NilsML/retriever_dataset · Datasets at Hugging Face

question stringlengths 14 399	distractor3 stringlengths 1 63	distractor1 stringlengths 1 57	distractor2 stringlengths 1 62	correct_answer stringlengths 1 67	support stringlengths 31 3.56k ⌀
What type of fossils are of organisms that lived over a wide area for a fairly short period of time and are used to determine the age of the rock it is in?	reference fossils	inventory fossils	rate fossils	index fossils	Fossils are used to determine the ages of rock layers. Index fossils are the most useful for this. Index fossils are of organisms that lived over a wide area. They lived for a fairly short period of time. An index fossil allows a scientist to determine the age of the rock it is in.
What term is defined as the preserved remains or traces of organisms that lived during earlier ages?	deposits	taxidermy	archaeology	fossils	Fossils are the preserved remains or traces of organisms that lived during earlier ages. Remains that become fossils are generally the hard parts of organisms—mainly bones, teeth, or shells. Traces include any evidence of life, such as footprints like the dinosaur footprint in Figure below . Fossils are like a window into the past. They provide direct evidence of what life was like long ago. A scientist who studies fossils to learn about the evolution of living things is called a paleontologist .
Which glands produce milk after the birth of offspring?	adrenal glands	Thyroid gland	Pituitary gland	mammary	All female mammals have mammary glands. Mammary glands are glands that produce milk after the birth of offspring. Producing milk for offspring is called lactation. The colt in Figure below is getting milk from its mother.
Reduction often involves the gain of hydrogen, the loss of oxygen, or the gain of what?	neutrons	mass	protons	electrons	Reduction often involves the gain of hydrogen, the loss of oxygen, or the gain of electrons.
What is a short band of tough connective tissue that connects bones together to form a joint?	cartilage	muscle tissue	a tendon	a ligament	Recall that a ligament is a short band of tough connective tissue that connects bones together to form a joint. Ligaments can get injured when a joint gets twisted or bends too far. The protein fibers that make up a ligament can get strained or torn, causing swelling and pain. Injuries to ligaments are called sprains . Ankle sprains are a common type of sprain.
When you burn wood into ash or burn a marshmallow to become brown and crispy, it is impossible to undo. this change is known as what?	physical change	carbon change	compounding change	chemical change	Yummy! S’mores are on the way! Did you ever toast marshmallows over a campfire? The sweet treats singe on the outside and melt on the inside. Both the fire and the toasted marshmallows are evidence of chemical changes. In the process of burning, the wood changes to ashes and gases, and the outside of the marshmallow turns brown and crispy. Neither the wood nor the marshmallows can change back to their original form. That’s because burning is a chemical change and chemical changes are often impossible to undo. In this unit, you’ll learn about many types of chemical changes, including how they occur and why you can’t live without them.
Which biomes are determined mainly by sunlight and concentrations of dissolved oxygen and nutrients in the water?	bacterial	viral	symbiotic	aquatic	Aquatic biomes are determined mainly by sunlight and concentrations of dissolved oxygen and nutrients in the water.
What is the moon's shadow's inner part called?	aurora	mullah	penumbra	umbra	The Moon’s shadow has two distinct parts. The umbra is the inner, cone-shaped part of the shadow. It is the part in which all of the light has been blocked. The penumbra is the outer part of Moon’s shadow. It is where the light is only partially blocked.
The earliest known mammal fossils are from which period?	Cretaceous Period	Tertiary	Mesosoic period	early jurassic	A key characteristic of synapsids is endothermy, rather than the ectothermy seen in most other vertebrates. The increased metabolic rate required to internally modify body temperature went hand in hand with changes to certain skeletal structures. The later synapsids, which had more evolved characteristics unique to mammals, possess cheeks for holding food and heterodont teeth, which are specialized for chewing, mechanically breaking down food to speed digestion and releasing the energy needed to produce heat. Chewing also requires the ability to chew and breathe at the same time, which is facilitated by the presence of a secondary palate. A secondary palate separates the area of the mouth where chewing occurs from the area above where respiration occurs, allowing breathing to proceed uninterrupted during chewing. A secondary palate is not found in pelycosaurs but is present in cynodonts and mammals. The jawbone also shows changes from early synapsids to later ones. The zygomatic arch, or cheekbone, is present in mammals and advanced therapsids such as cynodonts, but is not present in pelycosaurs. The presence of the zygomatic arch suggests the presence of the masseter muscle, which closes the jaw and functions in chewing. In the appendicular skeleton, the shoulder girdle of therian mammals is modified from that of other vertebrates in that it does not possess a procoracoid bone or an interclavicle, and the scapula is the dominant bone. Mammals evolved from therapsids in the late Triassic period, as the earliest known mammal fossils are from the early Jurassic period, some 205 million years ago. Early mammals were small, about the size of a small rodent. Mammals first began to diversify in the Mesozoic Era, from the Jurassic to the Cretaceous periods, although most of these mammals were extinct by the end of the Mesozoic. During the Cretaceous period, another radiation of mammals began and continued through the Cenozoic Era, about 65 million years ago.
Each parapodium has numerous chaetae, bristles made of what?	casein	ricin	lectin	chitin	null
What phylum includes sponges, which are aquatic invertebrates?	hymenoptera	chordata	mollusca	porifera	Sponges are aquatic invertebrates in Phylum Porifera. Sponges have specialized cells and an endoskeleton, but they lack tissues and body symmetry. Many live on coral reefs and have symbiotic relationships with other reef species.
Which are the three most important temperature scales?	thermoelectric , celsius , kelvin	temperatures , celsius , kelvin	Kelvin, celcius, richter	fahrenheit, celsius, kelvin	Temperature Scales Thermometers are used to measure temperature according to well-defined scales of measurement, which use pre-defined reference points to help compare quantities. The three most common temperature scales are the Fahrenheit, Celsius, and Kelvin scales. A temperature scale can be created by identifying two easily reproducible temperatures. The freezing and boiling temperatures of water at standard atmospheric pressure are commonly used. The Celsius scale (which replaced the slightly different centigrade scale) has the freezing point of water at point at.
What part of the body does caffeine stimulate?	large nervous system	autonomic nervous system	sympathetic nervous system	central nervous system	Some psychoactive drugs, such as caffeine, stimulate the central nervous system. They may make the user feel more alert. Some psychoactive drugs, such as alcohol, depress the central nervous system. They may make the user feel more relaxed. Still other psychoactive drugs, such as marijuana, are hallucinogenic drugs. They may make the user have altered sensations, perceptions, or thoughts.
An alpha particle, which is emitted during alpha decay, consists of two protons and what else?	two positrons	two electrons	two nuclei	two neutrons	A: Along with another electron, it can combine with an alpha particle to form a helium atom. An alpha particle, which is emitted during alpha decay, consists of two protons and two neutrons.
Melanin in skin is produced in response to exposure to what type of light?	infrared light	x rays	visible light	uv light	Intermediate Pituitary: Melanocyte-Stimulating Hormone The cells in the zone between the pituitary lobes secrete a hormone known as melanocyte-stimulating hormone (MSH) that is formed by cleavage of the pro-opiomelanocortin (POMC) precursor protein. Local production of MSH in the skin is responsible for melanin production in response to UV light exposure. The role of MSH made by the pituitary is more complicated. For instance, people with lighter skin generally have the same amount of MSH as people with darker skin. Nevertheless, this hormone is capable of darkening of the skin by inducing melanin production in the skin’s melanocytes. Women also show increased MSH production during pregnancy; in combination with estrogens, it can lead to darker skin pigmentation, especially the skin of the areolas and labia minora. Figure 17.11 is a summary of the pituitary hormones and their principal effects.
Protein molecules are made up of chains of small molecules made up of what kinds of acids?	rna acids	hydrochloric acids	mutation acids	amino acids	Proteins are biochemical compounds that contain oxygen, nitrogen, and sulfur in addition to carbon and hydrogen. Protein molecules consist of one or more chains of small molecules called amino acids.
Which element has the highest electronegativity value?	Barium	chlorine	magnesium	fluorine	The highest electronegativity value is for fluorine.
When small particles, such as clay and silt, are in mixed in water but do not disolve in the water, what state are they in?	sedimentation	mud	incomplete	suspension	Small particles, such as clay and silt, are carried in suspension . They are mixed throughout the water. These particles are not dissolved in the water.
When a person stands on the floor, his feet exert what on the surface?	resistance	acceleration	power	pressure	When a person stands on the floor, his feet exert pressure on the surface. That pressure is related to both the mass of the person and the surface area of his feet. If the person were holding a heavy object, the pressure would increase because of a greater force. Alternatively, if the person stands on his toes, the pressure also increases because of a decrease in the surface area.
Molds that grow on bread are from what kingdom?	pollen	animal	yeast	fungi	Do you see the organisms growing on the bread in Figure below ? They belong to the Kingdom Fungi. Molds growing on foods are some of the most common fungi in our everyday lives. These organisms may seem useless, gross, and costly. But fungi play very important roles in almost every terrestrial ecosystem on Earth.
What is defined as the change in the size of the population over time?	overpopulation	extinction	population density	population growth	Population growth is the change in the size of the population over time. An important factor in population growth is age-sex structure . This is the number of individuals of each sex and age in the population. The age-sex structure influences population growth. This is because younger people are more likely to reproduce, while older people have higher rates of dying.
The frequency of sound waves is measured in what, or the number of waves that pass a fixed point in a second?	watts	avis	Ohms	hertz	The frequency of sound waves is measured in hertz (Hz), or the number of waves that pass a fixed point in a second. Human beings can normally hear sounds with a frequency between about 20 Hz and 20,000 Hz. Sounds with frequencies below 20 hertz are called infrasound . Sounds with frequencies above 20,000 hertz are called ultrasound . Some other animals can hear sounds in the ultrasound range. For example, dogs can hear sounds with frequencies as high as 50,000 Hz. You may have seen special whistles that dogs but not people can hear. The whistles produce a sound with a frequency too high for the human ear to detect. Other animals can hear even higher-frequency sounds. Bats, for example, can hear sounds with frequencies higher than 100,000 Hz.
What are examples of parasitic athropods?	spiders and fleas	bees and wasps	crabs and clams	ticks and many mites	null
In a position-time graph, what does the slope of the line represent?	direction	position	time	velocity	In a position-time graph, the velocity of the moving object is represented by the slope, or steepness, of the graph line. If the graph line is horizontal, like the line after time = 5 seconds in Graph 2 in the Figure below , then the slope is zero and so is the velocity. The position of the object is not changing. The steeper the line is, the greater the slope of the line is and the faster the object’s motion is changing.
Salmon must do what when they migrate from freshwater to the ocean?	synthesize	regenerate	adapt	acclimatize	null
What occurs when two free radicals come in contact with each other?	cancellation	assimilation	radiation	termination	Termination occurs whenever two free radicals come in contact with one another (not shown). The two free electrons form a covalent bond and the free radical on each molecule no longer exists.
Despite the season, what aspect of constellations never change?	location	colors	size	patterns	The constellations stay the same night after night. The patterns of the stars never change. However, each night the constellations move across the sky. They move because Earth is spinning on its axis. The constellations also move with the seasons. This is because Earth revolves around the Sun. The constellations in the winter are different from those in the summer. For example, Orion is high up in the winter sky. In the summer, it's only up in the early morning.
What do you call electrons that form bonds with other elements in compounds and generally determine the properties of elements?	ionic electrons	isotopes	shell electrons	valence electrons	Other properties of the transition metals are unique. They are the only elements that may use electrons in the next to highest—as well as the highest—energy level as valence electrons. Valence electrons are the electrons that form bonds with other elements in compounds and that generally determine the properties of elements. Transition metals are unusual in having very similar properties even with different numbers of valence electrons. The transition metals also include the only elements that produce a magnetic field. Three of them have this property: iron (Fe), cobalt (Co), and nickel (Ni).
What is the members of the clade vertebrata known as?	lipids	invertebrates	grasses	vertebrates	Vertebrates are members of the clade Vertebrata. Vertebrates display the four characteristic features of the chordates; however, members of this group also share derived characteristics that distinguish them from invertebrate chordates. Vertebrata is named for the vertebral column, composed of vertebrae, a series of separate bones joined together as a backbone (Figure 29.7). In adult vertebrates, the vertebral column replaces the notochord, which is only seen in the embryonic stage.
What two ways do fruits mainly disperse seeds?	roots and decay	bees and water	birds and wind	animals and wind	Fruits are adapted to disperse seeds with the help of animals or the wind.
What helps maglev trains go very fast?	gravity	rollers	wheels	magnets	The futuristic-looking train in Figure below is called a maglev train. The word "maglev" stands for "magnetic levitation. " Magnets push the train upward so it hovers, or levitates, above the track without actually touching it. This eliminates most of the friction acting against the train when it moves. Other magnets pull the train forward along the track. Because of these magnets, the train can go very fast. It can fly over the countryside at speeds up to 480 kilometers (300 miles) per hour! What are magnets and how do they exert such force? In this lesson, you’ll find out.
What is the study of energy changes that occur during chemical reactions and during changes of state?	nuclear biology	nuclear chemistry	thermobiology	thermochemistry	Thermochemistry is the study of energy changes that occur during chemical reactions and during changes of state. When chemical reactions occur, some chemical bonds are broken, while new chemical bonds form. As a result of the rearrangement of atoms, the total chemical potential energy of the system either increases or decreases.
Hormones that share what usually perform the same function?	radiation class	temperature	glandular process	chemical class	null
A glacier is an example of h20 in which state of matter?	gas	stable	liquid	solid	The state of matter is a physical property of that matter. H 2 O can exist in three different states of matter. This glacier is obviously a solid state of H 2 O, floating in the liquid state. Why does the ice float on water? Which has a greater density, solid H 2 O or liquid H 2 O?.
Silver chloride can be used as an antidote for which kind of poisoning?	arsenic	the bends	carbon monoxide	mercury	Silver chloride is an important compound that is commonly used in the production of photographic film. It also has many other uses, such as an antidote for mercury poisoning, a component of pottery glazes, and a reference standard for electrochemistry setups. It can be produced according to the reaction shown above. Now we will practice use of mole ratios and stoichiometry to determine the amounts of products and reactants necessary in our reaction.
What do we call the microflora that aid in the digestion process?	tissue flora	stomach flora	digestive flora	intestinal flora	Elimination The final step in digestion is the elimination of undigested food content and waste products. The undigested food material enters the colon, where most of the water is reabsorbed. Recall that the colon is also home to the microflora called “intestinal flora” that aid in the digestion process. The semi-solid waste is moved through the colon by peristaltic movements of the muscle and is stored in the rectum. As the rectum expands in response to storage of fecal matter, it triggers the neural signals required to set up the urge to eliminate. The solid waste is eliminated through the anus using peristaltic movements of the rectum.
Nitrogen also is released to the environment by decaying organisms or decaying wastes. these wastes release nitrogen in the form of what?	hydroxide	sulfide	methane	ammonium	Nitrogen also is released to the environment by decaying organisms or decaying wastes. These wastes release nitrogen in the form of ammonium.
What requirement of the second circuit does the current that flows in the primary circuit depend on?	velocity of current	composition of current	accumulation of current	amount of current	The current that flows in the primary depends on how much current is required by the secondary circuit.
Mammalian sex determination is determined genetically by the presence of chromosomes identified by what letters?	y and z	a and b	rna and dna	x and y	Sex Determination Mammalian sex determination is determined genetically by the presence of X and Y chromosomes. Individuals homozygous for X (XX) are female and heterozygous individuals (XY) are male. The presence of a Y chromosome causes the development of male characteristics and its absence results in female characteristics. The XY system is also found in some insects and plants. Avian sex determination is dependent on the presence of Z and W chromosomes. Homozygous for Z (ZZ) results in a male and heterozygous (ZW) results in a female. The W appears to be essential in determining the sex of the individual, similar to the Y chromosome in mammals. Some fish, crustaceans, insects (such as butterflies and moths), and reptiles use this system. The sex of some species is not determined by genetics but by some aspect of the environment. Sex determination in some crocodiles and turtles, for example, is often dependent on the temperature during critical periods of egg development. This is referred to as environmental sex determination, or more specifically as temperature-dependent sex determination. In many turtles, cooler temperatures during egg incubation produce males and warm temperatures produce females. In some crocodiles, moderate temperatures produce males and both warm and cool temperatures produce females. In some species, sex is both genetic- and temperature-dependent. Individuals of some species change their sex during their lives, alternating between male and female. If the individual is female first, it is termed protogyny or “first female,” if it is male first, its termed protandry or “first male. ” Oysters, for example, are born male, grow, and become female and lay eggs; some oyster species change sex multiple times.
What kind of symmetry do most adult echinoderms possess?	spherical	asymmetry	bilateral	radial symmetry	null
What happens if cancer cells enter the blood stream?	they die	they enter the brain	they mutate	carried through body	As a tumor increases in size, it may harm normal tissues around it. Sometimes cancer cells break away from a tumor. If they enter the bloodstream, they are carried throughout the body. Then the cells may start growing in other tissues. This is usually how cancer spreads from one part of the body to another. Once this happens, cancer is very hard to stop.
Fires, mainly caused by what, are a natural disturbance in temperate grasslands?	cigarettes	campfires	humans	lightning	Fires, mainly caused by lightning, are a natural disturbance in temperate grasslands. When fire is suppressed in temperate grasslands, the vegetation eventually converts to scrub and dense forests. Often, the restoration or management of temperate grasslands requires the use of controlled burns to suppress the growth of trees and maintain the grasses.
What is the net force acting on an object when two equal forces are applied from opposite directions?	negative	homeostasis	sum	zero	When two forces act on an object in opposite directions, like the book on the table, the net force is equal to the difference between the two forces. In other words, one force is subtracted from the other to calculate the net force. If the opposing forces are equal in strength, the net force is zero. That’s what happens with the book on the table. The upward force minus the downward force equals zero (20 N up - 20 N down = 0 N). Because the forces on the book are balanced, the book remains on the table and doesn’t move.
Insects use what structures, located on the head, to smell and taste chemicals, and in some cases to hear sounds?	caripace	appendages	legs	antennae	The head has a pair of antennae. Insects use their antennae to smell and taste chemicals. Some insects can also use their antennae to hear sounds.
The carbon cycle includes photosynthesis, in which plants change what to organic compounds?	carbon monoxide	chemical dioxide	acid dioxide	carbon dioxide	The carbon cycle includes photosynthesis, in which plants change carbon dioxide to organic compounds. It also includes cellular respiration, in which living things “burn” organic compounds and release carbon dioxide. Rocks, fossil fuels, and the ocean are also part of the carbon cycle.
Nucleic acids are found in all living cells and also what?	bacteria	parasites	fungi	viruses	Nucleic acids are organic compounds that contain carbon, hydrogen, oxygen, nitrogen, and phosphorus. They are made of smaller units called nucleotides . Nucleic acids are named for the nucleus of the cell, where some of them are found. Nucleic acids are found not only in all living cells but also in viruses. Types of nucleic acids include deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) .
What is the gelatinous layer that is sandwiched between the epidermis and gastrodermis?	myelin sheath	plasmid	aqueous humor	the mesoglea	null
Mollusks can be divided into how many classes?	three	four	nine	seven	stages: trochophore and veliger. Sexual dimorphism is the predominant sexual strategy in this phylum. Mollusks can be divided into seven classes, each with distinct morphological characteristics.
Stars are lit by what reaction?	Coriolis effect	ionization	nuclear fission	nuclear fusion	The points of light in the night sky are stars that are balls of gas. They are lit by nuclear fusion.
What is the term for a partial degradation of glucose without the use of oxygen?	oxidation	segregation	condensation	fermentation	null
What is the term for the measurement of the amount of variation of species in a given area?	ecosystem	divergence	reproduction	biodiversity	Biodiversity is a measurement of the amount of variation of the species in a given area.
The radioactive gas radon and uv radiation are culprits in different types of what disease?	metabolic disease	diabetes	reproductive	cancer	UV radiation is the leading cause of skin cancer. The radioactive gas known as radon causes lung cancer.
What is used to show energy flow through the trophic levels?	inverted food chain	biome graph	food pyramid	pyramid ecosystem	Pyramid ecosystem modeling can also be used to show energy flow through the trophic levels. Notice that these numbers are the same as those used in the energy flow compartment diagram in Figure 46.8. Pyramids of energy are always upright, and an ecosystem without sufficient primary productivity cannot be supported. All types of ecological pyramids are useful for characterizing ecosystem structure. However, in the study of energy flow through the ecosystem, pyramids of energy are the most consistent and representative models of ecosystem structure (Figure 46.10).
Compared to a straight wire, a coiled wire has a stronger what?	gravitational field	horizontal field	proximate field	magnetic field	Any wire with current flowing through it has a magnetic field. However, the magnetic field around a coiled wire is stronger than the magnetic field around a straight wire. That’s because each turn of the wire in the coil has its own magnetic field. Adding more turns to the coil of wire increases the strength of the field. Increasing the amount of current flowing through the coil also increases the strength of the magnetic field.
The extrusive type of what rock cools rapidly from lava at the surface?	erythematous	crystalline	precipitous	igneous	Extrusive igneous rocks cool from lava rapidly at the surface. They have small crystals.
The burning of fossil fuels releases three major things - thermal energy, water vapor, and what pollutant?	carbon monoxide	aluminum	hydrogen	carbon dioxide	When fossil fuels burn, they release thermal energy, water vapor, and carbon dioxide. The thermal energy can be used to generate electricity or do other work. The carbon dioxide is released into the atmosphere and is a major cause of global climate change. The burning of fossil fuels also releases many pollutants into the air. Pollutants such as sulfur dioxide form acid rain, which kills living things and damages metals, stonework, and other materials. Pollutants such as nitrogen oxides cause smog, which is harmful to human health. Tiny particles, or particulates, released when fossil fuels burn also harm human health.
Ground collapse, associated with chambers of what substance, leads to formation of a caldera?	lava	molten	stone	magma	The cause of supervolcano eruptions is being debated. Enormous magma chambers are filled with super hot magma. This enormous eruption leaves a huge hole. The ground collapses and creates a caldera.
A habitat’s features are determined mainly by abiotic factors such as?	length	mixing and rainfall	oxygen and rainfall	temperature and rainfall	Another aspect of a species’ niche is its habitat. The habitat is the physical environment in which a species lives and to which it is adapted. A habitat’s features are determined mainly by abiotic factors such as temperature and rainfall. These factors also influence the traits of the organisms that live there.
Sulfuric acid conducts the charge in what kind of battery?	lithium ion	nickel-metal hydride	nickel cadmium	lead-acid cell	Figure 21.10 Artist’s conception of a lead-acid cell. Chemical reactions in a lead-acid cell separate charge, sending negative charge to the anode, which is connected to the lead plates. The lead oxide plates are connected to the positive or cathode terminal of the cell. Sulfuric acid conducts the charge as well as participating in the chemical reaction.
The pubis forms the anterior portion of what bone?	femur	labia	clavicle	hip bone	Pubis The pubis forms the anterior portion of the hip bone (see Figure 8.13). The enlarged medial portion of the pubis is the pubic body. Located superiorly on the pubic body is a small bump called the pubic tubercle. The superior pubic ramus is the segment of bone that passes laterally from the pubic body to join the ilium. The narrow ridge running along the superior margin of the superior pubic ramus is the pectineal line of the pubis. The pubic body is joined to the pubic body of the opposite hip bone by the pubic symphysis. Extending downward and laterally from the body is the inferior pubic ramus. The pubic arch is the bony structure formed by the pubic symphysis, and the bodies and inferior pubic rami of the adjacent pubic bones. The inferior pubic ramus extends downward to join the ischial ramus. Together, these form the single ischiopubic ramus, which extends from the pubic body to the ischial tuberosity. The inverted V-shape formed as the ischiopubic rami from both sides come together at the pubic symphysis is called the subpubic angle.
What is the general term for water that falls from clouds to earth’s surface, in forms that include snow and rain?	distillation	condensation	groundwater	precipitation	Precipitation is water that falls from clouds to Earth’s surface. Water droplets in clouds fall to Earth when they become too large to stay aloft. The water falls as rain if the air is warm. If the air is cold, the water may freeze and fall as snow, sleet, or hail. Most precipitation falls into the oceans. Some falls on land.
What are an important predators of mosquitoes, that can be used to control this pest?	dogs	deers	primates	dragonflies	Ladybugs also consume mites, scale insects and small caterpillars. The larvae of many hoverfly species also feed upon aphids, with one larva consuming up to fifty aphids a day, which is about 1,000 in its lifetime. They also eat fruit tree spider mites and small caterpillars. Dragonflies are important predators of mosquitoes, and can be used to control this pest. Parasitic insects include insects such as wasps and flies that lay their eggs on or in the body of an insect host, which is then used as a food for developing larvae. The host is ultimately killed. Caterpillars also tend to be one likely target of parasitic wasps.
Receptors for which hormones reside in the cytoplasm or nucleus?	non lipid-soluble hormones	cores - soluble hormones	organism - soluble hormones	lipid-soluble hormones	null
Heterotrophs get food by eating what?	sand	plants	similar organisms	other organisms	Protozoa are heterotrophs. Heterotrophs get food by eating other organisms. Some protozoa prey on bacteria. Some are parasites of animals. Others graze on algae. Still others are decomposers that break down dead organic matter.
What is the process called when liquid changes to gas, even though it has not become hot enough to boil?	transpiration	expiration	oxidation	evaporation	Evaporation explains why clothes dry on a clothesline. Evaporation is the process in which a liquid changes to a gas without becoming hot enough to boil. It occurs when individual liquid particles at the exposed surface of the liquid absorb just enough energy to overcome the force of attraction with other liquid particles. If the surface particles are moving in the right direction, they will pull away from the liquid and move into the air. This is illustrated in the Figure below .
How often do partial lunar eclipses occur?	once a year	6 times a year	2 times a year	twice a year	Partial lunar eclipses occur at least twice a year, but total lunar eclipses are less common. The Moon glows with a dull red coloring during a total lunar eclipse.
What are the trillions of bacteria living within the large intestine called?	microflora	intastinal flora	probiotic	bacteria flora	Bacterial Flora Most bacteria that enter the alimentary canal are killed by lysozyme, defensins, HCl, or protein-digesting enzymes. However, trillions of bacteria live within the large intestine and are referred to as the bacterial flora. Most of the more than 700 species of these bacteria are nonpathogenic commensal organisms that cause no harm as long as they stay in the gut lumen. In fact, many facilitate chemical digestion and absorption, and some synthesize certain vitamins, mainly biotin, pantothenic acid, and vitamin K. Some are linked to increased immune response. A refined system prevents these bacteria from crossing the mucosal barrier. First, peptidoglycan, a component of bacterial cell walls, activates the release of chemicals by the mucosa’s epithelial cells, which draft immune cells, especially dendritic cells, into the mucosa. Dendritic cells open the tight junctions between epithelial cells and extend probes into the lumen to evaluate the microbial antigens. The dendritic cells with antigens then travel to neighboring lymphoid follicles in the mucosa where T cells inspect for antigens. This process triggers an IgA-mediated response, if warranted, in the lumen that blocks the commensal organisms from infiltrating the mucosa and setting off a far greater, widespread systematic reaction.
What is the process by which rocks and other sediments are picked up by a glacier?	picking	pulling	freezing	plucking	Plucking is the process by which rocks and other sediments are picked up by a glacier. They freeze to the bottom of the glacier and are carried away by the flowing ice.
Genetic variation produced in sexual life cycles contributes to what process?	generation	deconstruction	maturity	evolution	13.4 Genetic variation produced in sexual life cycles contributes to evolution.
Animal claws, spines, and shells are examples of what strategy for survival?	display behavior	learned behavior	spontaneous mutation	defense mechanism	null
The jejunum is about 0.9 meters (3 feet) long (in life) and runs from the duodenum to the ileum. jejunum means “empty” in latin and supposedly was so named by the ancient greeks who noticed it was always what?	weeks at death	black at death	time.the at death	empty at death	In relaxed muscle, the myosin-binding site on actin is blocked by ________. titin b. troponin c. myoglobin d. tropomyosin 17. The cell membrane of a muscle fiber is called a ________. myofibril b. sarcolemma c. sarcoplasm d. myofilament.
Cellular innate defenses in vertebrates also involve natural killer what?	lipids	nerves	proteins	cells	null
Which construction material previously used in factories and in homes caused cancer?	Paints contains lead	Silica	Alkylphenols	asbestos	The past use of asbestos in factories and in homes. Asbestos is a very dangerous material, and it was used in many buildings ( Figure below ). Asbestos can cause cancer and other lung diseases. The use of asbestos is not allowed today.
What is the number waves that pass a fixed point in a given amount of time called?	wave tendency	combination frequency	heating frequency	wave frequency	Wave frequency is the number of waves that pass a fixed point in a given amount of time. Frequencies of electromagnetic waves range from thousands of waves per second to trillions of waves per second.
The outer ear, or ear canal, carries sound to the recessed protected what?	ear lobe	lungs	aorta	eardrum	The outer ear, or ear canal, carries sound to the recessed protected eardrum. The air column in the ear canal resonates and is partially responsible for the sensitivity of the ear to sounds in the 2000 to 5000 Hz range. The middle ear converts sound into mechanical vibrations and applies these vibrations to the cochlea. The lever system of the middle ear takes the force exerted on.
What sport involves people quickly finding destinations using polar coordinates?	mapping	patterning	sticking	orienteering	Polar coordinates are used in a sport called orienteering. People who do orienteering use a compass and a map with polar coordinates. Participants find their way along a course across wilderness terrain ( Figure below ). They move to various checkpoints along the course. The winner is the person who completes the course in the fastest time.
Almost all earthquakes occur at which place?	land boundaries	continental shelf	mountains	plate boundaries	Almost all earthquakes occur at plate boundaries. All types of plate boundaries have earthquakes. Convection within the Earth causes the plates to move. As the plates move, stresses build. When the stresses build too much, the rocks break. The break releases the energy that was stored in the rocks. The sudden release of energy creates an earthquake. During an earthquake the rocks usually move several centimeters or rarely as much as a few meters. Elastic rebound theory describes how earthquakes occur ( Figure below ).
Melting glaciers, rising temperatures and droughts are all impacts of what?	nature's natural cycle	sudden warming	air pollution	global warming	Melting glaciers, rising temperatures and droughts are all impacts of global warming. But how does global warming actually affect the oceans? The sea, it turns out, absorbs carbon dioxide emissions. The ocean acts like a giant sponge, absorbing carbon dioxide emissions from the air. And as we add more and more carbon dioxide to air by burning fossil fuels, the ocean is absorbing it. On one level, it's done us a big favor. Scientists say that we would be experiencing much more extreme climate change were it not for the ocean's ability to remove the heat-trapping gas. However, these emissions are causing the oceans to become more acidic. Changing pH levels threaten entire marine food webs, from coral reefs to salmon. See http://www. kqed. org/quest/radio/acidic-seas for additional information.
What parts of a human possess the highest concentration of thermoreceptors?	face and hair	hand and ears	hands and feet	face and ears	Thermoreceptors perceive sensations related to the temperature of objects. There are two basic categories of thermoreceptors: hot receptors and cold receptors. The highest concentration of thermoreceptors can be found in the face and ears.

What type of fossils are of organisms that lived over a wide area for a fairly short period of time and are used to determine the age of the rock it is in?

reference fossils

inventory fossils

rate fossils

index fossils

Fossils are used to determine the ages of rock layers. Index fossils are the most useful for this. Index fossils are of organisms that lived over a wide area. They lived for a fairly short period of time. An index fossil allows a scientist to determine the age of the rock it is in.

What term is defined as the preserved remains or traces of organisms that lived during earlier ages?

deposits

taxidermy

archaeology

fossils

Fossils are the preserved remains or traces of organisms that lived during earlier ages. Remains that become fossils are generally the hard parts of organisms—mainly bones, teeth, or shells. Traces include any evidence of life, such as footprints like the dinosaur footprint in Figure below . Fossils are like a window into the past. They provide direct evidence of what life was like long ago. A scientist who studies fossils to learn about the evolution of living things is called a paleontologist .

Which glands produce milk after the birth of offspring?

adrenal glands

Thyroid gland

Pituitary gland

mammary

All female mammals have mammary glands. Mammary glands are glands that produce milk after the birth of offspring. Producing milk for offspring is called lactation. The colt in Figure below is getting milk from its mother.

Reduction often involves the gain of hydrogen, the loss of oxygen, or the gain of what?

neutrons

mass

protons

electrons

Reduction often involves the gain of hydrogen, the loss of oxygen, or the gain of electrons.

What is a short band of tough connective tissue that connects bones together to form a joint?

cartilage

muscle tissue

a tendon

a ligament

Recall that a ligament is a short band of tough connective tissue that connects bones together to form a joint. Ligaments can get injured when a joint gets twisted or bends too far. The protein fibers that make up a ligament can get strained or torn, causing swelling and pain. Injuries to ligaments are called sprains . Ankle sprains are a common type of sprain.

When you burn wood into ash or burn a marshmallow to become brown and crispy, it is impossible to undo. this change is known as what?

physical change

carbon change

compounding change

chemical change

Yummy! S’mores are on the way! Did you ever toast marshmallows over a campfire? The sweet treats singe on the outside and melt on the inside. Both the fire and the toasted marshmallows are evidence of chemical changes. In the process of burning, the wood changes to ashes and gases, and the outside of the marshmallow turns brown and crispy. Neither the wood nor the marshmallows can change back to their original form. That’s because burning is a chemical change and chemical changes are often impossible to undo. In this unit, you’ll learn about many types of chemical changes, including how they occur and why you can’t live without them.

Which biomes are determined mainly by sunlight and concentrations of dissolved oxygen and nutrients in the water?

bacterial

viral

symbiotic

aquatic

Aquatic biomes are determined mainly by sunlight and concentrations of dissolved oxygen and nutrients in the water.

What is the moon's shadow's inner part called?

aurora

mullah

penumbra

umbra

The Moon’s shadow has two distinct parts. The umbra is the inner, cone-shaped part of the shadow. It is the part in which all of the light has been blocked. The penumbra is the outer part of Moon’s shadow. It is where the light is only partially blocked.

The earliest known mammal fossils are from which period?

Cretaceous Period

Tertiary

Mesosoic period

early jurassic

A key characteristic of synapsids is endothermy, rather than the ectothermy seen in most other vertebrates. The increased metabolic rate required to internally modify body temperature went hand in hand with changes to certain skeletal structures. The later synapsids, which had more evolved characteristics unique to mammals, possess cheeks for holding food and heterodont teeth, which are specialized for chewing, mechanically breaking down food to speed digestion and releasing the energy needed to produce heat. Chewing also requires the ability to chew and breathe at the same time, which is facilitated by the presence of a secondary palate. A secondary palate separates the area of the mouth where chewing occurs from the area above where respiration occurs, allowing breathing to proceed uninterrupted during chewing. A secondary palate is not found in pelycosaurs but is present in cynodonts and mammals. The jawbone also shows changes from early synapsids to later ones. The zygomatic arch, or cheekbone, is present in mammals and advanced therapsids such as cynodonts, but is not present in pelycosaurs. The presence of the zygomatic arch suggests the presence of the masseter muscle, which closes the jaw and functions in chewing. In the appendicular skeleton, the shoulder girdle of therian mammals is modified from that of other vertebrates in that it does not possess a procoracoid bone or an interclavicle, and the scapula is the dominant bone. Mammals evolved from therapsids in the late Triassic period, as the earliest known mammal fossils are from the early Jurassic period, some 205 million years ago. Early mammals were small, about the size of a small rodent. Mammals first began to diversify in the Mesozoic Era, from the Jurassic to the Cretaceous periods, although most of these mammals were extinct by the end of the Mesozoic. During the Cretaceous period, another radiation of mammals began and continued through the Cenozoic Era, about 65 million years ago.

Each parapodium has numerous chaetae, bristles made of what?

casein

ricin

lectin

chitin

null

What phylum includes sponges, which are aquatic invertebrates?

hymenoptera

chordata

mollusca

porifera

Sponges are aquatic invertebrates in Phylum Porifera. Sponges have specialized cells and an endoskeleton, but they lack tissues and body symmetry. Many live on coral reefs and have symbiotic relationships with other reef species.

Which are the three most important temperature scales?

thermoelectric , celsius , kelvin

temperatures , celsius , kelvin

Kelvin, celcius, richter

fahrenheit, celsius, kelvin

Temperature Scales Thermometers are used to measure temperature according to well-defined scales of measurement, which use pre-defined reference points to help compare quantities. The three most common temperature scales are the Fahrenheit, Celsius, and Kelvin scales. A temperature scale can be created by identifying two easily reproducible temperatures. The freezing and boiling temperatures of water at standard atmospheric pressure are commonly used. The Celsius scale (which replaced the slightly different centigrade scale) has the freezing point of water at point at.

What part of the body does caffeine stimulate?

large nervous system

autonomic nervous system

sympathetic nervous system

central nervous system

Some psychoactive drugs, such as caffeine, stimulate the central nervous system. They may make the user feel more alert. Some psychoactive drugs, such as alcohol, depress the central nervous system. They may make the user feel more relaxed. Still other psychoactive drugs, such as marijuana, are hallucinogenic drugs. They may make the user have altered sensations, perceptions, or thoughts.

An alpha particle, which is emitted during alpha decay, consists of two protons and what else?

two positrons

two electrons

two nuclei

two neutrons

A: Along with another electron, it can combine with an alpha particle to form a helium atom. An alpha particle, which is emitted during alpha decay, consists of two protons and two neutrons.

Melanin in skin is produced in response to exposure to what type of light?

infrared light

x rays

visible light

uv light

Intermediate Pituitary: Melanocyte-Stimulating Hormone The cells in the zone between the pituitary lobes secrete a hormone known as melanocyte-stimulating hormone (MSH) that is formed by cleavage of the pro-opiomelanocortin (POMC) precursor protein. Local production of MSH in the skin is responsible for melanin production in response to UV light exposure. The role of MSH made by the pituitary is more complicated. For instance, people with lighter skin generally have the same amount of MSH as people with darker skin. Nevertheless, this hormone is capable of darkening of the skin by inducing melanin production in the skin’s melanocytes. Women also show increased MSH production during pregnancy; in combination with estrogens, it can lead to darker skin pigmentation, especially the skin of the areolas and labia minora. Figure 17.11 is a summary of the pituitary hormones and their principal effects.

Protein molecules are made up of chains of small molecules made up of what kinds of acids?

rna acids

hydrochloric acids

mutation acids

amino acids

Proteins are biochemical compounds that contain oxygen, nitrogen, and sulfur in addition to carbon and hydrogen. Protein molecules consist of one or more chains of small molecules called amino acids.

Which element has the highest electronegativity value?

Barium

chlorine

magnesium

fluorine

The highest electronegativity value is for fluorine.

When small particles, such as clay and silt, are in mixed in water but do not disolve in the water, what state are they in?

sedimentation

mud

incomplete

suspension

Small particles, such as clay and silt, are carried in suspension . They are mixed throughout the water. These particles are not dissolved in the water.

When a person stands on the floor, his feet exert what on the surface?

resistance

acceleration

power

pressure

When a person stands on the floor, his feet exert pressure on the surface. That pressure is related to both the mass of the person and the surface area of his feet. If the person were holding a heavy object, the pressure would increase because of a greater force. Alternatively, if the person stands on his toes, the pressure also increases because of a decrease in the surface area.

Molds that grow on bread are from what kingdom?

pollen

animal

yeast

fungi

Do you see the organisms growing on the bread in Figure below ? They belong to the Kingdom Fungi. Molds growing on foods are some of the most common fungi in our everyday lives. These organisms may seem useless, gross, and costly. But fungi play very important roles in almost every terrestrial ecosystem on Earth.

What is defined as the change in the size of the population over time?

overpopulation

extinction

population density

population growth

Population growth is the change in the size of the population over time. An important factor in population growth is age-sex structure . This is the number of individuals of each sex and age in the population. The age-sex structure influences population growth. This is because younger people are more likely to reproduce, while older people have higher rates of dying.

The frequency of sound waves is measured in what, or the number of waves that pass a fixed point in a second?

watts

avis

Ohms

hertz

The frequency of sound waves is measured in hertz (Hz), or the number of waves that pass a fixed point in a second. Human beings can normally hear sounds with a frequency between about 20 Hz and 20,000 Hz. Sounds with frequencies below 20 hertz are called infrasound . Sounds with frequencies above 20,000 hertz are called ultrasound . Some other animals can hear sounds in the ultrasound range. For example, dogs can hear sounds with frequencies as high as 50,000 Hz. You may have seen special whistles that dogs but not people can hear. The whistles produce a sound with a frequency too high for the human ear to detect. Other animals can hear even higher-frequency sounds. Bats, for example, can hear sounds with frequencies higher than 100,000 Hz.

What are examples of parasitic athropods?

spiders and fleas

bees and wasps

crabs and clams

ticks and many mites

null

In a position-time graph, what does the slope of the line represent?

direction

position

time

velocity

In a position-time graph, the velocity of the moving object is represented by the slope, or steepness, of the graph line. If the graph line is horizontal, like the line after time = 5 seconds in Graph 2 in the Figure below , then the slope is zero and so is the velocity. The position of the object is not changing. The steeper the line is, the greater the slope of the line is and the faster the object’s motion is changing.

Salmon must do what when they migrate from freshwater to the ocean?

synthesize

regenerate

adapt

acclimatize

null

What occurs when two free radicals come in contact with each other?

cancellation

assimilation

radiation

termination

Termination occurs whenever two free radicals come in contact with one another (not shown). The two free electrons form a covalent bond and the free radical on each molecule no longer exists.

Despite the season, what aspect of constellations never change?

location

colors

size

patterns

The constellations stay the same night after night. The patterns of the stars never change. However, each night the constellations move across the sky. They move because Earth is spinning on its axis. The constellations also move with the seasons. This is because Earth revolves around the Sun. The constellations in the winter are different from those in the summer. For example, Orion is high up in the winter sky. In the summer, it's only up in the early morning.

What do you call electrons that form bonds with other elements in compounds and generally determine the properties of elements?

ionic electrons

isotopes

shell electrons

valence electrons

Other properties of the transition metals are unique. They are the only elements that may use electrons in the next to highest—as well as the highest—energy level as valence electrons. Valence electrons are the electrons that form bonds with other elements in compounds and that generally determine the properties of elements. Transition metals are unusual in having very similar properties even with different numbers of valence electrons. The transition metals also include the only elements that produce a magnetic field. Three of them have this property: iron (Fe), cobalt (Co), and nickel (Ni).

What is the members of the clade vertebrata known as?

lipids

invertebrates

grasses

vertebrates

Vertebrates are members of the clade Vertebrata. Vertebrates display the four characteristic features of the chordates; however, members of this group also share derived characteristics that distinguish them from invertebrate chordates. Vertebrata is named for the vertebral column, composed of vertebrae, a series of separate bones joined together as a backbone (Figure 29.7). In adult vertebrates, the vertebral column replaces the notochord, which is only seen in the embryonic stage.

What two ways do fruits mainly disperse seeds?

roots and decay

bees and water

birds and wind

animals and wind

Fruits are adapted to disperse seeds with the help of animals or the wind.

What helps maglev trains go very fast?

gravity

rollers

wheels

magnets

The futuristic-looking train in Figure below is called a maglev train. The word "maglev" stands for "magnetic levitation. " Magnets push the train upward so it hovers, or levitates, above the track without actually touching it. This eliminates most of the friction acting against the train when it moves. Other magnets pull the train forward along the track. Because of these magnets, the train can go very fast. It can fly over the countryside at speeds up to 480 kilometers (300 miles) per hour! What are magnets and how do they exert such force? In this lesson, you’ll find out.

What is the study of energy changes that occur during chemical reactions and during changes of state?

nuclear biology

nuclear chemistry

thermobiology

thermochemistry

Thermochemistry is the study of energy changes that occur during chemical reactions and during changes of state. When chemical reactions occur, some chemical bonds are broken, while new chemical bonds form. As a result of the rearrangement of atoms, the total chemical potential energy of the system either increases or decreases.

Hormones that share what usually perform the same function?

radiation class

temperature

glandular process

chemical class

null

A glacier is an example of h20 in which state of matter?

gas

stable

liquid

solid

The state of matter is a physical property of that matter. H 2 O can exist in three different states of matter. This glacier is obviously a solid state of H 2 O, floating in the liquid state. Why does the ice float on water? Which has a greater density, solid H 2 O or liquid H 2 O?.

Silver chloride can be used as an antidote for which kind of poisoning?

arsenic

the bends

carbon monoxide

mercury

Silver chloride is an important compound that is commonly used in the production of photographic film. It also has many other uses, such as an antidote for mercury poisoning, a component of pottery glazes, and a reference standard for electrochemistry setups. It can be produced according to the reaction shown above. Now we will practice use of mole ratios and stoichiometry to determine the amounts of products and reactants necessary in our reaction.

What do we call the microflora that aid in the digestion process?

tissue flora

stomach flora

digestive flora

intestinal flora

Elimination The final step in digestion is the elimination of undigested food content and waste products. The undigested food material enters the colon, where most of the water is reabsorbed. Recall that the colon is also home to the microflora called “intestinal flora” that aid in the digestion process. The semi-solid waste is moved through the colon by peristaltic movements of the muscle and is stored in the rectum. As the rectum expands in response to storage of fecal matter, it triggers the neural signals required to set up the urge to eliminate. The solid waste is eliminated through the anus using peristaltic movements of the rectum.

Nitrogen also is released to the environment by decaying organisms or decaying wastes. these wastes release nitrogen in the form of what?

hydroxide

sulfide

methane

ammonium

Nitrogen also is released to the environment by decaying organisms or decaying wastes. These wastes release nitrogen in the form of ammonium.

What requirement of the second circuit does the current that flows in the primary circuit depend on?

velocity of current

composition of current

accumulation of current

amount of current

The current that flows in the primary depends on how much current is required by the secondary circuit.

Mammalian sex determination is determined genetically by the presence of chromosomes identified by what letters?

y and z

a and b

rna and dna

x and y

Sex Determination Mammalian sex determination is determined genetically by the presence of X and Y chromosomes. Individuals homozygous for X (XX) are female and heterozygous individuals (XY) are male. The presence of a Y chromosome causes the development of male characteristics and its absence results in female characteristics. The XY system is also found in some insects and plants. Avian sex determination is dependent on the presence of Z and W chromosomes. Homozygous for Z (ZZ) results in a male and heterozygous (ZW) results in a female. The W appears to be essential in determining the sex of the individual, similar to the Y chromosome in mammals. Some fish, crustaceans, insects (such as butterflies and moths), and reptiles use this system. The sex of some species is not determined by genetics but by some aspect of the environment. Sex determination in some crocodiles and turtles, for example, is often dependent on the temperature during critical periods of egg development. This is referred to as environmental sex determination, or more specifically as temperature-dependent sex determination. In many turtles, cooler temperatures during egg incubation produce males and warm temperatures produce females. In some crocodiles, moderate temperatures produce males and both warm and cool temperatures produce females. In some species, sex is both genetic- and temperature-dependent. Individuals of some species change their sex during their lives, alternating between male and female. If the individual is female first, it is termed protogyny or “first female,” if it is male first, its termed protandry or “first male. ” Oysters, for example, are born male, grow, and become female and lay eggs; some oyster species change sex multiple times.

What kind of symmetry do most adult echinoderms possess?

spherical

asymmetry

bilateral

radial symmetry

null

What happens if cancer cells enter the blood stream?

they die

they enter the brain

they mutate

carried through body

As a tumor increases in size, it may harm normal tissues around it. Sometimes cancer cells break away from a tumor. If they enter the bloodstream, they are carried throughout the body. Then the cells may start growing in other tissues. This is usually how cancer spreads from one part of the body to another. Once this happens, cancer is very hard to stop.

Fires, mainly caused by what, are a natural disturbance in temperate grasslands?

cigarettes

campfires

humans

lightning

Fires, mainly caused by lightning, are a natural disturbance in temperate grasslands. When fire is suppressed in temperate grasslands, the vegetation eventually converts to scrub and dense forests. Often, the restoration or management of temperate grasslands requires the use of controlled burns to suppress the growth of trees and maintain the grasses.

What is the net force acting on an object when two equal forces are applied from opposite directions?

negative

homeostasis

sum

zero

When two forces act on an object in opposite directions, like the book on the table, the net force is equal to the difference between the two forces. In other words, one force is subtracted from the other to calculate the net force. If the opposing forces are equal in strength, the net force is zero. That’s what happens with the book on the table. The upward force minus the downward force equals zero (20 N up - 20 N down = 0 N). Because the forces on the book are balanced, the book remains on the table and doesn’t move.

Insects use what structures, located on the head, to smell and taste chemicals, and in some cases to hear sounds?

caripace

appendages

legs

antennae

The head has a pair of antennae. Insects use their antennae to smell and taste chemicals. Some insects can also use their antennae to hear sounds.

The carbon cycle includes photosynthesis, in which plants change what to organic compounds?

carbon monoxide

chemical dioxide

acid dioxide

carbon dioxide

The carbon cycle includes photosynthesis, in which plants change carbon dioxide to organic compounds. It also includes cellular respiration, in which living things “burn” organic compounds and release carbon dioxide. Rocks, fossil fuels, and the ocean are also part of the carbon cycle.

Nucleic acids are found in all living cells and also what?

bacteria

parasites

fungi

viruses

Nucleic acids are organic compounds that contain carbon, hydrogen, oxygen, nitrogen, and phosphorus. They are made of smaller units called nucleotides . Nucleic acids are named for the nucleus of the cell, where some of them are found. Nucleic acids are found not only in all living cells but also in viruses. Types of nucleic acids include deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) .

What is the gelatinous layer that is sandwiched between the epidermis and gastrodermis?

myelin sheath

plasmid

aqueous humor

the mesoglea

null

Mollusks can be divided into how many classes?

three

four

nine

seven

stages: trochophore and veliger. Sexual dimorphism is the predominant sexual strategy in this phylum. Mollusks can be divided into seven classes, each with distinct morphological characteristics.

Stars are lit by what reaction?

Coriolis effect

ionization

nuclear fission

nuclear fusion

The points of light in the night sky are stars that are balls of gas. They are lit by nuclear fusion.

What is the term for a partial degradation of glucose without the use of oxygen?

oxidation

segregation

condensation

fermentation

null

What is the term for the measurement of the amount of variation of species in a given area?

ecosystem

divergence

reproduction

biodiversity

Biodiversity is a measurement of the amount of variation of the species in a given area.

The radioactive gas radon and uv radiation are culprits in different types of what disease?

metabolic disease

diabetes

reproductive

cancer

UV radiation is the leading cause of skin cancer. The radioactive gas known as radon causes lung cancer.

What is used to show energy flow through the trophic levels?

inverted food chain

biome graph

food pyramid

pyramid ecosystem

Pyramid ecosystem modeling can also be used to show energy flow through the trophic levels. Notice that these numbers are the same as those used in the energy flow compartment diagram in Figure 46.8. Pyramids of energy are always upright, and an ecosystem without sufficient primary productivity cannot be supported. All types of ecological pyramids are useful for characterizing ecosystem structure. However, in the study of energy flow through the ecosystem, pyramids of energy are the most consistent and representative models of ecosystem structure (Figure 46.10).

Compared to a straight wire, a coiled wire has a stronger what?

gravitational field

horizontal field

proximate field

magnetic field

Any wire with current flowing through it has a magnetic field. However, the magnetic field around a coiled wire is stronger than the magnetic field around a straight wire. That’s because each turn of the wire in the coil has its own magnetic field. Adding more turns to the coil of wire increases the strength of the field. Increasing the amount of current flowing through the coil also increases the strength of the magnetic field.

The extrusive type of what rock cools rapidly from lava at the surface?

erythematous

crystalline

precipitous

igneous

Extrusive igneous rocks cool from lava rapidly at the surface. They have small crystals.

The burning of fossil fuels releases three major things - thermal energy, water vapor, and what pollutant?

carbon monoxide

aluminum

hydrogen

carbon dioxide

When fossil fuels burn, they release thermal energy, water vapor, and carbon dioxide. The thermal energy can be used to generate electricity or do other work. The carbon dioxide is released into the atmosphere and is a major cause of global climate change. The burning of fossil fuels also releases many pollutants into the air. Pollutants such as sulfur dioxide form acid rain, which kills living things and damages metals, stonework, and other materials. Pollutants such as nitrogen oxides cause smog, which is harmful to human health. Tiny particles, or particulates, released when fossil fuels burn also harm human health.

Ground collapse, associated with chambers of what substance, leads to formation of a caldera?

lava

molten

stone

magma

The cause of supervolcano eruptions is being debated. Enormous magma chambers are filled with super hot magma. This enormous eruption leaves a huge hole. The ground collapses and creates a caldera.

A habitat’s features are determined mainly by abiotic factors such as?

length

mixing and rainfall

oxygen and rainfall

temperature and rainfall

Another aspect of a species’ niche is its habitat. The habitat is the physical environment in which a species lives and to which it is adapted. A habitat’s features are determined mainly by abiotic factors such as temperature and rainfall. These factors also influence the traits of the organisms that live there.

Sulfuric acid conducts the charge in what kind of battery?

lithium ion

nickel-metal hydride

nickel cadmium

lead-acid cell

Figure 21.10 Artist’s conception of a lead-acid cell. Chemical reactions in a lead-acid cell separate charge, sending negative charge to the anode, which is connected to the lead plates. The lead oxide plates are connected to the positive or cathode terminal of the cell. Sulfuric acid conducts the charge as well as participating in the chemical reaction.

The pubis forms the anterior portion of what bone?

femur

labia

clavicle

hip bone

Pubis The pubis forms the anterior portion of the hip bone (see Figure 8.13). The enlarged medial portion of the pubis is the pubic body. Located superiorly on the pubic body is a small bump called the pubic tubercle. The superior pubic ramus is the segment of bone that passes laterally from the pubic body to join the ilium. The narrow ridge running along the superior margin of the superior pubic ramus is the pectineal line of the pubis. The pubic body is joined to the pubic body of the opposite hip bone by the pubic symphysis. Extending downward and laterally from the body is the inferior pubic ramus. The pubic arch is the bony structure formed by the pubic symphysis, and the bodies and inferior pubic rami of the adjacent pubic bones. The inferior pubic ramus extends downward to join the ischial ramus. Together, these form the single ischiopubic ramus, which extends from the pubic body to the ischial tuberosity. The inverted V-shape formed as the ischiopubic rami from both sides come together at the pubic symphysis is called the subpubic angle.

What is the general term for water that falls from clouds to earth’s surface, in forms that include snow and rain?

distillation

condensation

groundwater

precipitation

Precipitation is water that falls from clouds to Earth’s surface. Water droplets in clouds fall to Earth when they become too large to stay aloft. The water falls as rain if the air is warm. If the air is cold, the water may freeze and fall as snow, sleet, or hail. Most precipitation falls into the oceans. Some falls on land.

What are an important predators of mosquitoes, that can be used to control this pest?

dogs

deers

primates

dragonflies

Ladybugs also consume mites, scale insects and small caterpillars. The larvae of many hoverfly species also feed upon aphids, with one larva consuming up to fifty aphids a day, which is about 1,000 in its lifetime. They also eat fruit tree spider mites and small caterpillars. Dragonflies are important predators of mosquitoes, and can be used to control this pest. Parasitic insects include insects such as wasps and flies that lay their eggs on or in the body of an insect host, which is then used as a food for developing larvae. The host is ultimately killed. Caterpillars also tend to be one likely target of parasitic wasps.

Receptors for which hormones reside in the cytoplasm or nucleus?

non lipid-soluble hormones

cores - soluble hormones

organism - soluble hormones

lipid-soluble hormones

null

Heterotrophs get food by eating what?

sand

plants

similar organisms

other organisms

Protozoa are heterotrophs. Heterotrophs get food by eating other organisms. Some protozoa prey on bacteria. Some are parasites of animals. Others graze on algae. Still others are decomposers that break down dead organic matter.

What is the process called when liquid changes to gas, even though it has not become hot enough to boil?

transpiration

expiration

oxidation

evaporation

Evaporation explains why clothes dry on a clothesline. Evaporation is the process in which a liquid changes to a gas without becoming hot enough to boil. It occurs when individual liquid particles at the exposed surface of the liquid absorb just enough energy to overcome the force of attraction with other liquid particles. If the surface particles are moving in the right direction, they will pull away from the liquid and move into the air. This is illustrated in the Figure below .

How often do partial lunar eclipses occur?

once a year

6 times a year

2 times a year

twice a year

Partial lunar eclipses occur at least twice a year, but total lunar eclipses are less common. The Moon glows with a dull red coloring during a total lunar eclipse.

What are the trillions of bacteria living within the large intestine called?

microflora

intastinal flora

probiotic

bacteria flora

Bacterial Flora Most bacteria that enter the alimentary canal are killed by lysozyme, defensins, HCl, or protein-digesting enzymes. However, trillions of bacteria live within the large intestine and are referred to as the bacterial flora. Most of the more than 700 species of these bacteria are nonpathogenic commensal organisms that cause no harm as long as they stay in the gut lumen. In fact, many facilitate chemical digestion and absorption, and some synthesize certain vitamins, mainly biotin, pantothenic acid, and vitamin K. Some are linked to increased immune response. A refined system prevents these bacteria from crossing the mucosal barrier. First, peptidoglycan, a component of bacterial cell walls, activates the release of chemicals by the mucosa’s epithelial cells, which draft immune cells, especially dendritic cells, into the mucosa. Dendritic cells open the tight junctions between epithelial cells and extend probes into the lumen to evaluate the microbial antigens. The dendritic cells with antigens then travel to neighboring lymphoid follicles in the mucosa where T cells inspect for antigens. This process triggers an IgA-mediated response, if warranted, in the lumen that blocks the commensal organisms from infiltrating the mucosa and setting off a far greater, widespread systematic reaction.

What is the process by which rocks and other sediments are picked up by a glacier?

picking

pulling

freezing

plucking

Plucking is the process by which rocks and other sediments are picked up by a glacier. They freeze to the bottom of the glacier and are carried away by the flowing ice.

Genetic variation produced in sexual life cycles contributes to what process?

generation

deconstruction

maturity

evolution

13.4 Genetic variation produced in sexual life cycles contributes to evolution.

Animal claws, spines, and shells are examples of what strategy for survival?

display behavior

learned behavior

spontaneous mutation

defense mechanism

null

The jejunum is about 0.9 meters (3 feet) long (in life) and runs from the duodenum to the ileum. jejunum means “empty” in latin and supposedly was so named by the ancient greeks who noticed it was always what?

weeks at death

black at death

time.the at death

empty at death

In relaxed muscle, the myosin-binding site on actin is blocked by ________. titin b. troponin c. myoglobin d. tropomyosin 17. The cell membrane of a muscle fiber is called a ________. myofibril b. sarcolemma c. sarcoplasm d. myofilament.

Cellular innate defenses in vertebrates also involve natural killer what?

lipids

nerves

proteins

cells

null

Which construction material previously used in factories and in homes caused cancer?

Paints contains lead

Silica

Alkylphenols

asbestos

The past use of asbestos in factories and in homes. Asbestos is a very dangerous material, and it was used in many buildings ( Figure below ). Asbestos can cause cancer and other lung diseases. The use of asbestos is not allowed today.

What is the number waves that pass a fixed point in a given amount of time called?

wave tendency

combination frequency

heating frequency

wave frequency

Wave frequency is the number of waves that pass a fixed point in a given amount of time. Frequencies of electromagnetic waves range from thousands of waves per second to trillions of waves per second.

The outer ear, or ear canal, carries sound to the recessed protected what?

ear lobe

lungs

aorta

eardrum

The outer ear, or ear canal, carries sound to the recessed protected eardrum. The air column in the ear canal resonates and is partially responsible for the sensitivity of the ear to sounds in the 2000 to 5000 Hz range. The middle ear converts sound into mechanical vibrations and applies these vibrations to the cochlea. The lever system of the middle ear takes the force exerted on.

What sport involves people quickly finding destinations using polar coordinates?

mapping

patterning

sticking

orienteering

Polar coordinates are used in a sport called orienteering. People who do orienteering use a compass and a map with polar coordinates. Participants find their way along a course across wilderness terrain ( Figure below ). They move to various checkpoints along the course. The winner is the person who completes the course in the fastest time.

Almost all earthquakes occur at which place?

land boundaries

continental shelf

mountains

plate boundaries

Almost all earthquakes occur at plate boundaries. All types of plate boundaries have earthquakes. Convection within the Earth causes the plates to move. As the plates move, stresses build. When the stresses build too much, the rocks break. The break releases the energy that was stored in the rocks. The sudden release of energy creates an earthquake. During an earthquake the rocks usually move several centimeters or rarely as much as a few meters. Elastic rebound theory describes how earthquakes occur ( Figure below ).

Melting glaciers, rising temperatures and droughts are all impacts of what?

nature's natural cycle

sudden warming

air pollution

global warming

Melting glaciers, rising temperatures and droughts are all impacts of global warming. But how does global warming actually affect the oceans? The sea, it turns out, absorbs carbon dioxide emissions. The ocean acts like a giant sponge, absorbing carbon dioxide emissions from the air. And as we add more and more carbon dioxide to air by burning fossil fuels, the ocean is absorbing it. On one level, it's done us a big favor. Scientists say that we would be experiencing much more extreme climate change were it not for the ocean's ability to remove the heat-trapping gas. However, these emissions are causing the oceans to become more acidic. Changing pH levels threaten entire marine food webs, from coral reefs to salmon. See http://www. kqed. org/quest/radio/acidic-seas for additional information.

What parts of a human possess the highest concentration of thermoreceptors?

face and hair

hand and ears

hands and feet

face and ears

Thermoreceptors perceive sensations related to the temperature of objects. There are two basic categories of thermoreceptors: hot receptors and cold receptors. The highest concentration of thermoreceptors can be found in the face and ears.