main component of smog is ozone.
What occurs when a sperm and an egg fuse?	infection	migration	pollination	fertilization	Many animals have a relatively simple life cycle. A general animal life cycle is shown in Figure below . Most animals spend the majority of their life as diploid organisms. Just about all animals reproduce sexually. Diploid adults undergo meiosis to produce haploid sperm or eggs. Fertilization occurs when a sperm and an egg fuse. The diploid zygote that forms develops into an embryo. The embryo eventually develops into an adult, often going through one or more larval stages on the way. A larva (larvae, plural) is a distinct juvenile form that many animals go through before becoming an adult. The larval form may be very different from the adult form. For example, a caterpillar is the larval form of an insect that becomes a butterfly as an adult.
How many bases does dna have in total?	six	three	twelve	four	Every DNA and RNA polymer consists of multiple nucleotides strung together into extremely long chains. The only variation in each nucleotide is the identity of the nitrogenous base. The figure above shows one example of a nitrogenous base, called adenine. There are only five different nitrogenous bases found in all nucleic acids. The four bases of DNA are adenine, thymine, cytosine, and guanine, abbreviated A, T, C, and G respectively. In RNA, the base thymine is not found and is instead replaced by a different base called uracil, abbreviated U. The other three bases are present in both DNA and RNA.
Compound machines tend to have a greater mechanical advantage than what other machines?	digital machines	levers	magnets	simple machines	The mechanical advantage of a machine is the factor by which it changes the force applied to the machine. Many machines increase the force applied to them, and this is how they make work easier. Compound machines tend to have a greater mechanical advantage than simple machines. That’s because the mechanical advantage of a compound machine equals the product of the mechanical advantages of all its component simple machines. The greater the number of simple machines it contains, the greater its mechanical advantage tends to be.
Name the missing type of light: ultraviolet, infrared, ___________.	distinct	vertical	predictable	visible	Between these two extremes are waves that are commonly called light. Light includes infrared light, visible light, and ultraviolet light. The wavelengths, frequencies, and energy levels of light fall in between those of radio waves on the left and X rays and gamma rays on the right.
When a binary acid only has one acidic hydrogen it is known as what?	xerophyte	triprotic	spirogyra	monoprotic	Most of the binary acids listed here are monoprotic, because they have only one acidic hydrogen. Hydrosulfuric acid, on the other hand is diprotic. Its hydrogen ions are transferred to two water molecules in two subsequent reactions.
Seedless nonvascular plants are small. the dominant stage of the life cycle is the gametophyte. without a vascular system and roots, they absorb water and nutrients through all of their exposed surfaces. there are three main groups: the liverworts, the hornworts, and these?	lichens	algae	mildew	mosses	14.2 Seedless Plants Seedless nonvascular plants are small. The dominant stage of the life cycle is the gametophyte. Without a vascular system and roots, they absorb water and nutrients through all of their exposed surfaces. There are three main groups: the liverworts, the hornworts, and the mosses. They are collectively known as bryophytes.
What is a protein containing four subunits that transports oxygen throughout the body?	keratin	insulin	collagen	hemoglobin	Hemoglobin is a protein containing four subunits that transports oxygen throughout the body.
Molecules that are in continuous motion, travelling in straight lines and changing comprise what state of matter?	plasma	solids	liquids	gases	Gases are composed of molecules that are in continuous motion, travelling in straight lines and changing.
The recombination frequency is the percentage of recombinant flies in the total pool of what?	immigrants	species	samples	offspring	null
Nuclear fusion is a reaction in which two nuclei are combined to form a larger nucleus. it releases energy when light nuclei are fused to form medium-mass nuclei. • fusion is the source of energy in what?	galaxies	Space	orbits	stars	32.5 Fusion • Nuclear fusion is a reaction in which two nuclei are combined to form a larger nucleus. It releases energy when light nuclei are fused to form medium-mass nuclei. • Fusion is the source of energy in stars, with the proton-proton cycle, 1.
What are polymers of amino acids called?	ribosomes	polysaccharides	monopeptides	polypeptides	null
Currently, the only known stable systems undergoing fusion are what?	black holes	plant cells	gas planets	interiors of stars	Fusion occurs in nature: The sun and other stars use fusion as their ultimate energy source. Fusion is also the basis of very destructive weapons that have been developed by several countries around the world. However, one current goal is to develop a source ofcontrolled fusion for use as an energy source. The practical problem is that to perform fusion, extremely high pressures and temperatures are necessary. Currently, the only known stable systems undergoing fusion are the interiors of stars. The conditions necessary for fusion can be created using an atomic bomb, but the resulting fusion is uncontrollable (and the basis for another type of bomb, a hydrogen bomb). Currently, researchers are looking for safe, controlled ways for producing useful energy using fusion.
Displacement is the separation between a beginning position and what other place?	made position	current position	first position	final position	The separation between original and final position is called displacement.
Cellular respiration that proceeds in the absence of oxygen is called what?	aerobic respiration	exasperation	perspiration	anaerobic respiration	Cellular respiration that proceeds in the absence of oxygen is anaerobic respiration.
What is made in the liver and excreted in urine?	blood	feces	plasma	urea	Nitrogenous Waste in Terrestrial Animals: The Urea Cycle The urea cycle is the primary mechanism by which mammals convert ammonia to urea. Urea is made in the liver and excreted in urine. The overall chemical reaction by which ammonia is converted to urea is 2 NH3 (ammonia) + CO2 + 3 ATP + H2O → H2N-CO-NH2 (urea) + 2 ADP + 4 Pi + AMP. The urea cycle utilizes five intermediate steps, catalyzed by five different enzymes, to convert ammonia to urea, as shown in Figure 41.12. The amino acid L-ornithine gets converted into different intermediates before being regenerated at the end of the urea cycle. Hence, the urea cycle is also referred to as the ornithine cycle. The enzyme ornithine transcarbamylase catalyzes a key step in the urea cycle and its deficiency can lead to accumulation of toxic levels of ammonia in the body. The first two reactions occur in the mitochondria and the last three reactions occur in the cytosol. Urea concentration in the blood, called blood urea nitrogen or BUN, is used as an indicator of kidney function.
Name two differences between a larval staged frog and an adult frog.	tadpoles lack legs and gills	tadpoles have legs and gills	tadpoles lack eyes and fins	tadpoles lack legs and have gills	Most amphibians go through a larval stage that is different from the adult form. In frogs, for example, the early larval stage resembles a fish, as you can see in Figure below . Frogs at this stage of development are called tadpoles. Tadpoles live in the water. They lack legs and have a long tail that helps them swim. They also have gills, which absorb oxygen from the water.
What kind of energy can both cause cancer and help in detecting and treating it?	wind	electricity	heat	radiation	Harmless background radiation comes from radioactive elements in rocks and from cosmic rays. Other sources of radiation, such as radon, are harmful. They may cause illness in living things and damage materials such as metals. Radiation has several uses, including detecting and treating cancer.
What was probably the earliest way of making atp from glucose?	fermentation	amniocentesis	photosynthesis	glycolysis	Life first evolved in the absence of oxygen, and glycolysis does not require oxygen. Therefore, glycolysis was probably the earliest way of making ATP from glucose.
What is the process in which a substance naturally moves from an area of higher to lower concentration called?	convection	activation	osmosis	diffusion	Why does passive transport require no energy? A substance naturally moves from an area of higher to lower concentration. This is known as moving down the concentration gradient. The process is called diffusion . It's a little like a ball rolling down a hill. The ball naturally rolls from a higher to lower position without any added energy. You can see diffusion if you place a few drops of food coloring in a pan of water. Even without shaking or stirring, the food coloring gradually spreads throughout the water in the pan. Some substances can also diffuse through a cell membrane. This can occur in two ways: simple diffusion or facilitated diffusion.
What is the internal ph of most living cells?	close to 5	close to 9	close to 6	close to 7	null
What law states whenever one body exerts a force on a second body, the first body experiences a force that is equal in magnitude and opposite in direction to the force that the first body exerts?	equilibrium in forces	law of inertia	law of gravity	symmetry in forces	4.4 Newton’s Third Law of Motion: Symmetry in Forces • Newton’s third law of motion represents a basic symmetry in nature. It states: Whenever one body exerts a force on a second body, the first body experiences a force that is equal in magnitude and opposite in direction to the force that the first body exerts. • A thrust is a reaction force that pushes a body forward in response to a backward force. Rockets, airplanes, and cars are pushed forward by a thrust reaction force.
What does the bicoid protein activate?	spontaneous mutation	enzyme respiration	amino acid production	several gap genes	The bicoid protein activates a number of gap genes. Bicoid encodes a homeodomain-containing transcription factor, and is expressed in a gradient within the embryo. Bicoid positions gap and pair rule gene expression along the anterior-posterior axis of the developing Drosophila embryo.
How do roundworms reproduce?	biologically	asexually	sporadically	sexually	Roundworms reproduce sexually. Sperm and eggs are produced by separate male and female adults. Fertilization takes place inside the female organism. Females lay huge numbers of eggs, sometimes as many as 100,000 per day! The eggs hatch into larvae, which develop into adults. Then the cycle repeats.
Intraspecific competition occurs between members of the same what?	specimens	genus	phylum	species	Competition is a relationship between organisms that strive for the same resources in the same place. Intraspecific competition occurs between members of the same species. It improves the species’ adaptations. Interspecific competition occurs between members of different species. It may lead to one species going extinct or both becoming more specialized.
What is the term for the long-time average of weather?	landscape	evolution	scale	climate	Climate is the long-term average of weather.
What is the most common form of ocean life?	zooplankton	protazoa	phytoplankton	plankton	When you think of life in the ocean, do you think of fish? Actually, fish are not the most common life forms in the ocean. Plankton are the most common. Plankton make up one of three major groups of marine life. The other two groups are nekton and benthos ( Figure below ).
What is the name of the chart that makes it easy to find the possible genotypes in offspring of two parents?	malecela square	Isotropic Square	brindle square	punnett square	A Punnett square is a chart that makes it easy to find the possible genotypes in offspring of two parents. Figure below shows a Punnett square for the two parent pea plants. The gametes produced by the male parent are at the top of the chart. The gametes produced by the female parent are along the left side of the chart. The different possible combinations of alleles in their offspring can be found by filling in the cells of the chart.
What term is used to describe the process of finding the location of genes on each chromosome?	produce mapping	organism mapping	DNA replication	genome mapping	Mapping Genomes Genome mapping is the process of finding the location of genes on each chromosome. The maps that are created are comparable to the maps that we use to navigate streets. A genetic map is an illustration that lists genes and their location on a chromosome. Genetic maps provide the big picture (similar to a map of interstate highways) and use genetic markers (similar to landmarks). A genetic marker is a gene or sequence on a chromosome that shows genetic linkage with a trait of interest. The genetic marker tends to be inherited with the gene of interest, and one measure of distance between them is the recombination frequency during meiosis. Early geneticists called this linkage analysis. Physical maps get into the intimate details of smaller regions of the chromosomes (similar to a detailed road map) (Figure 10.11). A physical map is a representation of the physical distance, in nucleotides, between genes or genetic markers. Both genetic linkage maps and physical maps are required to build a complete picture of the genome. Having a complete map of the genome makes it easier for researchers to study individual genes. Human genome maps help researchers in their efforts to identify human disease-causing genes related to illnesses such as cancer, heart disease, and cystic fibrosis, to name a few. In addition, genome mapping can be used to help identify organisms with beneficial traits, such as microbes with the ability to clean up pollutants or even prevent pollution. Research involving plant genome mapping may lead to methods that produce higher crop yields or to the development of plants that adapt better to climate change.
What is a threat against civilized people called?	bombing	pandemic	disaster	bioterrorism	Bioterrorism is a threat against civilized people worldwide. To be prepared, all levels of government have developed and conducted terrorism drills. These include protecting responders from harmful biological substances.
What are the most common forms of lasers today made of?	spirogyra	prisms	light	silcon	Lasers are constructed from many types of lasing materials, including gases, liquids, solids, and semiconductors. But all lasers are based on the existence of a metastable state or a phosphorescent material. Some lasers produce continuous output; others are pulsed in bursts as brief as 10 −14 s . Some laser outputs are fantastically powerful—some greater than 10 12 W —but the −3 more common, everyday lasers produce something on the order of 10 W . The helium-neon laser that produces a familiar red light is very common. Figure 30.39 shows the energy levels of helium and neon, a pair of noble gases that work well together. An electrical discharge is passed through a helium-neon gas mixture in which the number of atoms of helium is ten times that of neon. The first excited state of helium is metastable and, thus, stores energy. This energy is easily transferred by collision to neon atoms, because they have an excited state at nearly the same energy as that in helium. That state in neon is also metastable, and this is the one that produces the laser output. (The most likely transition is to the nearby state, producing 1.96 eV photons, which have a wavelength of 633 nm and appear red. ) A population inversion can be produced in neon, because there are so many more helium atoms and these put energy into the neon. Helium-neon lasers often have continuous output, because the population inversion can be maintained even while lasing occurs. Probably the most common lasers in use today, including the common laser pointer, are semiconductor or diode lasers, made of silicon. Here, energy is pumped into the material by passing a current in the device to excite the electrons. Special coatings on the ends and fine cleavings of the semiconductor material allow light to bounce back and forth and a tiny fraction to emerge as laser light. Diode lasers can usually run continually and produce outputs in the milliwatt range.
A phospholipid bilayer is made up of two layers of phospholipids, in which hydrophobic fatty acids are in the middle of the what?	cell wall	cells membrane	skin	plasma membrane	A phospholipid is made up of a polar, phosphorus-containing head, and two long fatty acid (hydrocarbon), non-polar "tails. " That is, the head of the molecule is hydrophilic (water-loving), and the tail is hydrophobic (water-fearing). Cytosol and extracellular fluid - the insides and outsides of the cell - are made up of mostly water. In this watery environment, the water loving heads point out towards the water, and the water fearing tails point inwards, and push the water out. The resulting double layer is called a phospholipid bilayer. A phospholipid bilayer is made up of two layers of phospholipids, in which hydrophobic fatty acids are in the middle of the plasma membrane, and the hydrophilic heads are on the outside. An example of a simple phospholipid bilayer is illustrated in Figure below .
The transfer of energy by electromagnetic waves is called what?	magnetic radiation	particulate radiation	mechanical radiation	electromagnetic radiation	Electromagnetic waves are waves that consist of vibrating electric and magnetic fields. Like other waves, electromagnetic waves transfer energy from one place to another. The transfer of energy by electromagnetic waves is called electromagnetic radiation . Electromagnetic waves can transfer energy through matter or across empty space. For an excellent video introduction to electromagnetic waves, go to this URL: http://www. youtube. com/watch?v=cfXzwh3KadE.
The noble gases are unreactive because of their?	carbon content	cell configurations	proton configurations	electron configurations	The noble gases are unreactive because of their electron configurations. The noble gas neon has the electron configuration of 1 s 2 2 s 2 2 p 6 . It has a full outer shell and cannot incorporate any more electrons into the valence shell. The other noble gases have the same outer shell electron configuration even though they have different numbers of inner-shell electrons.
Some birds, such as gulls and terns and other waterfowl have what type of feet used for swimming or floating?	quad toed	bipedal	lobed	webbed	Bird feet can also vary greatly among different birds. Some birds, such as gulls and terns and other waterfowl, have webbed feet used for swimming or floating ( Figure below ). Other birds, such as herons, gallinules, and rails, have four long spreading toes, which are adapted for walking delicately in the wetlands ( Figure below ). You can predict how the beaks and feet of birds will look depending on where they live and what type of food they eat. Flightless birds also have long legs that are adapted for running. Flightless birds include the ostrich and kiwi.
Bones are considered organs because they contain what, specifically?	calcium	DNA	blood	tissue	Bone Tissue Bones are considered organs because they contain various types of tissue, such as blood, connective tissue, nerves, and bone tissue. Osteocytes, the living cells of bone tissue, form the mineral matrix of bones. There are two types of bone tissue: compact and spongy. Compact Bone Tissue Compact bone (or cortical bone) forms the hard external layer of all bones and surrounds the medullary cavity, or bone marrow. It provides protection and strength to bones. Compact bone tissue consists of units called osteons or Haversian systems. Osteons are cylindrical structures that contain a mineral matrix and living osteocytes connected by canaliculi, which transport blood. They are aligned parallel to the long axis of the bone. Each osteon consists of lamellae, which are layers of compact matrix that surround a central canal called the Haversian canal. The Haversian canal (osteonic canal) contains the bone’s blood vessels and nerve fibers (Figure 38.19). Osteons in compact bone tissue are aligned in the same direction along lines of stress and help the bone resist bending or fracturing. Therefore, compact bone tissue is prominent in areas of bone at which stresses are applied in only a few directions.
Plants take in carbon dioxide and give off what?	nitrogen	methane	chlorophyll	oxygen	null
For a scientific theory to be valid, in what way should it be verified?	systematically	directly	optimally	experimentally	For a scientific theory to be valid, it must be verified experimentally. Many parts of the string theory are currently untestable due to the large amount of energy that would be needed to carry out the necessary experiments as well as the high cost of conducting these experiments. Therefore string theory may not be tested in the foreseeable future. Some scientists have even questioned whether it deserves to be called a scientific theory because it is not falsifiable.
For plants, the amount of water, sunlight, nutrients, and space to grow are the important resources, whereas in animals, important resources include food, water, shelter, nesting space, and this?	entertainment	pairs	eggs	mates	Role of Intraspecific Competition The logistic model assumes that every individual within a population will have equal access to resources and, thus, an equal chance for survival. For plants, the amount of water, sunlight, nutrients, and space to grow are the important resources, whereas in animals, important resources include food, water, shelter, nesting space, and mates. In the real world, phenotypic variation among individuals within a population means that some individuals will be better adapted to their environment than others. The resulting competition for resources among population members of the same species is termed intraspecific competition. Intraspecific competition may not affect populations that are well below their carrying capacity, as resources are plentiful and all individuals can obtain what they need. However, as population size increases, this competition intensifies. In addition, the accumulation of waste products can reduce carrying capacity in an environment. Examples of Logistic Growth Yeast, a microscopic fungus used to make bread and alcoholic beverages, exhibits the classical S-shaped curve when grown in a test tube (Figure 19.6a). Its growth levels off as the population depletes the nutrients that are necessary for its growth. In the real world, however, there are variations to this idealized curve. Examples in wild populations include sheep and harbor seals (Figure 19.6b). In both examples, the population size exceeds the carrying capacity for short periods of time and then falls below the carrying capacity afterwards. This fluctuation in population size continues to occur as the population oscillates around its carrying capacity. Still, even with this oscillation, the logistic model is confirmed.
Which is the main organ of the respiratory system?	the liver	the stomach	the mouth	the lungs	When you think of the processes of breathing, the lungs probably come to mind. The lungs are the main organ of the respiratory system. However, many other organs are also needed for the process of respiration to take place.
Why is runoff from artificial fertilizer harmful to the chesapeake bay ecosystem?	leaks food	starts combustion	causes erosion	causes pollution	The Chesapeake Bay has long been valued as one of the most scenic areas on Earth; it is now in distress and is recognized as a declining ecosystem. In the 1970s, the Chesapeake Bay was one of the first ecosystems to have identified dead zones, which continue to kill many fish and bottom-dwelling species, such as clams, oysters, and worms. Several species have declined in the Chesapeake Bay due to surface water runoff containing excess nutrients from artificial fertilizer used on land. The source of the fertilizers (with high nitrogen and phosphate content) is not limited to agricultural practices. There are many nearby urban areas and more than 150 rivers and streams empty into the bay that are carrying fertilizer runoff from lawns and gardens. Thus, the decline of the Chesapeake Bay is a complex issue and requires the cooperation of industry, agriculture, and everyday homeowners. Of particular interest to conservationists is the oyster population; it is estimated that more than 200,000 acres of oyster reefs existed in the bay in the 1700s, but that number has now declined to only 36,000 acres. Oyster harvesting was once a major industry for Chesapeake Bay, but it declined 88 percent between 1982 and 2007. This decline was due not only to fertilizer runoff and dead zones but also to overharvesting. Oysters require a certain minimum population density because they must be in close proximity to reproduce. Human activity has altered the oyster population and locations, greatly disrupting the ecosystem. The restoration of the oyster population in the Chesapeake Bay has been ongoing for several years with mixed success. Not only do many people find oysters good to eat, but they also clean up the bay. Oysters are filter feeders, and as they eat, they clean the water around them. In the 1700s, it was estimated that it took only a few days for the oyster population to filter the entire volume of the bay. Today, with changed water conditions, it is estimated that the present population would take nearly a year to do the same job. Restoration efforts have been ongoing for several years by non-profit organizations, such as the Chesapeake Bay Foundation. The restoration goal is to find a way to increase population density so the oysters can reproduce more efficiently. Many disease-resistant varieties (developed at the Virginia Institute of Marine Science for the College of William and Mary) are now available and have been used in the construction of experimental oyster reefs. Efforts to clean and restore the bay by Virginia and Delaware have been hampered because much of the pollution entering the bay comes from other states, which stresses the need for inter-state cooperation to gain successful restoration.
What system do trees need to transport nutrients?	circulatory	photosynthetic system	passive transport membrane	vascular	The trees tower in the sky, while the mosses carpet the forest floor. Mosses, like the first plants, are restricted to life near the ground because they lack vascular system. Only with a vascular system can these trees transport sugars, nutrients, and water up and down their tall trunks. The evolution of the vascular system was a big step in the evolutionary history of plants.
Food allergies, ulcers, and heartburn all affect what organ system?	nervous system	lymphatic system	skeletal system	digestive system	Many diseases can affect the digestive system. Three of the most common diseases that affect the digestive system are food allergies, ulcers, and heartburn. Foodborne illnesses and food intolerance are also serious issues associated with the digestive system.
Like ammonia, hydrazine is both a brønsted base and which other base?	floyd base	dynamic base	unit base	lewis base	Like ammonia, hydrazine is both a Brønsted base and a Lewis base, although it is weaker than ammonia. It reacts with strong acids and forms two series of salts that contain the N 2 H 5 + and N 2 H 6 2+ ions, respectively. Some rockets use hydrazine as a fuel.
What is the layman's term for a state in which external stimuli are received but not consciously perceived?	dreaming	immunity	homeostasis	sleep	null
What are the tiny, negatively charged particles in an atom that move around the positive nucleus at the center?	neutrons	protons	quarks	electrons	Energy levels (also called electron shells) are fixed distances from the nucleus of an atom where electrons may be found. Electrons are tiny, negatively charged particles in an atom that move around the positive nucleus at the center. Energy levels are a little like the steps of a staircase. You can stand on one step or another but not in between the steps. The same goes for electrons. They can occupy one energy level or another but not the space between energy levels.
Enzymes, antibodies, and muscle fiber are all types of what?	acids	lipids	carbohydrates	proteins	Many important molecules in your body are proteins. Examples include enzymes, antibodies, and muscle fiber. Enzymes are a type of protein that speed up chemical reactions. They are known as "biological catalysts. " For example, your stomach would not be able to break down food if it did not have special enzymes to speed up the rate of digestion. Antibodies that protect you against disease are proteins. Muscle fiber is mostly protein ( Figure below ).
What are formed by the loss of one or two electrons from an element?	isotopes	amines	ions	cations	Cations are formed by the loss of one or two electrons from an element.
Betelgeuse is an example of what "colorful" stage in the life of very massive stars?	blue star	white supergiant	blue supergiant	red supergiant	A more massive star ends its life in a more dramatic way. Very massive stars become red supergiants, like Betelgeuse.
What single word can be defined as the ability to cause change in matter and the ability to do work?	explosion	job	gas	energy	The concept of energy was first introduced in the chapter "States of Matter," where it is defined as the ability to cause change in matter. Energy can also be defined as the ability to do work. Work is done whenever a force is used to move matter. When work is done, energy is transferred from one object to another. For example, when the batter in Figure below uses energy to swing the bat, she transfers energy to the bat. The moving bat, in turn, transfers energy to the ball. Like work, energy is measured in the joule (J), or newton·meter (N·m).
Wearing clothes that trap air next to your body on a cold day helps you retain what type of energy?	alumal energy	adjacent energy	caloric energy	thermal energy	One way to retain your own thermal energy on a cold day is to wear clothes that trap air. That’s because air, like other gases, is a poor conductor of thermal energy. The particles of gases are relatively far apart, so they don’t bump into each other or into other things as often as the more closely spaced particles of liquids or solids. Therefore, particles of gases have fewer opportunities to transfer thermal energy. Materials that are poor thermal conductors are called thermal insulators . Down-filled snowsuits, like those in the Figure below , are good thermal insulators because their feather filling traps a lot of air.
How many steps are involved in blood clotting?	six	two	five	three	Figure 18.14 Hemostasis (a) An injury to a blood vessel initiates the process of hemostasis. Blood clotting involves three steps. First, vascular spasm constricts the flow of blood. Next, a platelet plug forms to temporarily seal small openings in the vessel. Coagulation then enables the repair of the vessel wall once the leakage of blood has stopped. (b) The synthesis of fibrin in blood clots involves either an intrinsic pathway or an extrinsic pathway, both of which lead to a common pathway. (credit a: Kevin MacKenzie).
What type of pressure is the amount of force that is exerted by gases in the air surrounding any given surface?	gravitational	fluid	vapor	atmospheric	Pulmonary ventilation is dependent on three types of pressure: atmospheric, intra-alveolar, and interpleural. Atmospheric pressure is the amount of force that is exerted by gases in the air surrounding any given surface, such as the body. Atmospheric pressure can be expressed in terms of the unit atmosphere, abbreviated atm, or in millimeters of mercury (mm Hg). One atm is equal to 760 mm Hg, which is the atmospheric pressure at sea level. Typically, for respiration, other pressure values are discussed in relation to atmospheric pressure. Therefore, negative pressure is pressure lower than the atmospheric pressure, whereas positive pressure is pressure that it is greater than the atmospheric pressure. A pressure that is equal to the atmospheric pressure is expressed as zero. Intra-alveolar pressure is the pressure of the air within the alveoli, which changes during the different phases of breathing (Figure 22.16). Because the alveoli are connected to the atmosphere via the tubing of the airways (similar to the two- and one-liter containers in the example above), the interpulmonary pressure of the alveoli always equalizes with the atmospheric pressure.

Circadian rhythms and migration are examples of which behaviors?

regular

periodic

natural

cyclic

Types of animal behavior include cyclic behaviors such as circadian rhythms and migration.

Acids are classified based on their what?

diffusion in water

solvency

reaction to gas

ionization in water

Acids are classified as either strong or weak, based on their ionization in water. A strong acid is an acid which is completely ionized in an aqueous solution. Hydrogen chloride (HCl) ionizes completely into hydrogen ions and chloride ions in water.

What type of muscle enables the body to move?

Sartorius

Latissimus Dorsi

gluteus maximus

skeletal muscle

Human Skeletal Muscles. Skeletal muscles enable the body to move.

What results when volcanic ash encircles the globe, blocking the sun and lowering the temperature of the entire planet?

seismic winter

volcanic freeze

seismic apocalypse

volcanic winter

Supervolcanoes are the most dangerous type of volcano. During an eruption, enormous amounts of ash are thrown into the atmosphere. The ash encircles the globe. This blocks the Sun and lowers the temperature of the entire planet. The result is a volcanic winter.

Oxygen and glucose are both reactants in the process of

death

reproduction

birth

cellular respiration

Oxygen and glucose are both reactants in the process of cellular respiration.

Why does the moon evolve around the earth rather than the sun?

stronger magnetic force

stronger planetary force

weaker gravitational force

stronger gravitational force

Objects that are closer together have a stronger force of gravity. For example, the moon is closer to Earth than it is to the more massive sun, so the force of gravity is greater between the moon and Earth than between the moon and the sun. That’s why the moon circles around Earth rather than the sun. This is illustrated in Figure below .

What is an area in a body of water where nothing grows because there is too little oxygen known as?

deceased zone

missing zone

cold zone

dead zone

Rain dissolves fertilizer in the soil. Runoff carries it away. The fertilizer ends up in bodies of water, from ponds to oceans. The nitrogen is a fertilizer in the water bodies. Since there is a lot of nitrogen it causes algae to grow out of control. Figure below shows a pond covered with algae. Algae may use up so much oxygen in the water that nothing else can grow. Soon, even the algae die out. Decomposers break down the dead tissue and use up all the oxygen in the water. This creates a dead zone. A dead zone is an area in a body of water where nothing grows because there is too little oxygen. There is a large dead zone in the Gulf of Mexico. You can see it Figure below .

Most air pollutants can be traced to what source ?

ozone leaks

methane

chemical pollution

fossil fuels

Most air pollutants can be traced to the burning of fossil fuels. Fossil fuels are burned during many processes, including in power plants to create electricity, in factories to make machinery run, in power stoves and furnaces for heating, and in waste facilities. Perhaps one of the biggest uses of fossil fuels is in transportation. Fossil fuels are used in cars, trains, and planes.

A species become separated and becomes two separate species. what can they not do anymore?

eat

grow

defecate

breed

Assume that some members of a species become geographically separated from the rest of the species. If they remain separated long enough, they may evolve genetic differences. If the differences prevent them from interbreeding with members of the original species, they have evolved into a new species. Speciation that occurs in this way is called allopatric speciation . An example is described in Figure below .

A phase diagram plots pressure and what else?

precipitation

oxygen

volume

temperature

Summary The states of matter exhibited by a substance under different temperatures and pressures can be summarized graphically in a phase diagram, which is a plot of pressure versus temperature. Phase diagrams contain discrete regions corresponding to the solid, liquid, and gas phases. The solid and liquid regions are separated by the melting curve of the substance, and the liquid and gas regions are separated by its vapor pressure curve, which ends at the critical point. Within a given region, only a single phase is stable, but along the lines that separate the regions, two phases are in equilibrium at a given temperature and pressure. The lines separating the three phases intersect at a single point, the triple point, which is the only combination of temperature and pressure at which all three phases can coexist in equilibrium. Water has an unusual phase diagram: its melting point decreases with increasing pressure because ice is less dense than liquid water. The phase diagram of carbon dioxide shows that liquid carbon dioxide cannot exist at atmospheric pressure. Consequently, solid carbon dioxide sublimes directly to a gas.

What occurs when the immune system reacts to substances in food as though they were harmful “foreign invaders"?

vomiting

food poisoning

food antibodies

food allergies

Food allergies occur when the immune system reacts to substances in food as though they were harmful “foreign invaders. ” Foods that are most likely to cause allergies are pictured in Figure below . Symptoms of food allergies often include vomiting and diarrhea.

Recycling items actually takes more energy than what other conservation methods that start with "r"?

reusing and reordering

reducing and regurgitating

revision and remembrance

reducing and reusing

We haven’t done as well with the first two “R”s — reducing and reusing. But they aren’t always as easy as recycling. Recycling is better than making things from brand new materials. But it still takes some resources to turn recycled items into new ones. It takes no resources at all to reuse items or not buy them in the first place.

What science studies chemical processes that are found in living things?

psysiology

physiology

marine biology

biochemistry

Biochemistry is the study of chemical processes in living systems. In this chapter, we will explore some of the basic chemical components of biological systems and develop an understanding of the roles played by each major type of biomolecule.

Nonmetals typically lack what capability, because they hold onto their electrons?

mental capacity

magnetic attraction

repelling electricity

conducting electricity

Like most other nonmetals, fluorine cannot conduct electricity, and its electrons explain this as well. An electric current is a flow of electrons. Elements that readily give up electrons (the metals) can carry electric current because their electrons can flow freely. Elements that gain electrons instead of giving them up cannot carry electric current. They hold onto their electrons so they cannot flow.

What is the process called in which populations of organisms change over time?

mutation

generation

emergence

evolution

Evolution is the process by which populations of organisms change over time. It is a process that began on this planet well over 3.5 billion years ago and continues to this day, as populations of organisms continue to change.

An environment reaches its carrying capacity when the number of individual births in it equal the number of what else?

homes

infections

insects

deaths

The carrying capacity of an environment is reached when the number of births equal the number of deaths.

Pulmonary and systemic circulation loops are part of what organ system?

nervous

lymphatic

circulatory

cardiovascular

Compare and contrast the pulmonary and systemic circulation loops of the cardiovascular system.

What are materials that cannot conduct thermal energy efficiently known as?

atmospheric insulators

convection insulators

physical insulators

thermal insulators

Materials that are poor conductors of thermal energy are called thermal insulators. Gases such as air and materials such as plastic and wood are thermal insulators.

The temporomandibular joint (tmj) is the joint that allows for opening (mandibular depression) and closing (mandibular elevation) of this?

eyes

ears

nose

mouth

Temporomandibular Joint The temporomandibular joint (TMJ) is the joint that allows for opening (mandibular depression) and closing (mandibular elevation) of the mouth, as well as side-to-side and protraction/retraction motions of the lower jaw. This joint involves the articulation between the mandibular fossa and articular tubercle of the temporal bone, with the condyle (head) of the mandible. Located between these bony structures, filling the gap between the skull and mandible, is a flexible articular disc (Figure 9.15). This disc serves to smooth the movements between the temporal bone and mandibular condyle. Movement at the TMJ during opening and closing of the mouth involves both gliding and hinge motions of the mandible. With the mouth closed, the mandibular condyle and articular disc are located within the mandibular fossa of the temporal bone. During opening of the mouth, the mandible hinges downward and at the same time is pulled anteriorly, causing both the condyle and the articular disc to glide forward from the mandibular fossa onto the downward projecting articular tubercle. The net result is a forward and downward motion of the condyle and mandibular depression. The temporomandibular joint is supported by an extrinsic ligament that anchors the mandible to the skull. This ligament spans the distance between the base of the skull and the lingula on the medial side of the mandibular ramus. Dislocation of the TMJ may occur when opening the mouth too wide (such as when taking a large bite) or following a blow to the jaw, resulting in the mandibular condyle moving beyond (anterior to) the articular tubercle. In this case, the individual would not be able to close his or her mouth. Temporomandibular joint disorder is a painful condition that may arise due to arthritis, wearing of the articular cartilage covering the bony surfaces of the joint, muscle fatigue from overuse or grinding of the teeth, damage to the articular disc within the joint, or jaw injury. Temporomandibular joint disorders can also cause headache, difficulty chewing, or even the inability to move the jaw (lock jaw). Pharmacologic agents for pain or other therapies, including bite guards, are used as treatments.

What gas consisting of three oxygen atoms is found largely in the stratosphere?

smog

carbon

greenhouse

ozone

Air also includes water vapor. The amount of water vapor varies from place to place. That’s why water vapor isn’t included in Figure above . It can make up as much as 4 percent of the air. Ozone is a molecule made of three oxygen atoms. Ozone collects in a layer in the stratosphere.

Esters can be formed by heating carboxylic acids and alcohols in the presence of?

an oxygen catalyst

a nuclear catalyst

an carbon catalyst

an acid catalyst

Esters can be formed by heating carboxylic acids and alcohols in the presence of an acid catalyst. This process is reversible, and the starting materials can be regenerated by reacting an ester with water in the presence of a weak base.

Glucose that remains in the filtrate of what organ is excreted?

liver

spleen

intestine

kidney

null

What part of a plant helps it reproduce by being ejected from flowers and fruits?

roots

berries

cells

seeds

null

Energy contents of foods are often expressed in what?

nutrients

pulses

grams

calories

One area where the calorie is used is in nutrition. Energy contents of foods are often expressed in calories. However, the calorie unit used for foods is actually the kilocalorie (kcal). Most foods indicate this by spelling the word with a capital C—Calorie. Figure 7.1 "Calories on Food Labels" shows one example. So be careful counting calories when you eat!.

The plasma membranes of cells that specialize in absorption are folded into fingerlike projections called what?

flagella

digits

epithelial

microvilli

The plasma membranes of cells that specialize in absorption are folded into fingerlike projections called microvilli (singular = microvillus); ( Figure 4.10). Such cells are typically found lining the small intestine, the organ that absorbs nutrients from digested food. This is an excellent example of form following function. People with celiac disease have an immune response to gluten, which is a protein found in wheat, barley, and rye. The immune response damages microvilli, and thus, afflicted individuals cannot absorb nutrients. This leads to malnutrition, cramping, and diarrhea. Patients suffering from celiac disease must follow a gluten-free diet.

Sweating and panting are methods mammals use for what purpose?

staying alert

sleeping

staying warm

staying cool

Mammals also have several ways to stay cool, including sweating or panting.

A closed loop through which a current can flow is called what?

powered circuit

charged circuit

cooling circuit

electric circuit

A closed loop through which current can flow is called an electric circuit . In homes in the U. S. , most electric circuits have a voltage of 120 volts. The amount of current (amps) a circuit carries depends on the number and power of electrical devices connected to the circuit. Home circuits generally have a safe upper limit of about 20 or 30 amps.

Unsaturated hydrocarbons with at least one triple bond are known as?

aromatic hydrocarbons

benzenes

alkenes

alkynes

Unsaturated hydrocarbons that contain at least one triple bond are called alkynes . The name of specific alkynes always end in – yne , with a prefix for the number of carbon atoms. Figure below shows the smallest alkyne, called ethyne, which has just two carbon atoms. Ethyne is also called acetylene. It is burned in acetylene torches, like the one in Figure below . Acetylene produces so much heat when it burns that it can melt metal. Breaking all those bonds between carbon atoms releases a lot of energy.

What two types of organism make up a lichen?

snakes and bacteria

insects and bacteria

animals and viruses

fungus and bacteria

Have you ever seen an organism called a lichen? Lichens are crusty, hard growths that you might find on trees, logs, walls, and rocks ( Figure below ). Although lichens may not be the prettiest organisms in nature, they are unique. A lichen is really two organisms, sometimes referred to as a composite organism, that live very closely together: a fungus and a bacterium or an alga. The cells from the alga or bacterium live inside the fungus. Besides providing a home, the fungus also provides nutrients. In turn, the bacterium or the alga provides energy to the fungus by performing photosynthesis, obtaining energy directly from the sun. A lichen is also an example of a mutualistic relationship. Because lichens can grow on rocks, these organisms are some of the earliest life forms in new ecosystems.

The cell regulates most molecules that pass through what cell structure?

protective wall

plasma

ribosome

cell membrane

The cell regulates most molecules that pass through the cell membrane. If a molecule is charged or very big, it won't make it through the cell membrane on its own. However, small, non-charged molecules like oxygen, carbon dioxide, and water, can pass through the cell membrane freely.

What are groups of skeletal muscle fibers wrapped in?

tendons

neurons

collagen

connective tissue

Each skeletal muscle consists of hundreds or even thousands of skeletal muscle fibers . The fibers are bundled together and wrapped in connective tissue, as shown Figure below . The connective tissue supports and protects the delicate muscle cells and allows them to withstand the forces of contraction. It also provides pathways for nerves and blood vessels to reach the muscles. Skeletal muscles work hard to move body parts. They need a rich blood supply to provide them with nutrients and oxygen and to carry away their wastes.

Density is considered what type of property, because it does not depend on the amount of material present in the sample?

exensive property

independent variable

experimental property

intensive property

Density is an intensive property, meaning that it does not depend on the amount of material present in the sample. Water has a density of 1.0 g/mL. That density is the same whether you have a small glass of water or a swimming pool full of water. Density is a property that is constant for the particular identity of the matter being studied.

Prior to binding to a hormone, where are steroid hormone receptors located?

hypothalamus

cortisol

reticulum

cytosol

null

Which scale measures acids and bases and has 7 as a neutral value?

respiration

rock

color

ph

The Concept of pH The relative acidity or alkalinity of a solution can be indicated by its pH. A solution’s pH is the negative, base-10 logarithm of the hydrogen ion (H+) concentration of the solution. As an example, a pH 4 solution has an H+ concentration that is ten times greater than that of a pH 5 solution. That is, a solution with a pH of 4 is ten times more acidic than a solution with a pH of 5. The concept of pH will begin to make more sense when you study the pH scale, like that shown in Figure 2.17. The scale consists of a series of increments ranging from 0 to 14. A solution with a pH of 7 is considered neutral—neither acidic nor basic. Pure water has a pH of 7. The lower the number below 7, the more acidic the solution, or the greater the concentration of H+. The concentration of hydrogen ions at each pH value is 10 times different than the next pH. For instance, a pH value of 4 corresponds to a proton concentration of 10–4 M, or 0.0001M, while a pH value of 5 corresponds to a proton concentration of 10–5 M, or 0.00001M. The higher the number above 7, the more basic (alkaline) the solution, or the lower the concentration of H+. Human urine, for example, is ten times more acidic than pure water, and HCl is 10,000,000 times more acidic than water.

What do we call people who are trained to make specific dietary recommendations to address particular issues relating to health?

pulmonologists

clinicians

geologists

dietitians

Career Focus: Dietitian A dietitian is a nutrition expert who communicates food-related information to the general public. In doing so, dietitians promote the general well-being among the population and help individuals recover from nutritionally related illnesses. Our diet does not just supply us with energy. We also get vitamins, minerals, and even water from what we eat. Eating too much, too little, or not enough of the right foods can lead to a variety of problems. Dietitians are trained to make specific dietary recommendations to address particular issues relating to health. For example, a dietitian might work with a person to develop an overall diet that would help that person lose weight or control diabetes. Hospitals employ dietitians in planning menus for patients, and many dietitians work with community organizations to improve the eating habits of large groups of people.

An artery is a blood vessel that conducts blood away from the what?

lung

stomach

brain

heart

Arteries An artery is a blood vessel that conducts blood away from the heart. All arteries have relatively thick walls that can withstand the high pressure of blood ejected from the heart. However, those close to the heart have the thickest walls, containing a high percentage of elastic fibers in all three of their tunics. This type of artery is known as an elastic artery (Figure 20.4). Vessels larger than 10 mm in diameter are typically elastic. Their abundant elastic fibers allow them to expand, as blood pumped from the ventricles passes through them, and then to recoil after the surge has passed. If artery walls were rigid and unable to expand and recoil, their resistance to blood flow would greatly increase and blood pressure would rise to even higher levels, which would in turn require the heart to pump harder to increase the volume of blood expelled by each pump (the stroke volume) and maintain adequate pressure and flow. Artery walls would have to become even thicker in response to this increased pressure. The elastic recoil of the vascular wall helps to maintain the pressure gradient that drives the blood through the arterial system. An elastic artery is also known as a conducting artery, because the large diameter of the lumen enables it to accept a large volume of blood from the heart and conduct it to smaller branches.

The small amount of energy input necessary for all chemical reactions to occur is called what?

decomposition energy

nuclear energy

distinct energy

activation energy

Activation Energy There is another important concept that must be considered regarding endergonic and exergonic reactions. Even exergonic reactions require a small amount of energy input to get going before they can proceed with their energy-releasing steps. These reactions have a net release of energy, but still require some energy in the beginning. This small amount of energy input necessary for all chemical reactions to occur is called the activation energy (or free energy of activation) and is abbreviated EA (Figure 6.10). Why would an energy-releasing, negative ∆G reaction actually require some energy to proceed? The reason lies in the steps that take place during a chemical reaction. During chemical reactions, certain chemical bonds are broken and new ones are formed. For example, when a glucose molecule is broken down, bonds between the carbon atoms of the molecule are broken. Since these are energy-storing bonds, they release energy when broken. However, to get them into a state that allows the bonds to break, the molecule must be somewhat contorted. A small energy input is required to achieve this contorted state. This contorted state is called the transition state, and it is a high-energy, unstable state. For this reason, reactant molecules don’t last long in their transition state, but very quickly proceed to the next steps of the chemical reaction. Free energy diagrams illustrate the energy profiles for a given reaction. Whether the reaction is exergonic or endergonic determines whether the products in the diagram will exist at a lower or higher energy state than both the reactants and the products. However, regardless of this measure, the transition state of the reaction exists at a higher energy state than the reactants, and thus, EA is always positive.

What linear polymer of glucose units is found in plants and serves a structural purpose?

sucrose

frucose

carbonate

cellulose

Cellulose is a structural polymer of glucose units found in plants. It is a linear polymer with the glucose units linked through β-1,4-glycosidic bonds.

When the temperature of water is increased after being used in cooling, it is this form of pollution?

air

atmospheric

cosmic

thermal

Thermal pollution is pollution that raises the temperature of water. This is caused by power plants and factories that use the water to cool their machines. The plants pump cold water from a lake or coastal area through giant cooling towers, like those in Figure below . As it flows through the towers, the cold water absorbs heat. This warmed water is returned to the lake or sea. Thermal pollution can kill fish and other water life. It's not just the warm temperature that kills them. Warm water can’t hold as much oxygen as cool water. If the water gets too warm, there may not be enough oxygen for living things.

Which biological system is responsible for getting rid of chemical waste and water?

digestive system

endocrine system

mucous system

urinary system

null

What part of the body protects the brain?

lungs

feet

arms

cranium (skull)

The cranium (skull) to protect the brain. The brain is attached to the spinal cord.

Ammonium nitrate and ammonium sulfate are used in fertilizers as a source of what?

biofuel

bacteria

oxygen

nitrogen

Ammonium nitrate and ammonium sulfate are used in fertilizers as a source of nitrogen. The ammonium cation is tetrahedral. Refer to Section 2.1 "Chemical Compounds" to draw the structure of the ammonium ion.

What kind of light bulb has a tungsten filament?

sodium

fluorescent

translucent

incandescent

An incandescent light bulb like the one pictured in the Figure below produces visible light by incandescence. Incandescence occurs when something gets so hot that it glows. An incandescent light bulb contains a thin wire filament made of tungsten. When electric current passes through the filament, it gets extremely hot and emits light.

What is the name for the circle that runs north to south and passes through greenwich, england?

equator

odd meridian

time zone

prime meridian

Lines of longitude are circles that go around Earth from pole to pole, like the sections of an orange. Longitude is also measured in degrees, which are subdivided into minutes and seconds. Lines of longitude start at the Prime Meridian, which is 0°. The Prime Meridian is a circle that runs north to south and passes through Greenwich, England. Longitude tells you how far you are east or west from the Prime Meridian ( Figure below ). On the opposite side of the planet from the Prime Meridian is the International Date Line. It is at 180°. This is the place where a new day first arrives.

What map coordinates correspond to similar climate zones and life zones?

latitude and longitude

equator and poles

the poles

altitude and latitude

Altitude and latitude produce similar climate zones and life zones.

In myasthenia gravis, antibodies bind to and block certain receptors on muscle cells, preventing what?

muscle buildup

muscle layer

muscle diffusion

muscle contraction

null

What helps cells reduce their reaction to excessive hormone levels?

evaporation

apoptosis

adhesion

downregulation

Factors Affecting Target Cell Response You will recall that target cells must have receptors specific to a given hormone if that hormone is to trigger a response. But several other factors influence the target cell response. For example, the presence of a significant level of a hormone circulating in the bloodstream can cause its target cells to decrease their number of receptors for that hormone. This process is called downregulation, and it allows cells to become less reactive to the excessive hormone levels. When the level of a hormone is chronically reduced, target cells engage in upregulation to increase their number of receptors. This process allows cells to be more sensitive to the hormone that is present. Cells can also alter the sensitivity of the receptors themselves to various hormones. Two or more hormones can interact to affect the response of cells in a variety of ways. The three most common types of interaction are as follows: • The permissive effect, in which the presence of one hormone enables another hormone to act. For example, thyroid hormones have complex permissive relationships with certain reproductive hormones. A dietary deficiency of iodine, a component of thyroid hormones, can therefore affect reproductive system development and functioning. • The synergistic effect, in which two hormones with similar effects produce an amplified response. In some cases, two hormones are required for an adequate response. For example, two different reproductive hormones—FSH from the pituitary gland and estrogens from the ovaries—are required for the maturation of female ova (egg cells). • The antagonistic effect, in which two hormones have opposing effects. A familiar example is the effect of two pancreatic hormones, insulin and glucagon. Insulin increases the liver’s storage of glucose as glycogen, decreasing blood glucose, whereas glucagon stimulates the breakdown of glycogen stores, increasing blood glucose.

Smog is an example of the formation of what kind of pollutant, which occurs when primary pollutants undergo chemical reactions after they are released?

primary pollutant

combined pollutant

tertiary pollutant

secondary pollutant

Primary pollutants enter the air directly. They include carbon, nitrogen, and sulfur oxides. Toxic heavy metals, VOCs, and particulates are also primary pollutants. Secondary pollutants form when primary pollutants undergo chemical reactions after they are released. Many occur as part of photochemical smog. The main component of smog is ozone.

What occurs when a sperm and an egg fuse?

infection

migration

pollination

fertilization

Many animals have a relatively simple life cycle. A general animal life cycle is shown in Figure below . Most animals spend the majority of their life as diploid organisms. Just about all animals reproduce sexually. Diploid adults undergo meiosis to produce haploid sperm or eggs. Fertilization occurs when a sperm and an egg fuse. The diploid zygote that forms develops into an embryo. The embryo eventually develops into an adult, often going through one or more larval stages on the way. A larva (larvae, plural) is a distinct juvenile form that many animals go through before becoming an adult. The larval form may be very different from the adult form. For example, a caterpillar is the larval form of an insect that becomes a butterfly as an adult.

How many bases does dna have in total?

six

three

twelve

four

Every DNA and RNA polymer consists of multiple nucleotides strung together into extremely long chains. The only variation in each nucleotide is the identity of the nitrogenous base. The figure above shows one example of a nitrogenous base, called adenine. There are only five different nitrogenous bases found in all nucleic acids. The four bases of DNA are adenine, thymine, cytosine, and guanine, abbreviated A, T, C, and G respectively. In RNA, the base thymine is not found and is instead replaced by a different base called uracil, abbreviated U. The other three bases are present in both DNA and RNA.

Compound machines tend to have a greater mechanical advantage than what other machines?

digital machines

levers

magnets

simple machines

The mechanical advantage of a machine is the factor by which it changes the force applied to the machine. Many machines increase the force applied to them, and this is how they make work easier. Compound machines tend to have a greater mechanical advantage than simple machines. That’s because the mechanical advantage of a compound machine equals the product of the mechanical advantages of all its component simple machines. The greater the number of simple machines it contains, the greater its mechanical advantage tends to be.

Name the missing type of light: ultraviolet, infrared, ___________.

distinct

vertical

predictable

visible

Between these two extremes are waves that are commonly called light. Light includes infrared light, visible light, and ultraviolet light. The wavelengths, frequencies, and energy levels of light fall in between those of radio waves on the left and X rays and gamma rays on the right.

When a binary acid only has one acidic hydrogen it is known as what?

xerophyte

triprotic

spirogyra

monoprotic

Most of the binary acids listed here are monoprotic, because they have only one acidic hydrogen. Hydrosulfuric acid, on the other hand is diprotic. Its hydrogen ions are transferred to two water molecules in two subsequent reactions.

Seedless nonvascular plants are small. the dominant stage of the life cycle is the gametophyte. without a vascular system and roots, they absorb water and nutrients through all of their exposed surfaces. there are three main groups: the liverworts, the hornworts, and these?

lichens

algae

mildew

mosses

14.2 Seedless Plants Seedless nonvascular plants are small. The dominant stage of the life cycle is the gametophyte. Without a vascular system and roots, they absorb water and nutrients through all of their exposed surfaces. There are three main groups: the liverworts, the hornworts, and the mosses. They are collectively known as bryophytes.

What is a protein containing four subunits that transports oxygen throughout the body?

keratin

insulin

collagen

hemoglobin

Hemoglobin is a protein containing four subunits that transports oxygen throughout the body.

Molecules that are in continuous motion, travelling in straight lines and changing comprise what state of matter?

plasma

solids

liquids

gases

Gases are composed of molecules that are in continuous motion, travelling in straight lines and changing.

The recombination frequency is the percentage of recombinant flies in the total pool of what?

immigrants

species

samples

offspring

null

Nuclear fusion is a reaction in which two nuclei are combined to form a larger nucleus. it releases energy when light nuclei are fused to form medium-mass nuclei. • fusion is the source of energy in what?

galaxies

Space

orbits

stars

32.5 Fusion • Nuclear fusion is a reaction in which two nuclei are combined to form a larger nucleus. It releases energy when light nuclei are fused to form medium-mass nuclei. • Fusion is the source of energy in stars, with the proton-proton cycle, 1.

What are polymers of amino acids called?

ribosomes

polysaccharides

monopeptides

polypeptides

null

Currently, the only known stable systems undergoing fusion are what?

black holes

plant cells

gas planets

interiors of stars

Fusion occurs in nature: The sun and other stars use fusion as their ultimate energy source. Fusion is also the basis of very destructive weapons that have been developed by several countries around the world. However, one current goal is to develop a source ofcontrolled fusion for use as an energy source. The practical problem is that to perform fusion, extremely high pressures and temperatures are necessary. Currently, the only known stable systems undergoing fusion are the interiors of stars. The conditions necessary for fusion can be created using an atomic bomb, but the resulting fusion is uncontrollable (and the basis for another type of bomb, a hydrogen bomb). Currently, researchers are looking for safe, controlled ways for producing useful energy using fusion.

Displacement is the separation between a beginning position and what other place?

made position

current position

first position

final position

The separation between original and final position is called displacement.

Cellular respiration that proceeds in the absence of oxygen is called what?

aerobic respiration

exasperation

perspiration

anaerobic respiration

Cellular respiration that proceeds in the absence of oxygen is anaerobic respiration.

What is made in the liver and excreted in urine?

blood

feces

plasma

urea

Nitrogenous Waste in Terrestrial Animals: The Urea Cycle The urea cycle is the primary mechanism by which mammals convert ammonia to urea. Urea is made in the liver and excreted in urine. The overall chemical reaction by which ammonia is converted to urea is 2 NH3 (ammonia) + CO2 + 3 ATP + H2O → H2N-CO-NH2 (urea) + 2 ADP + 4 Pi + AMP. The urea cycle utilizes five intermediate steps, catalyzed by five different enzymes, to convert ammonia to urea, as shown in Figure 41.12. The amino acid L-ornithine gets converted into different intermediates before being regenerated at the end of the urea cycle. Hence, the urea cycle is also referred to as the ornithine cycle. The enzyme ornithine transcarbamylase catalyzes a key step in the urea cycle and its deficiency can lead to accumulation of toxic levels of ammonia in the body. The first two reactions occur in the mitochondria and the last three reactions occur in the cytosol. Urea concentration in the blood, called blood urea nitrogen or BUN, is used as an indicator of kidney function.

Name two differences between a larval staged frog and an adult frog.

tadpoles lack legs and gills

tadpoles have legs and gills

tadpoles lack eyes and fins

tadpoles lack legs and have gills

Most amphibians go through a larval stage that is different from the adult form. In frogs, for example, the early larval stage resembles a fish, as you can see in Figure below . Frogs at this stage of development are called tadpoles. Tadpoles live in the water. They lack legs and have a long tail that helps them swim. They also have gills, which absorb oxygen from the water.

What kind of energy can both cause cancer and help in detecting and treating it?

wind

electricity

heat

radiation

Harmless background radiation comes from radioactive elements in rocks and from cosmic rays. Other sources of radiation, such as radon, are harmful. They may cause illness in living things and damage materials such as metals. Radiation has several uses, including detecting and treating cancer.

What was probably the earliest way of making atp from glucose?

fermentation

amniocentesis

photosynthesis

glycolysis

Life first evolved in the absence of oxygen, and glycolysis does not require oxygen. Therefore, glycolysis was probably the earliest way of making ATP from glucose.

What is the process in which a substance naturally moves from an area of higher to lower concentration called?

convection

activation

osmosis

diffusion

Why does passive transport require no energy? A substance naturally moves from an area of higher to lower concentration. This is known as moving down the concentration gradient. The process is called diffusion . It's a little like a ball rolling down a hill. The ball naturally rolls from a higher to lower position without any added energy. You can see diffusion if you place a few drops of food coloring in a pan of water. Even without shaking or stirring, the food coloring gradually spreads throughout the water in the pan. Some substances can also diffuse through a cell membrane. This can occur in two ways: simple diffusion or facilitated diffusion.

What is the internal ph of most living cells?

close to 5

close to 9

close to 6

close to 7

null

What law states whenever one body exerts a force on a second body, the first body experiences a force that is equal in magnitude and opposite in direction to the force that the first body exerts?

equilibrium in forces

law of inertia

law of gravity

symmetry in forces

4.4 Newton’s Third Law of Motion: Symmetry in Forces • Newton’s third law of motion represents a basic symmetry in nature. It states: Whenever one body exerts a force on a second body, the first body experiences a force that is equal in magnitude and opposite in direction to the force that the first body exerts. • A thrust is a reaction force that pushes a body forward in response to a backward force. Rockets, airplanes, and cars are pushed forward by a thrust reaction force.

What does the bicoid protein activate?

spontaneous mutation

enzyme respiration

amino acid production

several gap genes

The bicoid protein activates a number of gap genes. Bicoid encodes a homeodomain-containing transcription factor, and is expressed in a gradient within the embryo. Bicoid positions gap and pair rule gene expression along the anterior-posterior axis of the developing Drosophila embryo.

How do roundworms reproduce?

biologically

asexually

sporadically

sexually

Roundworms reproduce sexually. Sperm and eggs are produced by separate male and female adults. Fertilization takes place inside the female organism. Females lay huge numbers of eggs, sometimes as many as 100,000 per day! The eggs hatch into larvae, which develop into adults. Then the cycle repeats.

Intraspecific competition occurs between members of the same what?

specimens

genus

phylum

species

Competition is a relationship between organisms that strive for the same resources in the same place. Intraspecific competition occurs between members of the same species. It improves the species’ adaptations. Interspecific competition occurs between members of different species. It may lead to one species going extinct or both becoming more specialized.

What is the term for the long-time average of weather?

landscape

evolution

scale

climate

Climate is the long-term average of weather.

What is the most common form of ocean life?

zooplankton

protazoa

phytoplankton

plankton

When you think of life in the ocean, do you think of fish? Actually, fish are not the most common life forms in the ocean. Plankton are the most common. Plankton make up one of three major groups of marine life. The other two groups are nekton and benthos ( Figure below ).

What is the name of the chart that makes it easy to find the possible genotypes in offspring of two parents?

malecela square

Isotropic Square

brindle square

punnett square

A Punnett square is a chart that makes it easy to find the possible genotypes in offspring of two parents. Figure below shows a Punnett square for the two parent pea plants. The gametes produced by the male parent are at the top of the chart. The gametes produced by the female parent are along the left side of the chart. The different possible combinations of alleles in their offspring can be found by filling in the cells of the chart.

What term is used to describe the process of finding the location of genes on each chromosome?

produce mapping

organism mapping

DNA replication

genome mapping

Mapping Genomes Genome mapping is the process of finding the location of genes on each chromosome. The maps that are created are comparable to the maps that we use to navigate streets. A genetic map is an illustration that lists genes and their location on a chromosome. Genetic maps provide the big picture (similar to a map of interstate highways) and use genetic markers (similar to landmarks). A genetic marker is a gene or sequence on a chromosome that shows genetic linkage with a trait of interest. The genetic marker tends to be inherited with the gene of interest, and one measure of distance between them is the recombination frequency during meiosis. Early geneticists called this linkage analysis. Physical maps get into the intimate details of smaller regions of the chromosomes (similar to a detailed road map) (Figure 10.11). A physical map is a representation of the physical distance, in nucleotides, between genes or genetic markers. Both genetic linkage maps and physical maps are required to build a complete picture of the genome. Having a complete map of the genome makes it easier for researchers to study individual genes. Human genome maps help researchers in their efforts to identify human disease-causing genes related to illnesses such as cancer, heart disease, and cystic fibrosis, to name a few. In addition, genome mapping can be used to help identify organisms with beneficial traits, such as microbes with the ability to clean up pollutants or even prevent pollution. Research involving plant genome mapping may lead to methods that produce higher crop yields or to the development of plants that adapt better to climate change.

What is a threat against civilized people called?

bombing

pandemic

disaster

bioterrorism

Bioterrorism is a threat against civilized people worldwide. To be prepared, all levels of government have developed and conducted terrorism drills. These include protecting responders from harmful biological substances.

What are the most common forms of lasers today made of?

spirogyra

prisms

light

silcon

Lasers are constructed from many types of lasing materials, including gases, liquids, solids, and semiconductors. But all lasers are based on the existence of a metastable state or a phosphorescent material. Some lasers produce continuous output; others are pulsed in bursts as brief as 10 −14 s . Some laser outputs are fantastically powerful—some greater than 10 12 W —but the −3 more common, everyday lasers produce something on the order of 10 W . The helium-neon laser that produces a familiar red light is very common. Figure 30.39 shows the energy levels of helium and neon, a pair of noble gases that work well together. An electrical discharge is passed through a helium-neon gas mixture in which the number of atoms of helium is ten times that of neon. The first excited state of helium is metastable and, thus, stores energy. This energy is easily transferred by collision to neon atoms, because they have an excited state at nearly the same energy as that in helium. That state in neon is also metastable, and this is the one that produces the laser output. (The most likely transition is to the nearby state, producing 1.96 eV photons, which have a wavelength of 633 nm and appear red. ) A population inversion can be produced in neon, because there are so many more helium atoms and these put energy into the neon. Helium-neon lasers often have continuous output, because the population inversion can be maintained even while lasing occurs. Probably the most common lasers in use today, including the common laser pointer, are semiconductor or diode lasers, made of silicon. Here, energy is pumped into the material by passing a current in the device to excite the electrons. Special coatings on the ends and fine cleavings of the semiconductor material allow light to bounce back and forth and a tiny fraction to emerge as laser light. Diode lasers can usually run continually and produce outputs in the milliwatt range.

A phospholipid bilayer is made up of two layers of phospholipids, in which hydrophobic fatty acids are in the middle of the what?

cell wall

cells membrane

skin

plasma membrane

A phospholipid is made up of a polar, phosphorus-containing head, and two long fatty acid (hydrocarbon), non-polar "tails. " That is, the head of the molecule is hydrophilic (water-loving), and the tail is hydrophobic (water-fearing). Cytosol and extracellular fluid - the insides and outsides of the cell - are made up of mostly water. In this watery environment, the water loving heads point out towards the water, and the water fearing tails point inwards, and push the water out. The resulting double layer is called a phospholipid bilayer. A phospholipid bilayer is made up of two layers of phospholipids, in which hydrophobic fatty acids are in the middle of the plasma membrane, and the hydrophilic heads are on the outside. An example of a simple phospholipid bilayer is illustrated in Figure below .

The transfer of energy by electromagnetic waves is called what?

magnetic radiation

particulate radiation

mechanical radiation

electromagnetic radiation

Electromagnetic waves are waves that consist of vibrating electric and magnetic fields. Like other waves, electromagnetic waves transfer energy from one place to another. The transfer of energy by electromagnetic waves is called electromagnetic radiation . Electromagnetic waves can transfer energy through matter or across empty space. For an excellent video introduction to electromagnetic waves, go to this URL: http://www. youtube. com/watch?v=cfXzwh3KadE.

The noble gases are unreactive because of their?

carbon content

cell configurations

proton configurations

electron configurations

The noble gases are unreactive because of their electron configurations. The noble gas neon has the electron configuration of 1 s 2 2 s 2 2 p 6 . It has a full outer shell and cannot incorporate any more electrons into the valence shell. The other noble gases have the same outer shell electron configuration even though they have different numbers of inner-shell electrons.

Some birds, such as gulls and terns and other waterfowl have what type of feet used for swimming or floating?

quad toed

bipedal

lobed

webbed

Bird feet can also vary greatly among different birds. Some birds, such as gulls and terns and other waterfowl, have webbed feet used for swimming or floating ( Figure below ). Other birds, such as herons, gallinules, and rails, have four long spreading toes, which are adapted for walking delicately in the wetlands ( Figure below ). You can predict how the beaks and feet of birds will look depending on where they live and what type of food they eat. Flightless birds also have long legs that are adapted for running. Flightless birds include the ostrich and kiwi.

Bones are considered organs because they contain what, specifically?

calcium

DNA

blood

tissue

Bone Tissue Bones are considered organs because they contain various types of tissue, such as blood, connective tissue, nerves, and bone tissue. Osteocytes, the living cells of bone tissue, form the mineral matrix of bones. There are two types of bone tissue: compact and spongy. Compact Bone Tissue Compact bone (or cortical bone) forms the hard external layer of all bones and surrounds the medullary cavity, or bone marrow. It provides protection and strength to bones. Compact bone tissue consists of units called osteons or Haversian systems. Osteons are cylindrical structures that contain a mineral matrix and living osteocytes connected by canaliculi, which transport blood. They are aligned parallel to the long axis of the bone. Each osteon consists of lamellae, which are layers of compact matrix that surround a central canal called the Haversian canal. The Haversian canal (osteonic canal) contains the bone’s blood vessels and nerve fibers (Figure 38.19). Osteons in compact bone tissue are aligned in the same direction along lines of stress and help the bone resist bending or fracturing. Therefore, compact bone tissue is prominent in areas of bone at which stresses are applied in only a few directions.

Plants take in carbon dioxide and give off what?

nitrogen

methane

chlorophyll

oxygen

null

For a scientific theory to be valid, in what way should it be verified?

systematically

directly

optimally

experimentally

For a scientific theory to be valid, it must be verified experimentally. Many parts of the string theory are currently untestable due to the large amount of energy that would be needed to carry out the necessary experiments as well as the high cost of conducting these experiments. Therefore string theory may not be tested in the foreseeable future. Some scientists have even questioned whether it deserves to be called a scientific theory because it is not falsifiable.

For plants, the amount of water, sunlight, nutrients, and space to grow are the important resources, whereas in animals, important resources include food, water, shelter, nesting space, and this?

entertainment

pairs

eggs

mates

Role of Intraspecific Competition The logistic model assumes that every individual within a population will have equal access to resources and, thus, an equal chance for survival. For plants, the amount of water, sunlight, nutrients, and space to grow are the important resources, whereas in animals, important resources include food, water, shelter, nesting space, and mates. In the real world, phenotypic variation among individuals within a population means that some individuals will be better adapted to their environment than others. The resulting competition for resources among population members of the same species is termed intraspecific competition. Intraspecific competition may not affect populations that are well below their carrying capacity, as resources are plentiful and all individuals can obtain what they need. However, as population size increases, this competition intensifies. In addition, the accumulation of waste products can reduce carrying capacity in an environment. Examples of Logistic Growth Yeast, a microscopic fungus used to make bread and alcoholic beverages, exhibits the classical S-shaped curve when grown in a test tube (Figure 19.6a). Its growth levels off as the population depletes the nutrients that are necessary for its growth. In the real world, however, there are variations to this idealized curve. Examples in wild populations include sheep and harbor seals (Figure 19.6b). In both examples, the population size exceeds the carrying capacity for short periods of time and then falls below the carrying capacity afterwards. This fluctuation in population size continues to occur as the population oscillates around its carrying capacity. Still, even with this oscillation, the logistic model is confirmed.

Which is the main organ of the respiratory system?

the liver

the stomach

the mouth

the lungs

When you think of the processes of breathing, the lungs probably come to mind. The lungs are the main organ of the respiratory system. However, many other organs are also needed for the process of respiration to take place.

Why is runoff from artificial fertilizer harmful to the chesapeake bay ecosystem?

leaks food

starts combustion

causes erosion

causes pollution

The Chesapeake Bay has long been valued as one of the most scenic areas on Earth; it is now in distress and is recognized as a declining ecosystem. In the 1970s, the Chesapeake Bay was one of the first ecosystems to have identified dead zones, which continue to kill many fish and bottom-dwelling species, such as clams, oysters, and worms. Several species have declined in the Chesapeake Bay due to surface water runoff containing excess nutrients from artificial fertilizer used on land. The source of the fertilizers (with high nitrogen and phosphate content) is not limited to agricultural practices. There are many nearby urban areas and more than 150 rivers and streams empty into the bay that are carrying fertilizer runoff from lawns and gardens. Thus, the decline of the Chesapeake Bay is a complex issue and requires the cooperation of industry, agriculture, and everyday homeowners. Of particular interest to conservationists is the oyster population; it is estimated that more than 200,000 acres of oyster reefs existed in the bay in the 1700s, but that number has now declined to only 36,000 acres. Oyster harvesting was once a major industry for Chesapeake Bay, but it declined 88 percent between 1982 and 2007. This decline was due not only to fertilizer runoff and dead zones but also to overharvesting. Oysters require a certain minimum population density because they must be in close proximity to reproduce. Human activity has altered the oyster population and locations, greatly disrupting the ecosystem. The restoration of the oyster population in the Chesapeake Bay has been ongoing for several years with mixed success. Not only do many people find oysters good to eat, but they also clean up the bay. Oysters are filter feeders, and as they eat, they clean the water around them. In the 1700s, it was estimated that it took only a few days for the oyster population to filter the entire volume of the bay. Today, with changed water conditions, it is estimated that the present population would take nearly a year to do the same job. Restoration efforts have been ongoing for several years by non-profit organizations, such as the Chesapeake Bay Foundation. The restoration goal is to find a way to increase population density so the oysters can reproduce more efficiently. Many disease-resistant varieties (developed at the Virginia Institute of Marine Science for the College of William and Mary) are now available and have been used in the construction of experimental oyster reefs. Efforts to clean and restore the bay by Virginia and Delaware have been hampered because much of the pollution entering the bay comes from other states, which stresses the need for inter-state cooperation to gain successful restoration.

What system do trees need to transport nutrients?

circulatory

photosynthetic system

passive transport membrane

vascular

The trees tower in the sky, while the mosses carpet the forest floor. Mosses, like the first plants, are restricted to life near the ground because they lack vascular system. Only with a vascular system can these trees transport sugars, nutrients, and water up and down their tall trunks. The evolution of the vascular system was a big step in the evolutionary history of plants.

Food allergies, ulcers, and heartburn all affect what organ system?

nervous system

lymphatic system

skeletal system

digestive system

Many diseases can affect the digestive system. Three of the most common diseases that affect the digestive system are food allergies, ulcers, and heartburn. Foodborne illnesses and food intolerance are also serious issues associated with the digestive system.

Like ammonia, hydrazine is both a brønsted base and which other base?

floyd base

dynamic base

unit base

lewis base

Like ammonia, hydrazine is both a Brønsted base and a Lewis base, although it is weaker than ammonia. It reacts with strong acids and forms two series of salts that contain the N 2 H 5 + and N 2 H 6 2+ ions, respectively. Some rockets use hydrazine as a fuel.

What is the layman's term for a state in which external stimuli are received but not consciously perceived?

dreaming

immunity

homeostasis

sleep

null

What are the tiny, negatively charged particles in an atom that move around the positive nucleus at the center?

neutrons

protons

quarks

electrons

Energy levels (also called electron shells) are fixed distances from the nucleus of an atom where electrons may be found. Electrons are tiny, negatively charged particles in an atom that move around the positive nucleus at the center. Energy levels are a little like the steps of a staircase. You can stand on one step or another but not in between the steps. The same goes for electrons. They can occupy one energy level or another but not the space between energy levels.

Enzymes, antibodies, and muscle fiber are all types of what?

acids

lipids

carbohydrates

proteins

Many important molecules in your body are proteins. Examples include enzymes, antibodies, and muscle fiber. Enzymes are a type of protein that speed up chemical reactions. They are known as "biological catalysts. " For example, your stomach would not be able to break down food if it did not have special enzymes to speed up the rate of digestion. Antibodies that protect you against disease are proteins. Muscle fiber is mostly protein ( Figure below ).

What are formed by the loss of one or two electrons from an element?

isotopes

amines

ions

cations

Cations are formed by the loss of one or two electrons from an element.

Betelgeuse is an example of what "colorful" stage in the life of very massive stars?

blue star

white supergiant

blue supergiant

red supergiant

A more massive star ends its life in a more dramatic way. Very massive stars become red supergiants, like Betelgeuse.

What single word can be defined as the ability to cause change in matter and the ability to do work?

explosion

job

gas

energy

The concept of energy was first introduced in the chapter "States of Matter," where it is defined as the ability to cause change in matter. Energy can also be defined as the ability to do work. Work is done whenever a force is used to move matter. When work is done, energy is transferred from one object to another. For example, when the batter in Figure below uses energy to swing the bat, she transfers energy to the bat. The moving bat, in turn, transfers energy to the ball. Like work, energy is measured in the joule (J), or newton·meter (N·m).

Wearing clothes that trap air next to your body on a cold day helps you retain what type of energy?

alumal energy

adjacent energy

caloric energy

thermal energy

One way to retain your own thermal energy on a cold day is to wear clothes that trap air. That’s because air, like other gases, is a poor conductor of thermal energy. The particles of gases are relatively far apart, so they don’t bump into each other or into other things as often as the more closely spaced particles of liquids or solids. Therefore, particles of gases have fewer opportunities to transfer thermal energy. Materials that are poor thermal conductors are called thermal insulators . Down-filled snowsuits, like those in the Figure below , are good thermal insulators because their feather filling traps a lot of air.

How many steps are involved in blood clotting?

six

two

five

three

Figure 18.14 Hemostasis (a) An injury to a blood vessel initiates the process of hemostasis. Blood clotting involves three steps. First, vascular spasm constricts the flow of blood. Next, a platelet plug forms to temporarily seal small openings in the vessel. Coagulation then enables the repair of the vessel wall once the leakage of blood has stopped. (b) The synthesis of fibrin in blood clots involves either an intrinsic pathway or an extrinsic pathway, both of which lead to a common pathway. (credit a: Kevin MacKenzie).

What type of pressure is the amount of force that is exerted by gases in the air surrounding any given surface?

gravitational

fluid

vapor

atmospheric

Pulmonary ventilation is dependent on three types of pressure: atmospheric, intra-alveolar, and interpleural. Atmospheric pressure is the amount of force that is exerted by gases in the air surrounding any given surface, such as the body. Atmospheric pressure can be expressed in terms of the unit atmosphere, abbreviated atm, or in millimeters of mercury (mm Hg). One atm is equal to 760 mm Hg, which is the atmospheric pressure at sea level. Typically, for respiration, other pressure values are discussed in relation to atmospheric pressure. Therefore, negative pressure is pressure lower than the atmospheric pressure, whereas positive pressure is pressure that it is greater than the atmospheric pressure. A pressure that is equal to the atmospheric pressure is expressed as zero. Intra-alveolar pressure is the pressure of the air within the alveoli, which changes during the different phases of breathing (Figure 22.16). Because the alveoli are connected to the atmosphere via the tubing of the airways (similar to the two- and one-liter containers in the example above), the interpulmonary pressure of the alveoli always equalizes with the atmospheric pressure.