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When animals get rid of their gaseous waste, what is exhaled through their mouth and nose? | incandescent light | oxygen | preventing | carbon dioxide | biology | 1 |
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What is another name for composite volcanos? | raise sea levels | plates | fault lines | stratovolcanoes | Composite volcanoes are also called stratovolcanoes. This is because they are formed by alternating layers (strata) of magma and ash ( Figure below ). The magma that creates composite volcanoes tends to be thick. The steep sides form because the lava cannot flow too far from the vent. The thick magma may also create explosive eruptions. Ash and pyroclasts erupt into the air. Much of this material falls back down near the vent. This creates the steep sides of stratovolcanoes. The composition of magma that erupts at composite volcanoes is usually felsic (rhyolite) or intermediate (andesite). | geography | 2 |
Fossil records support the idea that periods of little change may be interrupted by bursts of rapid change, an evolutionary model contrasted by what? | carotid | frontal bone | hamstring | gradualism | When geologic and climatic conditions are changing, evolution may occur more quickly. Thus, long periods of little change may be interrupted by bursts of rapid change. This model of the timing of evolution is called punctuated equilibrium . It is better supported by the fossil record than is gradualism. | biology | 0 |
What type of winds occur when air is forced over a mountain range? | 6 times a year | 23 million | whole earth | chinook winds | Chinook winds ( Figure below ) occur when air is forced over a mountain range. Warm air rises over the Sierra Nevada in California, for example, because it is pushed eastward by the westerly winds. The air cools as it rises and precipitates. The air is now dry. It sinks down the far side of the mountains and may create strong winds. These Chinook winds are relatively warm. If there is snow, the winds may melt it quickly. The dry sinking air creates a rainshadow effect . Rainshadow effect is responsible for many of the world's deserts. | geography | 0 |
What do clouds trap into the atmosphere at night? | smog | atoms materials | Explosive bang | heat | Clouds block sunlight in the day. Clouds trap heat in the atmosphere at night. | physics | 1 |
A nerve cell that carries messages is called a? | platelet | mitochondria | a common gene | neuron | The nervous system is made up of nerves. A nerve is a bundle of nerve cells. A nerve cell that carries messages is called a neuron. The messages carried by neurons are called nerve impulses. | biology | 2 |
What group of animals are the largest arthropods? | graphic | marine biologists | specialized arteries | insects | There are several traits shared by all arthropods. Arthropods have a complete digestive system. They also have a circulatory system and a nervous system. In addition, they have special organs for breathing and excreting wastes. Other traits of arthropods include:. | biology | 0 |
What term describes a collection of similar cells that had a common embryonic origin? | rna analysis | organ-level organization | plasma | tissue | Complex Tissue Structure A hallmark trait of animals is specialized structures that are differentiated to perform unique functions. As multicellular organisms, most animals develop specialized cells that group together into tissues with specialized functions. A tissue is a collection of similar cells that had a common embryonic origin. There are four main types of animal tissues: nervous, muscle, connective, and epithelial. Nervous tissue contains neurons, or nerve cells, which transmit nerve impulses. Muscle tissue contracts to cause all types of body movement from locomotion of the organism to movements within the body itself. Animals also have specialized connective tissues that provide many functions, including transport and structural support. Examples of connective tissues include blood and bone. Connective tissue is comprised of cells separated by extracellular material made of organic and inorganic materials, such as the protein and mineral deposits of bone. Epithelial tissue covers the internal and external surfaces of organs inside the animal body and the external surface of the body of the organism. | biology | 3 |
Most biochemical molecules are macromolecules, meaning that they are what? | abnormal | white blood cell | very small | very large | Most biochemical molecules are macromolecules, meaning that they are very large. Some contain thousands of monomer molecules. | biology | 1 |
The name of a spinal cord region corresponds to the level at which spinal nerves pass through the what? | overpopulation | the mucus | notochord | intervertebral foramina | The Spinal Cord The description of the CNS is concentrated on the structures of the brain, but the spinal cord is another major organ of the system. Whereas the brain develops out of expansions of the neural tube into primary and then secondary vesicles, the spinal cord maintains the tube structure and is only specialized into certain regions. As the spinal cord continues to develop in the newborn, anatomical features mark its surface. The anterior midline is marked by the anterior median fissure, and the posterior midline is marked by the posterior median sulcus. Axons enter the posterior side through the dorsal (posterior) nerve root, which marks the posterolateral sulcus on either side. The axons emerging from the anterior side do so through the ventral (anterior) nerve root. Note that it is common to see the terms dorsal (dorsal = “back”) and ventral (ventral = “belly”) used interchangeably with posterior and anterior, particularly in reference to nerves and the structures of the spinal cord. You should learn to be comfortable with both. On the whole, the posterior regions are responsible for sensory functions and the anterior regions are associated with motor functions. This comes from the initial development of the spinal cord, which is divided into the basal plate and the alar plate. The basal plate is closest to the ventral midline of the neural tube, which will become the anterior face of the spinal cord and gives rise to motor neurons. The alar plate is on the dorsal side of the neural tube and gives rise to neurons that will receive sensory input from the periphery. The length of the spinal cord is divided into regions that correspond to the regions of the vertebral column. The name of a spinal cord region corresponds to the level at which spinal nerves pass through the intervertebral foramina. Immediately adjacent to the brain stem is the cervical region, followed by the thoracic, then the lumbar, and finally the sacral region. The spinal cord is not the full length of the vertebral column because the spinal cord does not grow significantly longer after the first or second year, but the skeleton continues to grow. The nerves that emerge from the spinal cord pass through the intervertebral formina at the respective levels. As the vertebral column grows, these nerves grow with it and result in a long bundle of nerves that resembles a horse’s tail and is named the cauda equina. The sacral spinal cord is at the level of the upper lumbar vertebral bones. The spinal nerves extend from their various levels to the proper level of the vertebral column. | biology | 3 |
Tests for levels of what in blood allow a diabetic patient to regulate how much insulin to administer? | the photosynthesizer | red blood cells | pumps | glucose | Laboratory testing has come to the local drug store or grocery store because of developments in chemistry. You can test your blood glucose using a simple portable device that runs a chemical test on the blood sample and tells you how much glucose is present, allowing a diabetic patient to regulate how much insulin to administer (chemistry is also used to produce the insulin and the disposable syringe that administers the drug). | biology | 3 |
The process of breaking down food into nutrients is known as __________ | it starts over | adaptive immunity | apoptosis | digestion | As food is pushed through the GI tract by peristalsis, it undergoes digestion. Digestion is the process of breaking down food into nutrients. There are two types of digestion: mechanical digestion and chemical digestion. | biology | 2 |
Reasoning can be broken down into two categories: deduction and? | the contractile vacuole | flue | elastic potential energy | induction | Any useful hypothesis will allow predictions based on reasoning. Reasoning can be broken down into two categories: deduction and induction. Most reasoning in science is formed through induction. | physics | 2 |
What are used to make maps of the moon and other planets? | surface | oil spill | blue | imaging satellites | Astronomers use imaging satellites to study and make maps of the Moon and other planets. | geography | 0 |
What term describes how closely packed the particles of matter are? | initiation | range | thermal images | density | Density is an important physical property of matter. It reflects how closely packed the particles of matter are. When particles are packed together more tightly, matter has greater density. Differences in density of matter explain many phenomena, not just why helium balloons rise. For example, differences in density of cool and warm ocean water explain why currents such as the Gulf Stream flow through the oceans. You can see a colorful demonstration of substances with different densities at this URL:. | physics | 1 |
Populations of viruses do not grow through cell division because they? | blister | clumps | tubules | are not cells | Populations of viruses do not grow through cell division because they are not cells. Instead, they use the machinery and metabolism of a host cell to produce new copies of themselves. After infecting a host cell, a virion uses the cell’s ribosomes, enzymes, ATP, and other components to replicate. Viruses vary in how they do this. For example:. | biology | 0 |
What is likely to happen to a parasite if it kills its host? | it mutates | mirroring | reproductive system | it dies | Some parasites kill their host, but most do not. It’s easy to see why. If a parasite kills its host, the parasite is also likely to die. Instead, parasites usually cause relatively minor damage to their host. | biology | 2 |
What is a type of solid that lacks an ordered internal structure? | further apart | Haley's Comet | condense | an amorphous solid | An amorphous solid is a solid that lacks an ordered internal structure. | physics | 1 |
What is it called when you get the same result after repeating an experiment? | initiation | nucleus of atom | control | replication | Getting the same result when an experiment is repeated is called replication. If research results can be replicated, it means they are more likely to be correct. | physics | 2 |
What is the largest human organ? | heat up | chiropractor chiropractors | all day | skin | human body system that includes the skin, nails, and hair. | biology | 2 |
In the chest, the trachea divides as it enters the lungs to form the right and left what? | atrium | persistent cell division | blood pellets | bronchi | In the chest, the trachea divides as it enters the lungs to form the right and left bronchi . The bronchi contain cartilage, which prevents them from collapsing. Mucus in the bronchi traps any remaining particles in air. Tiny, hair-like structures called cilia line the bronchi and sweep the particles and mucus toward the throat so they can be expelled from the body. | biology | 3 |
Many objects have color because they contain what? | many observations | hum | seawater strength | pigments | Many objects have color because they contain pigments. A pigment is a substance that colors materials by reflecting light of certain wavelengths and absorbing light of other wavelengths. A very common pigment is the dark green pigment called chlorophyll, which is found in plants. Chlorophyll absorbs all but green wavelengths of visible light. Pigments are also found in many manufactured products. They are used to color paints, inks, and dyes. Just three pigments, called primary pigments, can be combined to produce all other colors. The primary colors of pigments are the same as the secondary colors of light: cyan, magenta, and yellow. | physics | 0 |
What is the process of action potentials in myelinated axons jumping between the nodes of ranvier called? | pinworm conduction | roots and decay | postphase | saltatory conduction | biology | 3 |
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What do craters and rifts become when the fill with water? | centricles | Shield | minor and explosive | lakes | Craters and rifts become lakes when they fill with water. Where does the water come from?. | geography | 0 |
What kind of power does not produce any pollutants, but produces waste that can be difficult to dispose of? | cool | Gliding | biofuel | nuclear | Nuclear power is a controversial subject in California and most other places. Nuclear power has no pollutants including no carbon emissions. However, power plants are not always safe. The long-term disposal of wastes is a problem that has not yet been solved. The future of nuclear power is murky. Find out more at: http://science. kqed. org/quest/audio/new-nuclear/. | physics | 3 |
What is the long, narrow tube that carries food from the pharynx to the stomach by the mechanism of peristalsis? | spinal cord | gallbladder | liver | esophagus | The esophagus is a long, narrow tube that carries food from the pharynx to the stomach. It has no other purpose. Food moves through the esophagus because of peristalsis. At the lower end of the esophagus, a circular muscle, called a sphincter, controls the opening to the stomach. The sphincter relaxes to let food pass into the stomach. Then the sphincter contracts to prevent food from passing back into the esophagus. | biology | 3 |
What is the temperature at which condensation of water vapor occurs called? | space shuttles | the tipping point | amphiarthroses | the dew point | The temperature at which condensation of water vapor occurs is called the dew point. The dew point varies depending on air temperature and moisture content. | physics | 2 |
Alkenes have double bonds while alkynes have what? | chlorine ions | copper alloy | equal bonds | triple bonds | Alkenes have double bonds; alkynes have triple bonds. Both undergo addition reactions. | chemistry | 2 |
What is our main source of aluminum ore? | tin | electrolysis | cobalt | bauxite | Weathering may concentrate some resources. In tropical climates, chemical weathering can be intense. Some minerals dissolve and water carries them away. This leaves behind the materials that are not soluble. Bauxite is aluminum oxide that collects this way. Bauxite is our main source of aluminum ore. | chemistry | 2 |
Rapidly produced genetic vairants are found in organisms with what type of generation time? | oscillating | long | repeating | short | biology | 3 |
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What are the 2 primary hosts of ebola in central africa? | rest | saline intolerant | a gonad | apes and bats | Several lethal viruses that cause viral hemorrhagic fever have been discovered, two of which are shown in the Figure below . Ebola outbreaks have been limited mainly to remote areas of the world. However, they have gained extensive media attention because of the high mortality rate—23 percent to 90 percent—depending on the strain. The primary hosts of the viruses are thought to be apes in west central Africa, but the virus has also been isolated from bats in the same region. | biology | 0 |
Unlike prokaryotic cells, dna and rna synthesis in eukaryotic cells occurs in a separate compartment from synthesis of what? | ten | brickle | hull | protein | In eukaryotic cells, DNA and RNA synthesis occur in a separate compartment from protein synthesis. In prokaryotic cells, both processes occur together. What advantages might there be to separating the processes? What advantages might there be to having them occur together? The size of the genome in one of the most well-studied prokaryotes, E. coli, is 4.6 million base pairs (approximately 1.1 mm, if cut and stretched out). So how does this fit inside a small bacterial cell? The DNA is twisted by what is known as supercoiling. Supercoiling means that DNA is either under-wound (less than one turn of the helix per 10 base pairs) or over-wound (more than 1 turn per 10 base pairs) from its normal relaxed state. Some proteins are known to be involved in the supercoiling; other proteins and enzymes such as DNA gyrase help in maintaining the supercoiled structure. Eukaryotes, whose chromosomes each consist of a linear DNA molecule, employ a different type of packing strategy to fit their DNA inside the nucleus (Figure 14.11). At the most basic level, DNA is wrapped around proteins known as histones to form structures called nucleosomes. The histones are evolutionarily conserved proteins that are rich in basic amino acids and form an octamer. The DNA (which is negatively charged because of the phosphate groups) is wrapped tightly around the histone core. This nucleosome is linked to the next one with the help of a linker DNA. This is also known as the “beads on a string” structure. This is further compacted into a 30 nm fiber, which is the diameter of the structure. At the metaphase stage, the chromosomes are at their most compact, are approximately 700 nm in width, and are found in association with scaffold proteins. In interphase, eukaryotic chromosomes have two distinct regions that can be distinguished by staining. The tightly packaged region is known as heterochromatin, and the less dense region is known as euchromatin. Heterochromatin usually contains genes that are not expressed, and is found in the regions of the centromere and telomeres. The euchromatin usually contains genes that are transcribed, with DNA packaged around nucleosomes but not further compacted. | biology | 0 |
What important organelle (that would otherwise be centrally located and crucial to the cell's survival) do prokaryotic cells lack? | trend infections | electrons | intestine | nucleus | Cell division is simpler in prokaryotes than eukaryotes because prokaryotic cells themselves are simpler. Prokaryotic cells have a single circular chromosome, no nucleus, and few other organelles. Eukaryotic cells, in contrast, have multiple chromosomes contained within a nucleus, and many other organelles. All of these cell parts must be duplicated and then separated when the cell divides. A chromosome is a molecule of DNA, and will be the focus of a subsequent concept. | biology | 1 |
What is the outer layer of an axon that acts like a layer of insulation, similar to the plastic that encases an electrical cord? | marrow gland | lipids sheath | elastases | myelin sheath | The axon of many neurons has an outer layer called a myelin sheath (see Figure above ). Myelin is a lipid produced by a type of a glial cell known as a Schwann cell. The myelin sheath acts like a layer of insulation, similar to the plastic that encases an electrical cord. Regularly spaced nodes, or gaps, in the myelin sheath allow nerve impulses to skip along the axon very rapidly. | biology | 1 |
What occurs when some members of a species become geographically separated? | clouds level | mangrove | Mountains and Creeks | allopatric speciation | New species arise in the process of speciation. Allopatric speciation occurs when some members of a species become geographically separated. They then evolve genetic differences. If the differences prevent them from interbreeding with the original species, a new species has evolved. Sympatric speciation occurs without geographic separation. | geography | 2 |
What creatures evolved from a lobe-finned lungfish ancestor? | krebs cycle | sleep-wake cycle | shallow - posterior axis | amphibians | Fossil evidence shows that amphibians evolved about 365 million years ago from a lobe-finned lungfish ancestor. As the earliest land vertebrates, they were highly successful. Some of them were much larger than today’s amphibians. For more than 100 million years, amphibians remained the dominant land vertebrates. Then some of them evolved into reptiles. Once reptiles appeared, with their amniotic eggs, they replaced amphibians as the dominant land vertebrates. | biology | 1 |
What is the term for a mixture of two or more substances that has the same composition throughout? | structure | fluid | yellow solid precipitate | solution | Water is the main ingredient of many solutions. A solution is a mixture of two or more substances that has the same composition throughout. Some solutions are acids and some are bases. To understand acids and bases, you need to know more about pure water. In pure water (such as distilled water), a tiny fraction of water molecules naturally breaks down to form ions. An ion is an electrically charged atom or molecule. The breakdown of water is represented by the chemical equation. | chemistry | 3 |
What are flagellate protozoa that cause giardiasis? | sheath leaves | potassium-rich | x and y | giardia | Giardia are flagellate protozoa that cause giardiasis . The parasites enter the body through food or water that has been contaminated by feces of infected people or animals. The protozoa attach to the lining of the host’s small intestine, where they prevent the host from fully absorbing nutrients. They may also cause diarrhea, abdominal pain, and fever. A picture of a Giardia protozoan opens this concept. | biology | 1 |
Rna and dna are types of what biochemical compounds containing the elements carbon, hydrogen, oxygen, nitrogen, and phosphorus? | dramatic contact | invasive speciation | migraine | nucleic acids | Nucleic acids are one of four classes of biochemical compounds. (The other three classes are carbohydrates, proteins, and lipids. ) Nucleic acids include RNA (ribonucleic acid) as well as DNA (deoxyribonucleic acid). Both types of nucleic acids contain the elements carbon, hydrogen, oxygen, nitrogen, and phosphorus. | biology | 0 |
What are the contacts between neurons called? | electrodes | pore | impulses | synapses | 12.5 Communication Between Neurons The basis of the electrical signal within a neuron is the action potential that propagates down the axon. For a neuron to generate an action potential, it needs to receive input from another source, either another neuron or a sensory stimulus. That input will result in opening ion channels in the neuron, resulting in a graded potential based on the strength of the stimulus. Graded potentials can be depolarizing or hyperpolarizing and can summate to affect the probability of the neuron reaching threshold. Graded potentials can be the result of sensory stimuli. If the sensory stimulus is received by the dendrites of a unipolar sensory neuron, such as the sensory neuron ending in the skin, the graded potential is called a generator potential because it can directly generate the action potential in the initial segment of the axon. If the sensory stimulus is received by a specialized sensory receptor cell, the graded potential is called a receptor potential. Graded potentials produced by interactions between neurons at synapses are called postsynaptic potentials (PSPs). A depolarizing graded potential at a synapse is called an excitatory PSP, and a hyperpolarizing graded potential at a synapse is called an inhibitory PSP. Synapses are the contacts between neurons, which can either be chemical or electrical in nature. Chemical synapses are far more common. At a chemical synapse, neurotransmitter is released from the presynaptic element and diffuses across the synaptic cleft. The neurotransmitter binds to a receptor protein and causes a change in the postsynaptic membrane (the PSP). The neurotransmitter must be inactivated or removed from the synaptic cleft so that the stimulus is limited in time. The particular characteristics of a synapse vary based on the neurotransmitter system produced by that neuron. The cholinergic system is found at the neuromuscular junction and in certain places within the nervous system. Amino acids, such as glutamate, glycine, and gamma-aminobutyric acid (GABA) are used as neurotransmitters. Other neurotransmitters are the result of amino acids being enzymatically changed, as in the biogenic amines, or being covalently bonded together, as in the neuropeptides. | biology | 3 |
What is the color of the powder of a mineral? | blue | the endodermis | organic | streak | Streak is the color of the powder of a mineral. To do a streak test, you scrape the mineral across an unglazed porcelain plate. The plate is harder than many minerals, causing the minerals to leave a streak of powder on the plate. The color of the streak often differs from the color of the larger mineral sample, as Figure below shows. | chemistry | 2 |
What basic plant structure facilitates dispersal of pollen and fruit by raising reproductive structures? | gap genes | Width | ejected quills | stem | biology | 0 |
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What type of compound is essential to life? | sublimation | methyl | double-replacement reaction | water | Water is essential to life because chemical reactions within cells take place in water. Most people can survive only a few days without consuming water to replace their water losses. How do you lose water?. | chemistry | 2 |
Which part of the ear amplifies the sound waves? | cochlea | algebra | sound kinetic theory | middle ear | The outer ear catches sound waves and funnels them to the middle ear. The middle ear amplifies the sound waves and passes them to the inner ear. The inner ear changes the sound waves to electrical signals. The signals travel to the brain, which interprets the sounds. | physics | 1 |
The shape of a virus is determined by the type and arrangement of proteins in its what? | nuclei | enamel | sperm radicle | capsid | 22.1 Introduction Viruses are the smallest biological particle (the tiniest are only 20 nm in diameter). However, they are not biological organisms so they are not classified in any kingdom of living things. They do not have any organelles and cannot respire or perform metabolic functions. Viruses are merely strands of DNA or RNA surrounded by a protective protein coat called a capsid. Viruses only come to life when they have invaded a cell. Outside of a host cell, viruses are completely inert. Since first being identified in 1935, viruses have been classified into more than 160 major groups. Viruses are classified based on their shape, replication properties, and the diseases that they cause. Furthermore, the shape of a virus is determined by the type and arrangement of proteins in its capsid. Viruses pathogenic to humans are currently classified into 21 groups. Viruses can also attack bacteria and infect bacterial cells. Such viruses are called bacteriophages. | biology | 3 |
What is the rising and sinking of warm and cooler material called? | membrane voltage | a prism | conveyance | convection | Hot lower mantle material rises upward ( Figure below ). As it rises, it cools. At the top of the mantle it moves horizontally. Over time it becomes cool and dense enough that it sinks. Back at the bottom of the mantle, it travels horizontally. Eventually the material gets to the location where warm mantle material is rising. The rising and sinking of warm and cooler material is called convection . | physics | 2 |
What is a group of connected cells that have a similar function within an organism called? | lateral line system | raise birds | impermeability | tissue | A tissue is a group of connected cells that have a similar function within an organism. More complex organisms such as jellyfish, coral, and sea anemones have a tissue level of organization. For example, jellyfish have tissues that have separate protective, digestive, and sensory functions. | biology | 1 |
The number of what subatomic particles can vary between atoms of the same element? | radioactive dating | draining universe | basic | neutrons | As stated earlier, not all atoms of a given element are identical. Specifically, the number of neutrons in the nucleus can vary for many elements. As an example, naturally occurring carbon exists in three forms, which are illustrated in Figure below . | physics | 1 |
Water is recycled constantly through which system? | effective variable | scientific experiments | low specific heat | the ecosystem | Water is recycled constantly through the ecosystem. That means any water you drank today has been around for millions of years. You could be drinking water that was once drunk by George Washington, the first humans, or even the dinosaurs. | physics | 2 |
The process in which organ systems work to maintain a stable internal environment is called what? | homeostatic regulation | upper atmosphere | knowledge | homeostasis | The process in which organ systems work to maintain a stable internal environment is called homeostasis . Keeping a stable internal environment requires constant adjustments. Here are just three of the many ways that human organ systems help the body maintain homeostasis:. | biology | 0 |
What do scientist's believe mercury's core is mostly made of? | pH scale | spontaneous rate | Tylenol | melted iron | Figure below shows a diagram of Mercury’s interior. Mercury is one of the densest planets. Scientists think that the interior contains a large core made mostly of melted iron. Mercury's core takes up about 42% of the planet's volume. Mercury's highly cratered surface is evidence that Mercury is not geologically active. | chemistry | 0 |
What material comprises the sun and other stars, as well as lightning and the northern lights? | astronomers | morphology | doors | plasma | The sun and other stars consist of plasma. Plasma is also found naturally in lightning and the northern and southern lights. Human-made plasma is found in fluorescent lights, plasma TV screens, and plasma spheres. | physics | 0 |
The function of which organ is to filter blood and form urine? | erosion | lactic acids | sweat | kidneys | biology | 2 |
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The attraction between all objects in the universe is known as ______. | diamonds | epistemology | rest zeros | gravity | All objects in the universe have an attraction to each other. This attraction is known as gravity ( Figure below ). The strength of the force of gravity depends on two things. One is the mass of the objects. The other is the distance between the objects. As an object's mass increases, the attraction increases. As the distance between the objects increases, the attraction decreases. | physics | 0 |
Friction causes the molecules on rubbing surfaces to move faster, which produces what? | normal force | parasite | electron transport | heat | You know that friction produces heat. That’s why rubbing your hands together makes them warmer. But do you know why the rubbing produces heat? Friction causes the molecules on rubbing surfaces to move faster, so they have more heat energy. Heat from friction can be useful. It not only warms your hands. It also lets you light a match (see Figure below ). On the other hand, heat from friction can be a problem inside a car engine. It can cause the car to overheat. To reduce friction, oil is added to the engine. Oil coats the surfaces of moving parts and makes them slippery so there is less friction. | physics | 0 |
The cell wall acts as an extra layer of protection, helps the cell maintain its shape, and prevents what? | their mouth | reserves | femur | dehydration | Most prokaryotes have a peptidoglycan cell wall and many have a polysaccharide capsule (Figure 4.5). The cell wall acts as an extra layer of protection, helps the cell maintain its shape, and prevents dehydration. The capsule enables the cell to attach to surfaces in its environment. Some prokaryotes have flagella, pili, or fimbriae. Flagella are used for locomotion. Pili are used to exchange genetic material during a type of reproduction called conjugation. Fimbriae are used by bacteria to attach to a host cell. | biology | 1 |
What's another term for egg-laying mammals? | simple inorganic molecules | salty water | invasive exotic plants | monotremes | There are very few living species of monotremes, or egg-laying mammals. They include the echidna and platypus, both pictured in Figure below . Monotremes are found only in Australia and the nearby island of New Guinea. | biology | 2 |
What code is the same in all living things and shows that all organisms are related by descent from a common ancestor? | time spent | .250 million | stars | genetic | The genetic code is the same in all living things. This shows that all organisms are related by descent from a common ancestor. | biology | 3 |
All animals that derive energy from food are classified as what? | life cycles | lifeforms | white blood cell | heterotrophs | Figure 15.2 All animals that derive energy from food are heterotrophs. The (a) black bear is an omnivore, eating both plants and animals. The (b) heartworm Dirofilaria immitis is a parasite that derives energy from its hosts. It spends its larval stage in mosquitos and its adult stage infesting the hearts of dogs and other mammals, as shown here. (credit a: modification of work by USDA Forest Service; credit b: modification of work by Clyde Robinson). | biology | 3 |
Through which process is the human gene for insulin placed into bacteria? | absorption | migration | mutation | transformation | Through the process of transformation, the human gene for insulin is placed into bacteria. The bacteria then use that gene to make a protein. The protein can be separated from the bacteria and then used to treat patients. The mass production of insulin by bacteria made this medicine much more affordable. | biology | 3 |
What is a symbiotic relationship in which both species benefit? | small size | nodes | parasitism | mutualism | Mutualism is a symbiotic relationship in which both species benefit. An example of mutualism involves goby fish and shrimp (see Figure below ). The nearly blind shrimp and the fish spend most of their time together. The shrimp maintains a burrow in the sand in which both the fish and shrimp live. When a predator comes near, the fish touches the shrimp with its tail as a warning. Then, both fish and shrimp retreat to the burrow until the predator is gone. From their relationship, the shrimp gets a warning of approaching danger. The fish gets a safe retreat and a place to lay its eggs. | biology | 3 |
What is the term for longer chains of monosaccharides ? | oligosaccharides | their colors | blood pellets | polysaccharides | Longer chains of monosaccharides are referred to as polysaccharides . Starch, glycogen, and cellulose are three extremely common polysaccharides made entirely out of glucose molecules. The differences lie in the types of bonds between the glucose units and the extent of branching in the carbohydrate chain. Starch is found in plants and is consumed as part of our diet. Glycogen is made by the body and is a storage form of glucose for when the cells need extra energy. Cellulose is another long-chain polysaccharide found in plants. Unlike starch and glycogen, the human body cannot break cellulose down into molecules of glucose. Although cellulose does not have any nutritional value in terms of calories, it is a major component of dietary fiber, which has other digestive benefits. | biology | 1 |
Electrical potential energy can be described by the equation pe = qv, where q is the electric charge and v is what? | frequency | permanent magnet | wavelength density | voltage | This equation is based on the conservation of energy and conservation of charge. Electrical potential energy can be described by the equation PE = qV , where q is the electric charge and V is the voltage. Thus the energy supplied by the source is qV , while that dissipated by the resistors is. | physics | 3 |
What are broad explanations that are widely accepted as true? | scientific hypotheses | scientific experiments | magnemite | scientific theories | Scientific theories are broad explanations that are widely accepted as true. This is because they are supported by a great deal of evidence. | physics | 3 |
What process is at work when warm air or water rises, and cool air or water sinks? | salts | evaporation | stellar explosions | convection | Warmer, lighter air is more buoyant than the cooler air above it. So the warm air rises. The cooler air is denser than the air beneath it. So it sinks down. This is convection: warm air rises, and cool air sinks. Warm fluids can undergo convection as well. This is described in the chapter Plate Tectonics . | physics | 2 |
If force is applied further away from a pivot point, than what kind of acceleration will be greater? | solar energy | though the nucleus | string theory | angular | 10.3 Dynamics of Rotational Motion: Rotational Inertia If you have ever spun a bike wheel or pushed a merry-go-round, you know that force is needed to change angular velocity as seen in Figure 10.10. In fact, your intuition is reliable in predicting many of the factors that are involved. For example, we know that a door opens slowly if we push too close to its hinges. Furthermore, we know that the more massive the door, the more slowly it opens. The first example implies that the farther the force is applied from the pivot, the greater the angular acceleration; another implication is that angular acceleration is inversely proportional to mass. These relationships should seem very similar to the familiar relationships among force, mass, and acceleration embodied in Newton’s second law of motion. There are, in fact, precise rotational analogs to both force and mass. | physics | 1 |
The kinetic-molecular theory as it applies to gases has how many basic assumptions? | through intercellular clefts | stibium | psilopsybin | five | The kinetic-molecular theory as it applies to gases has five basic assumptions. | chemistry | 0 |
During photosynthesis, what is energy from the sun converted to after entering a plant? | bile and lymph | calculators | convulsive | glucose | Cellular respiration and photosynthesis are direct opposite reactions. Energy from the sun enters a plant and is converted into glucose during photosynthesis. Some of the energy is used to make ATP in the mitochondria during cellular respiration, and some is lost to the environment as heat. | biology | 0 |
Formic acid is found in the secretions of? | byproduct energy | Two ions need to be the same size | acid rain | stinging ants | where R can be an alkyl group, an aryl group, or a hydrogen atom. The simplest example, HCO2H, is formic acid, so called because it is found in the secretions of stinging ants (from the Latin formica, meaning “ant”). Another example is acetic acid(CH3CO2H), which is found in vinegar. Like many acids, carboxylic acids tend to have sharp odors. For example, butyric acid (CH3CH2CH2CO2H), is responsible for the smell of rancid butter, and the characteristic odor of sour milk and vomit is due to lactic acid [CH3CH(OH)CO2H]. Some common carboxylic acids are shown in Figure 2.21 "Some Common Carboxylic Acids". where R can be an alkyl group, an aryl group, or a hydrogen atom. The simplest example, HCO2H, is formic acid, so called because it is found in the secretions of stinging ants (from the Latin formica, meaning “ant”). Another example is acetic acid(CH3CO2H), which is found in vinegar. Like many acids, carboxylic acids tend to have sharp odors. For example, butyric acid (CH3CH2CH2CO2H), is responsible for the smell of rancid butter, and the characteristic odor of sour milk and vomit is due to lactic acid [CH3CH(OH)CO2H]. Some common carboxylic acids are shown in Figure 2.21 "Some Common Carboxylic Acids". | chemistry | 2 |
What do hydrophilic substances have an affinity for? | heat | air | essential dioxide | water | chemistry | 2 |
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What is a structure that consists of two or more types of tissues that work together to do the same job? | permeation | the colon | strengthen it | organ | After tissues, organs are the next level of organization of the human body. An organ is a structure that consists of two or more types of tissues that work together to do the same job. Examples of human organs include the brain, heart, lungs, skin, and kidneys. Human organs are organized into organ systems, many of which are shown in Figure below . An organ system is a group of organs that work together to carry out a complex overall function. Each organ of the system does part of the larger job. | biology | 0 |
What is formed when amino acids are linked together in a long chain? | water molecule | accretion bond | molecular sequence | protein | Many amino acids can be linked together to form a long chain known as a protein . These linkages are formed when the carboxylic acid of one amino acid reacts with the amine of another to produce an amide (see Figure below ). | chemistry | 1 |
Both diffusion and effusion are related to the speed at which what objects move? | humidity and pressure | amorphous | copper molecules | gas molecules | A related process to diffusion is the effusion. Effusion is the process of a confined gas escaping through a tiny hole in its container. Effusion can be observed by the fact that a helium-filled balloon will stop floating and sink to the floor after a day or so. This is because the helium gas effuses through tiny pores in the balloon. Both diffusion and effusion are related to the speed at which various gas molecules move. Gases that have a lower molar mass effuse and diffuse at a faster rate than gases that have a higher molar mass. | physics | 1 |
Baroreceptors in the aortic arch and carotid sinuses monitor what level in the body? | temperature | two halves | vaporization | blood pressure | 25.9 Regulation of Fluid Volume and Composition The major hormones regulating body fluids are ADH, aldosterone and ANH. Progesterone is similar in structure to aldosterone and can bind to and weakly stimulate aldosterone receptors, providing a similar but diminished response. Blood pressure is a reflection of blood volume and is monitored by baroreceptors in the aortic arch and carotid sinuses. When blood pressure increases, more action potentials are sent to the central nervous system, resulting in greater vasodilation, greater GFR, and more water lost in the urine. ANH is released by the cardiomyocytes when blood pressure increases, causing Na+ and water loss. ADH at high levels causes vasoconstriction in addition to its action on the collecting ducts to recover more water. Diuretics increase urine volume. Mechanisms for controlling Na+ concentration in the blood include the renin–angiotensin–aldosterone system and ADH. When Na+ is retained, K+ is excreted; when Na+ is lost, K+ is retained. When circulating Ca++ decreases, PTH stimulates the reabsorption of Ca++ and inhibits reabsorption of HPO 24 − . pH is regulated through buffers, expiration of CO2, and excretion of acid or base by the kidneys. The breakdown of amino acids produces ammonia. Most ammonia is converted into less-toxic urea in the liver and excreted in the urine. Regulation of drugs is by glomerular filtration, tubular secretion, and tubular reabsorption. | biology | 2 |
The electronegativity of an element increases with increasing of what state? | bacterial transport | contraceptive use | balance | oxidation | Oxides As with the halides, the nature of bonding in oxides of the transition elements is determined by the oxidation state of the metal. Oxides with low oxidation states tend to be more ionic, whereas those with higher oxidation states are more covalent. These variations in bonding are because the electronegativities of the elements are not fixed values. The electronegativity of an element increases with increasing oxidation state. Transition metals in low oxidation states have lower electronegativity values than oxygen; therefore, these metal oxides are ionic. Transition metals in very high oxidation states have electronegativity values close to that of oxygen, which leads to these oxides being covalent. The oxides of the first transition series can be prepared by heating the metals in air. These oxides are Sc2O3, TiO2, V2O5, Cr2O3, Mn3O4, Fe3O4, Co3O4, NiO, and CuO. Alternatively, these oxides and other oxides (with the metals in different oxidation states) can be produced by heating the corresponding hydroxides, carbonates, or oxalates in an inert atmosphere. Iron(II) oxide can be prepared by heating iron(II) oxalate, and cobalt(II) oxide is produced by heating cobalt(II) hydroxide:. | physics | 1 |
Animals require air, water, and what in order to live and survive? | shade | survival dormancy | measurements | food? | biology | 3 |
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How many types of bosons are there? | a cation | minute | torr | four | There are four known types of bosons, which are force-carrying particles. Each of these bosons carries a different fundamental force between interacting particles. In addition, there is a particle which may exist, called the "Higgs Boson", which gives objects the masses they have. Some types of bosons have mass; others are massless. Bosons have an electric charge of +1, -1, or 0. | physics | 1 |
What astronomical phenomenon, formed of split asteroids or planetary rocks, provides clues about our solar system? | stars | refraction | induced permeation | meteorites | Meteorites provide clues about our solar system. Many were formed in the early solar system ( Figure below ). Some are from asteroids that have split apart. A few are rocks from nearby bodies like Mars. For this to happen, an asteroid smashed into Mars and sent up debris. A bit of the debris entered Earth’s atmosphere as a meteor. | physics | 1 |
An electron possesses both particle and these? | they are equal | existence and deduction | synchrony | wave properties | An electron possesses both particle and wave properties. CONCEPTUAL PROBLEMS 1. | physics | 0 |
What are mutant versions of normal genes called? | myelin impulses | schwann stem cell | calcareous | proto-oncogenes | biology | 1 |
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The heart and a network of blood vessels that run throughout the body make up what organ system? | immune system | lymphatic system | respiratory system | cardiovascular system | The organs that make up the cardiovascular system are the heart and a network of blood vessels that run throughout the body. The blood in the cardiovascular system is a liquid connective tissue. Figure below shows the heart and major vessels through which blood flows in the system. The heart is basically a pump that keeps blood moving through the blood vessels. | biology | 3 |
When a predator kills and eats its prey, what sort of predation is this referred to as? | Common Cells | carbon fixation | digestive flora | true | True predation is when a predator kills and eats its prey. Some predators of this type, such as jaguars, kill large prey. They tear it apart and chew it before eating it. Others, like bottlenose dolphins or snakes, may eat their prey whole. In some cases, the prey dies in the mouth or the digestive system of the predator. Baleen whales, for example, eat millions of plankton at once. The prey is digested afterward. True predators may hunt actively for prey, or they may sit and wait for prey to get within striking distance. Certain traits enable organisms to be effective hunters. These include camouflage, speed, and heightened senses. These traits also enable certain prey to avoid predators. | biology | 0 |
Pressure, volume, and temperature are related by which law? | laplacian | atomic | the Krebs cycle | gas law | Pressure, volume, and temperature are related by the combined gas law. | physics | 1 |
Different forms, or allotropes, of carbon are diamond, graphite, and what? | oxygen bonding | spicule | phylum | fullerenes | Different forms, or allotropes, of carbon are diamond, graphite, and fullerenes. | physics | 0 |
What is the process in which organisms reproduce sexually by joining gametes called? | 20 % | gigantism | they could bear fruit | fertilization | Organisms that reproduce sexually by joining gametes , a process known as fertilization , must have a mechanism to produce haploid gametes. This mechanism is meiosis , a type of cell division that halves the number of chromosomes. Meiosis occurs only in gamete producing cells within the gonads. During meiosis the pairs of chromosomes separate and segregate randomly to produce gametes with one chromosome from each pair. Meiosis involves two nuclear and cell divisions without an interphase in between, starting with one diploid cell and generating four haploid cells ( Figure below ). Each division, named meiosis I and meiosis II, has four stages: prophase, metaphase, anaphase, and telophase. These stages are similar to those of mitosis, but there are distinct and important differences. | biology | 2 |
What is the force of attraction between things that have mass | momentum | friction | motion | gravity | Gravity has traditionally been defined as a force of attraction between things that have mass. The strength of gravity between two objects depends on their mass and their distance apart. | physics | 3 |
Mitosis and meiosis are two types of what process, with dramatically different products? | exothermic | air sac | 4 billion years | cell division | Mitosis and meiosis are two types of cell division, with dramatically different products. Mitosis begins with a diploid somatic cell and ends with two genetically identical diploid cells. Meiosis begins with a diploid cell and produces four haploid genetically unique cells that form gametes. | biology | 2 |
Zinc reacting with hydrochloric acid produces bubbles of which gas? | mustard | carbon | helium | hydrogen | Zinc reacting with hydrochloric acid produces bubbles of hydrogen gas. | chemistry | 3 |
Water gains and loses what more slowly than does land, affecting seasonal conditions inland and on the coast? | minerals | the epicenter | salt and water | heat | Temperature falls from the equator to the poles. Therefore, major temperature zones are based on latitude. They include tropical, temperate, and arctic zones (see Figure below ). However, other factors besides latitude may also influence temperature. For example, land near the ocean may have cooler summers and warmer winters than land farther inland. This is because water gains and loses heat more slowly than does land, and the water temperature influences the temperature on the coast. Temperature also falls from lower to higher altitudes. That’s why tropical zone mountain tops may be capped with snow. | geography | 2 |
Covalent solutes separate into what when dissolved? | surfactants atom | second molecules | new molecules | individual molecules | Ionic solutes separate into individual ions when they dissolve. Covalent solutes separate into individual molecules. | chemistry | 3 |
What term indicates moles per liter, whereas molality is moles per kilogram of solvent? | kilocalorie | mitosis | interchangeable machines | molarity | A N SW E R S 1. Molarity is moles per liter, whereas molality is moles per kilogram of solvent. | chemistry | 1 |
Many of the hormones are secreted in response to what signals of the body? | slimy smear | nose system signals | archaeplastida | nervous system signals | may be located in organs or tissues that have functions in addition to hormone production. Hormones circulate throughout the body and stimulate a response in cells that have receptors able to bind with them. The changes brought about in the receiving cells affect the functioning of the organ system to which they belong. Many of the hormones are secreted in response to signals from the nervous system, thus the two systems act in concert to effect changes in the body. | biology | 1 |
What are two of the most common vision problems? | cross-eye and blindness | blindness and astigmatism | myopia and nearsightedness | nearsightedness and farsightedness | Many people have vision problems. Often, the problem is due to the shape of the eyes and how they focus light. Two of the most common vision problems are nearsightedness and farsightedness. | physics | 3 |
Hydrochloric acid is formed when hcl is dissolved into what? | cycloalkyne | blood | evaporation solution | water | When HCl is dissolved into water, it is called hydrochloric acid. Ionic compounds and some polar compounds are completely broken apart into ions and thus conduct a current very well. A strong electrolyte is a solution in which a large fraction of the dissolved solute exists as ions. | chemistry | 2 |
Atoms of the same element that have different masses are called what? | collision theory | distances | zinc | isotopes | Isotopes are atoms of the same element that have different masses. | physics | 3 |
What term is used to describe potential energy due to an object’s shape? | gas giant | stimulated potential energy | articulation | elastic potential energy | Irrigation is the single biggest use of water. Overhead irrigation wastes a lot of water. Drip irrigation ( Figure below ) wastes a lot less. Water pipes run over the surface of the ground. Tiny holes in the pipes are placed close to each plant. Water slowly drips out of the holes and soaks into the soil around the plants. Very little of the water evaporates or runs off the ground. | physics | 3 |
What property is characterized by eddies and swirls that mix layers of fluid together, unlike laminar flow? | evaporation | distant waves | compression | turbulence | 12.4 Viscosity and Laminar Flow; Poiseuille’s Law • Laminar flow is characterized by smooth flow of the fluid in layers that do not mix. • Turbulence is characterized by eddies and swirls that mix layers of fluid together. • Fluid viscosity η is due to friction within a fluid. Representative values are given in Table 12.1. Viscosity has units of. | physics | 2 |
What process refers to a separation of charge within an atom or molecule? | depth and density | elliptical | changing system | polarization | material, and is intimately related to the polarizability of the material. Things Great and Small The Submicroscopic Origin of Polarization Polarization is a separation of charge within an atom or molecule. As has been noted, the planetary model of the atom pictures it as having a positive nucleus orbited by negative electrons, analogous to the planets orbiting the Sun. Although this model is not completely accurate, it is very helpful in explaining a vast range of phenomena and will be refined elsewhere, such as in Atomic Physics. The submicroscopic origin of polarization can be modeled as shown in Figure 19.18. | physics | 1 |
What is the largest cartilaginous fish? | recovery | dermis | beneficial | whale shark | Mike Johnston. Whale sharks are the largest cartilaginous fish . CC BY 2.0. | biology | 0 |
Capillaries in the chorionic villi filter fetal wastes out of the blood and return clean, oxygenated blood to the fetus through what? | a cell | metabolic response | microevolutions | umbilical vein | The placenta develops throughout the embryonic period and during the first several weeks of the fetal period; placentation is complete by weeks 14–16. As a fully developed organ, the placenta provides nutrition and excretion, respiration, and endocrine function (Table 28.1 and Figure 28.12). It receives blood from the fetus through the umbilical arteries. Capillaries in the chorionic villi filter fetal wastes out of the blood and return clean, oxygenated blood to the fetus through the umbilical vein. Nutrients and oxygen are transferred from maternal blood surrounding the villi through the capillaries and into the fetal bloodstream. Some substances move across the placenta by simple diffusion. Oxygen, carbon dioxide, and any other lipid-soluble substances take this route. Other substances move across by facilitated diffusion. This includes water-soluble glucose. The fetus has a high demand for amino acids and iron, and those substances are moved across the placenta by active transport. Maternal and fetal blood does not commingle because blood cells cannot move across the placenta. This separation prevents the mother’s cytotoxic T cells from reaching and subsequently destroying the fetus, which bears “non-self” antigens. Further, it ensures the fetal red blood cells do not enter the mother’s circulation and trigger antibody development (if they carry “non-self” antigens)—at least until the final stages of pregnancy or birth. This is the reason that, even in the absence of preventive treatment, an Rh− mother doesn’t develop antibodies that could cause hemolytic disease in her first Rh+ fetus. Although blood cells are not exchanged, the chorionic villi provide ample surface area for the two-way exchange of substances between maternal and fetal blood. The rate of exchange increases throughout gestation as the villi become thinner and increasingly branched. The placenta is permeable to lipid-soluble fetotoxic substances: alcohol, nicotine, barbiturates, antibiotics, certain pathogens, and many other substances that can be dangerous or fatal to the developing embryo or fetus. For these reasons, pregnant women should avoid fetotoxic substances. Alcohol consumption by pregnant women, for example, can result in a range of abnormalities referred to as fetal alcohol spectrum disorders (FASD). These include organ and facial malformations, as well as cognitive and behavioral disorders. | biology | 0 |