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What substances, which are distinct from acids and bases, form when ions form ionic bonds? | water molecules | potassium bonds | saltwater | salts | Salts Recall that salts are formed when ions form ionic bonds. In these reactions, one atom gives up one or more electrons, and thus becomes positively charged, whereas the other accepts one or more electrons and becomes negatively charged. You can now define a salt as a substance that, when dissolved in water, dissociates into ions other than H+ or OH–. This fact is important in distinguishing salts from acids and bases, discussed next. A typical salt, NaCl, dissociates completely in water (Figure 2.15). The positive and negative regions on the water molecule (the hydrogen and oxygen ends respectively) attract the negative chloride and positive sodium ions, pulling them away from each other. Again, whereas nonpolar and polar covalently bonded compounds break apart into molecules in solution, salts dissociate into ions. These ions are electrolytes; they are capable of conducting an electrical current in solution. This property is critical to the function of ions in transmitting nerve impulses and prompting muscle contraction. | chemistry | 3 |
What is the name for biochemical compounds that consist of one or more chains of small molecules called amino acids? | hinge | nose system signals | niya soils | proteins | Proteins are biochemical compounds that consist of one or more chains of small molecules called amino acids. Amino acids are the monomers of proteins. There are only about 20 different amino acids. The sequence of amino acids in chains and the number of chains in a protein determine the protein’s shape. Shapes may be very complex. You can learn more about the shapes of proteins at this link:. | biology | 0 |
What are the ionic compounds that produce negative hydroxide ions when dissolved in water? | enzymes | isotopes | acids | bases | Bases are ionic compounds that produce negative hydroxide ions (OH - ) when dissolved in water. An ionic compound contains positive metal ions and negative nonmetal ions held together by ionic bonds. (Ions are atoms that have become charged particles because they have either lost or gained electrons. ) An example of a base is sodium hydroxide (NaOH). When it dissolves in water, it produces negative hydroxide ions and positive sodium ions (Na + ). This can be represented by the equation:. | chemistry | 3 |
The atomic number of tungsten is 74. therefore, in a neutral atom of tungsten, there are 74 electrons. the atomic number of argon is 18. therefore, in a neutral atom of argon, there are how many electrons? | a flammable gas | lead | zinc | 18 | The atomic number of tungsten is 74. Therefore, in a neutral atom of tungsten, there are 74 electrons. The atomic number of argon is 18. Therefore, in a neutral atom of argon, there are 18 electrons. | physics | 0 |
What is the apparatus used for carrying out an electrolysis reaction? | heterogeneous | substrates | water cleaning | an electrolytic cell | An electrolytic cell is the apparatus used for carrying out an electrolysis reaction. In an electrolytic cell, electric current is applied to provide a source of electrons for driving the reaction in a nonspontaneous direction. In a voltaic cell, the reaction goes in a direction that releases electrons spontaneously. In an electrolytic cell, the input of electrons from an external source forces the reaction to go in the opposite direction. | chemistry | 0 |
What two ways may light be transmitted? | absorption and refraction | expands or contracts | rovers | refracted or scattered | Transmitted light may be refracted or scattered. When does each process occur?. | physics | 1 |
Triggered by changes in the environment, migration and hibernation occur as cycles on what temporal basis? | phylum arthropod | nose | cuttings | annual | Examples of behaviors with annual cycles include migration and hibernation. Both are innate behaviors. They are triggered by changes in the environment, such as the days growing shorter in the fall. | biology | 0 |
What pair of tubes that extends toward the ovaries features a fringelike structure that sweeps eggs inside? | cortisol | Mammalia felidae | Metatheria | fallopian tubes | Extending from the upper corners of the uterus are the two fallopian tubes. Each tube reaches (but is not attached to) one of the ovaries. The ovary end of the tube has a fringelike structure that moves in waves. The motion sweeps eggs from the ovary into the tube. | biology | 0 |
In most animals, what sense is related to balance or equilibrium? | flower | Fiber | musculoskeletal system | hearing | biology | 2 |
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Terminal pods are located at the end of what? | proportional distribution | splash and deposition | coal mines | stems | Mendel investigated seven different characteristics in pea plants. In this chart, cotyledons refer to the tiny leaves inside seeds. Axial pods are located along the stems. Terminal pods are located at the ends of the stems. | geography | 1 |
What forms when the spores from two parents fuse during sexual reproduction? | Longest Point | memories | occurrences | zygospore | Sexual reproduction occurs when spores from two parents fuse and form a zygospore. | biology | 1 |
What is the name of the galaxy we live in? | area | public motor | gas fumes | milky way | Like other spiral galaxies, our galaxy has a disk, a central bulge, and spiral arms. The disk is about 100,000 light-years across and 3,000 light-years thick. Most of the Galaxy’s gas, dust, young stars, and open clusters are in the disk. | physics | 0 |
What are the most common seedless vascular plants? | amphipod | frogs | ovum | ferns | Ferns are the most common seedless vascular plants ( Figure below ). They usually have large divided leaves called fronds. In most ferns, fronds develop from a curled-up formation called a fiddlehead ( Figure below ). The fiddlehead looks like the curled decoration on the end of a stringed instrument, such as a fiddle. Leaves unroll as the fiddleheads grow and expand. Ferns grow in a variety of habitats, ranging in size from tiny aquatic species to giant tropical plants. | biology | 1 |
In a monogamous pairing, a male individual is generally paired with what other type of individual in a sexual relationship? | drone | territorial | male | female | Visit this website (http://openstaxcollege. org/l/sex_selection) for informative videos on sexual selection. In monogamous systems, one male and one female are paired for at least one breeding season. In some animals, such as the gray wolf, these associations can last much longer, even a lifetime. Several explanations have been proposed for this type of. | biology | 3 |
What is a mass spectrometer used to measure? | metallic bonds | mass of water | balanced | relative atomic masses | Although the masses of the electron, the proton, and the neutron are known to a high degree of precision (Table 1.3 "Properties of Subatomic Particles*"), the mass of any given atom is not simply the sum of the masses of its electrons, protons, and neutrons. For example, the ratio of the masses of 1H (hydrogen) and 2H (deuterium) is actually 0.500384, rather than 0.49979 as predicted from the numbers of neutrons and protons present. Although the difference in mass is small, it is extremely important because it is the source of the huge amounts of energy released in nuclear reactions (Chapter 20 "Nuclear Chemistry"). Because atoms are much too small to measure individually and do not have a charge, there is no convenient way to accurately measure absolute atomic masses. Scientists can measure relative atomic masses very accurately, however, using an instrument called a mass spectrometer. The technique is conceptually similar to the one Thomson used to determine the mass-to-charge ratio of the electron. First, electrons are removed from or added to atoms or molecules, thus producing charged particles called ions. When an electric field is applied, the ions are accelerated into a separate chamber where they are deflected from their initial trajectory by a magnetic field, like the electrons in Thomson’s experiment. The extent of the deflection depends on the mass-to-charge ratio of the ion. By measuring the relative deflection of ions that have the same charge, scientists can determine their relative masses (Figure 1.25 "Determining Relative Atomic Masses Using a Mass Spectrometer"). Thus it is not possible to calculate absolute atomic masses accurately by simply adding together the masses of the electrons, the protons, and the neutrons, and absolute atomic masses cannot be measured, but relative masses can be measured very accurately. It is actually rather common in chemistry to encounter a quantity whose magnitude can be measured only relative to some other quantity, rather than absolutely. We will encounter many other examples later in this text. In such cases,. | physics | 0 |
What combines sets of genes from two different parents leading to genetically diverse offspring? | external passageway | pinworm conduction | unary | sexual reproduction | biology | 2 |
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Global warming will raise ocean levels due to melt water from glaciers and the greater volume of what? | photon belt | greenhouse gases | rock displacement | warmer water | Range shifts are already being observed: for example, some European bird species ranges have moved 91 km northward. The same study suggested that the optimal shift based on warming trends was double that distance, suggesting that the populations are not moving quickly enough. Range shifts have also been observed in plants, butterflies, other insects, freshwater fishes, reptiles, and mammals. Climate gradients will also move up mountains, eventually crowding species higher in altitude and eliminating the habitat for those species adapted to the highest elevations. Some climates will completely disappear. The rate of warming appears to be accelerated in the arctic, which is recognized as a serious threat to polar bear populations that require sea ice to hunt seals during the winter months: seals are the only source of protein available to polar bears. A trend to decreasing sea ice coverage has occurred since observations began in the mid-twentieth century. The rate of decline observed in recent years is far greater than previously predicted by climate models. Finally, global warming will raise ocean levels due to melt water from glaciers and the greater volume of warmer water. Shorelines will be inundated, reducing island size, which will have an effect on some species, and a number of islands will disappear entirely. Additionally, the gradual melting and subsequent refreezing of the poles, glaciers, and higher elevation. | geography | 2 |
What are groups of young stars loosely held together by gravity called? | fluid temperature | microwave | an atom | open clusters | Open clusters are groups of young stars loosely held together by gravity. | physics | 0 |
What does a pollinator pick up from its body and carry directly to another plant of the same species? | linear contact | spore | variable rhythm | pollen | Wind-blown pollen might land anywhere and be wasted. Another adaptation solved this problem. Plants evolved traits that attract specific animal pollinators. Like the bee in Figure below , a pollinator picks up pollen on its body and carries it directly to another plant of the same species. This greatly increases the chance that fertilization will occur. | biology | 2 |
What is formed when an oxygen atom picks up a pair of hydrogen ions from a solution? | helium giants | uv (ultraviolet) | turpentine | water | physics | 2 |
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What does the driving of turbines by the heating of water to steam accomplish? | absorption of electricity | tail bone | diffusion of electricity | generation of electricity | Nuclear reactors heat water to steam to drive a turbine for generation of electricity. | physics | 2 |
What is a device that changes kinetic energy to electrical energy through electromagnetic induction? | a diesel engine | liquids and soilds | with random charges | an electric generator | An electric generator is a device that changes kinetic energy to electrical energy through electromagnetic induction. A simple diagram of an electric generator is shown in Figure below . In a generator, some form of energy is applied to turn a shaft. This causes a coil of wire to rotate between opposite poles of a magnet. Because the coil is rotating in a magnetic field, electric current is generated in the wire. If the diagram in Figure below looks familiar to you, that’s because a generator is an electric motor in reverse. Look back at the electric motor in Figure above . If you were to mechanically turn the shaft of the motor (instead of using electromagnetism to turn it), the motor would generate electricity just like an electric generator. You can learn how to make a very simple electric generator by watching the video at the URL below. Making your own generator will help you understand how a generator works. | physics | 1 |
How many naturally occurring elements are known on earth? | cathode rays | ignoble | diffuse energy | 90 | An element, as defined in Chapter 1 "Chemistry, Matter, and Measurement", is a substance that cannot be broken down into simpler chemical substances. There are about 90 naturally occurring elements known on Earth. Using technology, scientists have been able to create nearly 30 additional elements that do not occur in nature. Today, chemistry recognizes 118 elements—some of which were created an atom at a time. Figure 2.1 "Samples of Elements" shows some of the chemical elements. | physics | 2 |
What are the two types of vesicle transport called? | eptocytosis and exocytosis | dielectric and exocytosis | embryo | endocytosis and exocytosis | biology | 3 |
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What do you call a species that has died out in the past? | alopecia | fruits and nuts | inhabit | extinct | Life is complex, and there are millions of species alive today. Many millions more lived in the past and then went extinct. Organisms include microscopic, single-celled organisms. They also include complex, multicellular animals such as you. Clearly, life science is a huge science. That’s why a life scientist usually specializes in just one field within life science. Dr. Smith, for example, specializes in ecology. You can see the focus of ecology and several other life science fields in Table below . Click on the links provided if you want to learn about careers in these fields. | biology | 2 |
Where does the embryo develop in a plant? | lung tissue | outside the female plant after fertilization | inside the stem after fertilization | inside the female plant after fertilization | In plants, the embryo develops inside of the female plant after fertilization. Algae do not keep the embryo inside of themselves but release it into water. This was the first feature to evolve that separated plants from green algae. This is also the only adaptation shared by all plants. | biology | 2 |
What is the method of setting or correcting a measuring device by matching it to known measurement standards called? | superceding wake | difference in wind | distortion | calibration | When using measuring devices, we often use a technique called calibration to increase the accuracy of our measurements. Calibration is a method of setting or correcting a measuring device by matching it to known measurement standards. To better understand calibration, we will look at the example of calibrating a thermometer. All thermometers are slightly different in their temperature readings. One way to calibrate a thermometer is by using the freezing point and boiling point of water ( Figure below ). If we know that water freezes at 0°C and boils at 100°C, we can calibrate our thermometer by measuring the temperature of ice water and of boiling water. We place the thermometer in ice water and wait for the thermometer liquid to reach a stable height, then place a mark at this height which represents 0°C. Then we place the thermometer in boiling water, and after waiting for the thermometer liquid to reach a stable height, we place a mark at this height which represents 100°C. We can then place 100 equally spaced divisions between our 0 and 100°C marks to each represent 1°C. Our thermometer has now been calibrated using the known values for the freezing point and boiling point of water, and can be used to measure temperatures of objects between 0 and 100°C. | physics | 2 |
What property of warm air causes it to rise above cold air? | higher temperature | the leaf | greater density | lower density | The warm-air vent is placed near the floor of the room. Warm air is less dense than cold air so it rises. If the warm-air vent were placed near the ceiling instead, how would this affect the transfer of thermal energy throughout the room?. | physics | 2 |
Which branch of biology studies animal behavior? | embryology | microbiology | epidermis | ethology | The branch of biology that studies animal behavior is called ethology. Ethologists usually study how animals behave in their natural environment. They try to determine the cause of behaviors, how behaviors develop, and how and why behaviors evolve. | biology | 3 |
What unit of measure is equal to the amount of work a horse can do in 1 minute? | torque | joule | at rest | horsepower | Power may be measured in a unit called the horsepower. One horsepower is the amount of work a horse can do in 1 minute, which equals 745 watts of power. | physics | 3 |
What organism is characterized by an incomplete digestive system and a single, tentacled opening? | animals to humans | overlap | coastal swell | cnidarians | Cnidarians have an incomplete digestive system with a single opening. The opening is surrounded by tentacles, which are covered with nematocyst cells and used to capture prey. Digestion takes place in the digestive cavity. Nutrients are absorbed and gases are exchanged through the cells lining this cavity. Fluid in the cavity supports and stiffens the cnidarian body. | biology | 0 |
What term is not the same as energy, but means the energy per unit charge? | filter | frequency | branched-chain isomers | voltage | The second equation is equivalent to the first. Voltage is not the same as energy. Voltage is the energy per unit charge. Thus a motorcycle battery and a car battery can both have the same voltage (more precisely, the same potential difference between battery terminals), yet one stores much more energy than the other since ΔPE = qΔV . The car battery can move more charge than the motorcycle battery, although both are 12 V batteries. | physics | 2 |
What specific part of the african violet is used to propagate other plants? | roots | petals | bloodsucking apparatuses | leaves | biology | 3 |
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What are fibers that depend on aerobic respiration called? | fragile fibers | crust | adult stages | oxidative fibers | biology | 2 |
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Which form of electromagnetic waves have more energy: low frequency wave or high frequency waves? | stream | dwarf galaxies | phsycology | high frequency waves | The energy of electromagnetic waves depends on their frequency. Low-frequency waves have little energy and are normally harmless. High-frequency waves have a lot of energy and are potentially very harmful. | physics | 2 |
Something that has all of the characteristics of life is considered to be what? | zooflagellate stage | mimivirus | parthenogenesis | alive | There is not just one distinguishing feature that separates a living thing from a non-living thing. A cat moves but so does a car. A tree grows bigger, but so does a cloud. A cell has structure, but so does a crystal. Biologists define life by listing characteristics that living things share. Something that has all of the characteristics of life is considered to be alive. The duck decoy in Figure below may look like a duck, act like a duck in that it floats about, but it is not alive. The decoy cannot reproduce, respond to its environment, or breathe. | biology | 0 |
What do the letters in our blood types represent? | polygamy | time energy | proteins | alleles | Another exception to Mendel's laws is a phenomenon called codominance . For example, our blood type shows codominance. Do you know what your blood type is? Are you A? O? AB? Those letters actually represent alleles. Unlike other traits, your blood type has three alleles, instead of two!. | biology | 1 |
The two stages of photosynthesis are the light reactions and what? | large intense | lung | absorbent | calvin cycle | The two stages of photosynthesis are the light reactions and the Calvin cycle. Do you see how the two stages are related?. | biology | 0 |
What do living things need to survive? | arachnids vertebrates | a man | heat | nutrients | There are three main ocean zones based on distance from shore. They are the intertidal zone , neritic zone , and oceanic zone . Distance from shore influences how many nutrients are in the water. Why? Most nutrients are washed into ocean water from land. Therefore, water closer to shore tends to have more nutrients. Living things need nutrients. So distance from shore also influences how many organisms live in the water. | biology | 1 |
The denser regions of the electron cloud are called what? | evaporates | electrons to neutrons | electric combustion | orbitals | Some regions of the electron cloud are denser than others. The denser regions are areas where electrons are most likely to be. These regions are called orbitals . Each orbital has a maximum of just two electrons. Different energy levels in the cloud have different numbers of orbitals. Therefore, different energy levels have different maximum numbers of electrons. Table below lists the number of orbitals and electrons for the first four energy levels. Energy levels farther from the nucleus have more orbitals. Therefore, these levels can hold more electrons. | physics | 2 |
In studying energy, what term do scientists use to refer to the matter and its environment involved in energy transfers? | world | co2 | ecosystem | system | 6.3 The Laws of Thermodynamics In studying energy, scientists use the term “system” to refer to the matter and its environment involved in energy transfers. Everything outside of the system is called the surroundings. Single cells are biological systems. Systems can be thought of as having a certain amount of order. It takes energy to make a system more ordered. The more ordered a system is, the lower its entropy. Entropy is a measure of the disorder of a system. As a system becomes more disordered, the lower its energy and the higher its entropy become. A series of laws, called the laws of thermodynamics, describe the properties and processes of energy transfer. The first law states that the total amount of energy in the universe is constant. This means that energy can’t be created or destroyed, only transferred or transformed. The second law of thermodynamics states that every energy transfer involves some loss of energy in an unusable form, such as heat energy, resulting in a more disordered system. In other words, no energy transfer is completely efficient and tends toward disorder. | physics | 3 |
To measure what changes that occur in chemical reactions, chemists usually use a related thermodynamic quantity, calledenthalpy? | biogeochemical cycles | carbon fiber | non-harmonic bonds | energy | (a) Initially, the system (a copper penny and concentrated nitric acid) is at atmospheric pressure. (b) When the penny is added to the nitric acid, the volume of NO2 gas that is formed causes the piston to move upward to maintain the system at atmospheric pressure. In doing so, the system is performing work on its surroundings. The symbol E in represents the internal energy of a system, which is the sum of the kinetic energy and potential energy of all its components. It is the change in internal energy that produces heat plus work. To measure the energy changes that occur in chemical reactions, chemists usually use a related thermodynamic quantity calledenthalpy (H) (from the Greek enthalpein, meaning “to warm”). The enthalpy of a system is defined as the sum of its internal energy E plus the product of its pressure Pand volume V:. | chemistry | 1 |
A system in what state cannot spontaneously change, and therefore can do no work? | relative atomic masses | nebuli | wind resistance | equilibrium | physics | 0 |
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What is a species that plays an especially important role in it's community called? | Leader | Megasporangia | mitochondria molecules | keystone | Some predator species are known as keystone species. A keystone species is one that plays an especially important role in its community. Major changes in the numbers of a keystone species affect the populations of many other species in the community. For example, some sea star species are keystone species in coral reef communities. The sea stars prey on mussels and sea urchins, which have no other natural predators. If sea stars were removed from a coral reef community, mussel and sea urchin populations would have explosive growth. This, in turn, would drive out most other species. In the end, the coral reef community would be destroyed. | biology | 1 |
What term that shows how fast a population is growing includes new members added to the population over a given period, as well as old members removed from the population? | emigration | right atrium | muscle tissues | growth rate | The population growth rate is how fast a population is growing. The letter r stands for the growth rate. The growth rate equals the number of new members added to the population in a year for each 100 members already in the population. The growth rate includes new members added to the population and old members removed from the population. Births add new members to the population. Deaths remove members from the population. The formula for population growth rate is:. | biology | 2 |
The rings of what planet can be easily seen from earth? | extinction | size and direction | jupiter | saturn | All of the outer planets have numerous moons. They also have planetary rings made of dust and other small particles. Only the rings of Saturn can be easily seen from Earth. | physics | 2 |
What planet is a blue green color? | nitrogen oxides | Mars | equilibrium constants | uranus | Uranus is a lot like Jupiter and Saturn. The planet is composed mainly of hydrogen and helium. There is a thick layer of gas on the outside. Further on the inside is liquid. But Uranus has a higher percentage of icy materials than Jupiter and Saturn. These materials include water, ammonia, and methane. Uranus is also different because of its blue-green color. Clouds of methane filter out red light. This leaves a blue-green color. The atmosphere of Uranus has bands of clouds. These clouds are hard to see in normal light. The result is that the planet looks like a plain blue ball. | physics | 1 |
The simplest class of organic compounds is the what? | fungi | particles | Phenols | hydrocarbons | isolating the individual components, preservationists are better able to determine the condition of an object and those books and documents most in need of immediate protection. The simplest class of organic compounds is the hydrocarbons, which consist entirely of carbon and hydrogen. Petroleum and natural gas are complex, naturally occurring mixtures of many different hydrocarbons that furnish raw materials for the chemical industry. The four major classes of hydrocarbons are the alkanes, which contain only carbon–hydrogen and carbon–carbon single bonds; the alkenes, which contain at least one carbon–carbon double bond; the alkynes, which contain at least one carbon–carbon triple bond; and the aromatic hydrocarbons, which usually contain rings of six carbon atoms that can be drawn with alternating single and double bonds. Alkanes are also called saturated hydrocarbons, whereas hydrocarbons that contain multiple bonds (alkenes, alkynes, and aromatics) are unsaturated. | chemistry | 2 |
Some meteorites are made of iron and nickel and are thought to be very similar to what part of the earth? | ion | primary succession | eight | core | Scientists study meteorites to learn about Earth’s interior. Meteorites formed in the early solar system. These objects represent early solar system materials. Some meteorites are made of iron and nickel. They are thought to be very similar to Earth's core ( Figure below ). An iron meteorite is the closest thing to a sample of the core that scientists can hold in their hands!. | geography | 0 |
Which pathway carries somatosensory information from the face, head, mouth, and nasal cavity? | cirrhosis | hinge joint | dual pathway | trigeminal pathway | The trigeminal pathway carries somatosensory information from the face, head, mouth, and nasal cavity. As with the previously discussed nerve tracts, the sensory pathways of the trigeminal pathway each involve three successive neurons. First, axons from the trigeminal ganglion enter the brain stem at the level of the pons. These axons project to one of three locations. The spinal trigeminal nucleus of the medulla receives information similar to that carried by spinothalamic tract, such as pain and temperature sensations. Other axons go to either the chief sensory nucleus in the pons or the mesencephalic nuclei in the midbrain. These nuclei receive information like that carried by the dorsal column system, such as touch, pressure, vibration, and proprioception. Axons from the second neuron decussate and ascend to the thalamus along the trigeminothalamic tract. In the thalamus, each axon synapses with the third neuron in its respective pathway. Axons from the third neuron then project from the thalamus to the primary somatosensory cortex of the cerebrum. The sensory pathway for gustation travels along the facial and glossopharyngeal cranial nerves, which synapse with neurons of the solitary nucleus in the brain stem. Axons from the solitary nucleus then project to the ventral posterior nucleus of the thalamus. Finally, axons from the ventral posterior nucleus project to the gustatory cortex of the cerebral cortex, where taste is processed and consciously perceived. The sensory pathway for audition travels along the vestibulocochlear nerve, which synapses with neurons in the cochlear nuclei of the superior medulla. Within the brain stem, input from either ear is combined to extract location information from the auditory stimuli. Whereas the initial auditory stimuli received at the cochlea strictly represent the frequency—or pitch—of the stimuli, the locations of sounds can be determined by comparing information arriving at both ears. | biology | 3 |
The amount of kinetic energy in a moving object depends directly on its mass and what else? | climatologists | a projection | direction | velocity | The amount of kinetic energy in a moving object depends directly on its mass and velocity. An object with greater mass or greater velocity has more kinetic energy. You can calculate the kinetic energy of a moving object with this equation:. | physics | 3 |
Cycling, shoveling snow and cross-country skiing are examples of what kind of heart-strengthening activity? | exercise | metabolism | fog | aerobic | When done regularly, aerobic activities, such as cycling, make the heart stronger. Other aerobic activities include mowing lawn, shoveling snow and cross country skiing. | geography | 2 |
What take the shape of their container, and are relatively easy to compress? | corrugated | ions and electrons | area | gases | The story is quite different for gases. Gases take the shape of their container, and they are relatively easy to compress. There are fewer gas particles per unit volume than for the same substance in the liquid or solid form. In fact, the liquid form of a given material is generally several hundred times more dense than the gas form at normal pressures. Despite the large amounts of empty space, a sample of a gas contains many particles moving around, colliding and imparting force on their surroundings. For example, in a one mole sample of gas at 0°C and 1 atm of pressure, each cubic centimeter contains roughly 2.7 × 10 19 molecules. Each molecule participates in several billion collisions every second, moving only about 10-100 nanometers between collisions. Additionally, these gas particles move at very high speeds. For example, at 25°C, the average speed of hydrogen molecules in a sample of hydrogen gas is 1960 m/s. | physics | 1 |
What is moving air called? | position vector | curve dating | vapor engine | wind | Moving air, like moving water, causes erosion. Moving air is called wind. | physics | 0 |
What property makes bone marrow cells ideal for gene therapy? | devices respiration | exhibit | embryology | lifelong reproduction | biology | 0 |
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What is the name of the two metalloids in the carbon group called? | silver and gold | pancreas | silicon and gold | silicon and germanium | Group 14 is called the carbon group. This group contains two metalloids: silicon and germanium. Carbon is a nonmetal, and the remaining elements in this group are metals. | physics | 3 |
What is the name of the zone where water is deeper than 200 meters called? | eccentric zone | first position | euphotic zone | aphotic zone | The aphotic zone is water deeper than 200 meters. This is where too little sunlight penetrates for photosynthesis to occur. As a result, producers must make "food" by chemosynthesis , or the food must drift down from the water above. | geography | 2 |
Diagnosing and treating cancer is a beneficial use of what potentially dangerous energy? | dna and proteins | significant nervous system | green water | radiation | Radiation has several important uses, including diagnosing and treating cancer. | biology | 2 |
Many adults and some children suffer from a deficiency of lactase. these individuals are said to be lactose intolerant because they cannot digest the lactose found in what? | cranium | reactive product | it stays the same | milk | Many adults and some children suffer from a deficiency of lactase. These individuals are said to be lactose intolerant because they cannot digest the lactose found in milk. A more serious problem is the genetic disease galactosemia, which results from the absence of an enzyme needed to convert galactose to glucose. Certain bacteria can metabolize lactose, forming lactic acid as one of the products. This reaction is responsible for the “souring” of milk. | biology | 1 |
Three-prong plugs, circuit breakers, and gfci outlets are safety features that recognize the danger of what? | one quark | gaseous | magnetism | electricity | Because electricity can be so dangerous, safety features are built into modern electric circuits and devices. They include three-prong plugs, circuit breakers, and GFCI outlets. You can read about these three safety features in the Figure below . You can learn more about electric safety features in the home by watching the video at this URL: http://www. dailymotion. com/video/x6fg5i_basics-of-your-home-s-electrical-sy_school . | physics | 2 |
Catabolic reactions break down large organic molecules into smaller molecules, releasing the energy contained in what? | alkalinity | applied water | lattice groups | chemical bonds | Catabolic Reactions Catabolic reactions break down large organic molecules into smaller molecules, releasing the energy contained in the chemical bonds. These energy releases (conversions) are not 100 percent efficient. The amount of energy released is less than the total amount contained in the molecule. Approximately 40 percent of energy yielded from catabolic reactions is directly transferred to the high-energy molecule adenosine triphosphate (ATP). ATP, the energy currency of cells, can be used immediately to power molecular machines that support cell, tissue, and organ function. This includes building new tissue and repairing damaged tissue. ATP can also be stored to fulfill future energy demands. The remaining 60 percent of the energy released from catabolic reactions is given off as heat, which tissues and body fluids absorb. Structurally, ATP molecules consist of an adenine, a ribose, and three phosphate groups (Figure 24.2). The chemical bond between the second and third phosphate groups, termed a high-energy bond, represents the greatest source of energy in a cell. It is the first bond that catabolic enzymes break when cells require energy to do work. The products of this reaction are a molecule of adenosine diphosphate (ADP) and a lone phosphate group (Pi). ATP, ADP, and Pi are constantly being cycled through reactions that build ATP and store energy, and reactions that break down ATP and release energy. | chemistry | 0 |
In qualitative analysis, reagents are added to an unknown chemical mixture in order to induce what? | salinity scale | deflect electricity | time | precipitation | Selective precipitation can also be used in qualitative analysis. In this method, reagents are added to an unknown chemical mixture in order to induce precipitation. Certain reagents cause specific ions to precipitate out; therefore, the addition of the reagent can be used to determine whether the ion is present in the solution. | chemistry | 2 |
While climate change in earth history was due to natural processes, what is primarily to blame for recent global warming? | myopia | at the poles | gravel | human actions | Climate change in Earth history was due to natural processes. Recent global warming is due mainly to human actions. The burning of fossil fuels releases greenhouse gases into the air. This creates greater greenhouse effect and global warming. | geography | 0 |
What is the simplest life cycle? | information | diploid life cycle | Xerxes | haploid life cycle | The haploid life cycle ( Figure below ) is the simplest life cycle. It is found in many single-celled organisms. Organisms with a haploid life cycle spend the majority of their lives as haploid gametes. When the haploid gametes fuse, they form a diploid zygote. It quickly undergoes meiosis to produce more haploid gametes that repeat the life cycle. | biology | 2 |
What keeps the moon orbiting earth? | axial tilt | ending velocity | changing | gravity | Gravity keeps the Moon orbiting Earth. Gravity keeps the planets orbiting the Sun. | physics | 2 |
What are formed by the attraction between oppositely charged ions? | iron atom | chemistry table | bolts | ionic bonds | Ionic bonds are formed by the attraction between oppositely charged ions. | physics | 0 |
What produces hormones that directly regulate body processes? | pre-adolescence | Stavros smears | lymph glands | hypothalamus | The hypothalamus also produces hormones that directly regulate body processes. For example, it produces antidiuretic hormone. This hormone travels to the kidneys and stimulates them to conserve water by producing more concentrated urine. | biology | 1 |
Comparing anatomy, and characterizing the similarities and differences, provides evidence of what process? | molecules of cholesterol | climax community | visual diffusion | evolution | Take a close look at this gorilla hand. The similarities to a human hand are remarkable. Comparing anatomy, and characterizing the similarities and differences, provides evidence of evolution. | biology | 2 |
What is the second most abundant element in the earth's crust? | carbon | nitrogen | helium | silicon | What is this intricate orb? It is the greatly magnified skeleton of single-celled ocean organisms call radiolarian. The skeleton is made of an element that is extremely common on Earth. In fact, it is the second most abundant element in Earth’s crust. It is also one of the most common elements in the entire universe. What is this important element? Its name is silicon, and it belongs to a class of elements called metalloids. | chemistry | 3 |
Which kind of genetics approach involves mutating or deleting genes provides researchers with clues about gene function? | humans | they expand | brain plexus | reverse genetics | Watch this short video (http://openstaxcollege. org/l/transgenic) explaining how scientists create a transgenic animal. Although the classic methods of studying the function of genes began with a given phenotype and determined the genetic basis of that phenotype, modern techniques allow researchers to start at the DNA sequence level and ask: "What does this gene or DNA element do?" This technique, called reverse genetics, has resulted in reversing the classical genetic methodology. One example of this method is analogous to damaging a body part to determine its function. An insect that loses a wing cannot fly, which means that the wing’s function is flight. The classic genetic method compares insects that cannot fly with insects that can fly, and observes that the non-flying insects have lost wings. Similarly in a reverse genetics approach, mutating or deleting genes provides researchers with clues about gene function. Alternately, reverse genetics can be used to cause a gene to overexpress itself to determine what phenotypic effects may occur. | biology | 0 |
More than half of all known organisms are what? | concentration | surface species | cancerous cells | insects | The majority of arthropods are insects (Class Insecta). In fact, more than half of all known organisms are insects. There may be more than 10 million insect species in the world, although most of them have not yet been identified. In terms of their numbers and diversity, insects clearly are the dominant animals in the world. | biology | 0 |
For what purpose does liver use the excess carbohydrate? | local environment | addressing molecules | buds | to synthesize glycogen | Obesity With obesity at high rates in the United States, there is a public health focus on reducing obesity and associated health risks, which include diabetes, colon and breast cancer, and cardiovascular disease. How does the food consumed contribute to obesity? Fatty foods are calorie-dense, meaning that they have more calories per unit mass than carbohydrates or proteins. One gram of carbohydrates has four calories, one gram of protein has four calories, and one gram of fat has nine calories. Animals tend to seek lipid-rich food for their higher energy content. Greater amounts of food energy taken in than the body’s requirements will result in storage of the excess in fat deposits. Excess carbohydrate is used by the liver to synthesize glycogen. When glycogen stores are full, additional glucose is converted into fatty acids. These fatty acids are stored in adipose tissue cells—the fat cells in the mammalian body whose primary role is to store fat for later use. The rate of obesity among children is rapidly rising in the United States. To combat childhood obesity and ensure that children get a healthy start in life, in 2010 First Lady Michelle Obama launched the Let’s Move! campaign. The goal of this campaign is to educate parents and caregivers on providing healthy nutrition and encouraging active lifestyles in future generations. This program aims to involve the entire community, including parents, teachers, and healthcare providers to ensure that children have access to healthy foods—more fruits, vegetables, and whole grains—and consume fewer calories from processed foods. Another goal is to ensure that children get physical activity. With the increase in television viewing and stationary pursuits such as video games, sedentary lifestyles have become the norm. Visit www. letsmove. gov to learn more. | biology | 0 |
Saturn is made mostly of helium and what else? | cross-eye and blindness | go up | the wind cycle | hydrogen | Saturn’s composition is similar to Jupiter's. The planet is made mostly of hydrogen and helium. These elements are gases in the outer layers and liquids in the deeper layers. Saturn may also have a small solid core. Saturn's upper atmosphere has clouds in bands of different colors. These clouds rotate rapidly around the planet. But Saturn has fewer storms than Jupiter. Thunder and lightning have been seen in the storms on Saturn ( Figure below ). | physics | 0 |
What are alkenes organic compounds that contain one or more double or triple bonds between carbon atoms described as? | mucous earth metals | less pollution | temperature energy | unsaturated | Alkenes Organic compounds that contain one or more double or triple bonds between carbon atoms are described as unsaturated. You have likely heard of unsaturated fats. These are complex organic molecules with long chains of carbon atoms, which contain at least one double bond between carbon atoms. Unsaturated hydrocarbon molecules that contain one or more double bonds are called alkenes. Carbon atoms linked by a double bond are bound together by two bonds, one σ bond and one π bond. Double and triple bonds give rise to a different geometry around the carbon atom that participates in them, leading to important differences in molecular shape and properties. The differing geometries are responsible for the different properties of unsaturated versus saturated fats. Ethene, C2H4, is the simplest alkene. Each carbon atom in ethene, commonly called ethylene, has a trigonal planar structure. The second member of the series is propene (propylene) (Figure 20.7); the butene isomers follow in the series. Four carbon atoms in the chain of butene allows for the formation of isomers based on the position of the double bond, as well as a new form of isomerism. | chemistry | 2 |
Electrons in covalent compounds are shared between the two atoms, unlike the case in what type of bonds? | soluble bonds | horizontal bonds | organism acids | ionic bonds | The two materials do have at least one thing in common. The atoms in the materials are held together by covalent bonds. These bonds consist of electrons shared between two or more atoms. Unlike ionic bonds, where electrons are either lost or gained by an atom to form charged ions, electrons in covalent compounds are shared between the two atoms, giving rise to properties that are quite different from those seen in ionic materials. | chemistry | 2 |
What is the resistance of a liquid to flow called? | negative energy | turbulence | larger atomic size | viscosity | Viscosity (η) is the resistance of a liquid to flow. Some liquids, such as gasoline, ethanol, and water, flow very readily and hence have a low viscosity. Others, such as motor oil, molasses, and maple syrup, flow very slowly and have a high viscosity. The two most common methods for evaluating the viscosity of a liquid are (1) to measure the time it takes for a quantity of liquid to flow through a narrow vertical tube and (2) to measure the time it takes steel balls to fall through a given volume of the liquid. The higher the viscosity, the slower the liquid flows through the tube and the steel balls fall. Viscosity is expressed in units of the poise (mPa·s); the higher the number, the higher the viscosity. The viscosities of some representative liquids are listed in Table 11.4 "Surface Tension, Viscosity, Vapor Pressure (at 25°C Unless Otherwise Indicated), and Normal Boiling Points of Common Liquids" and show a correlation between viscosity and intermolecular forces. Because a liquid can flow only if the molecules can move past one another with minimal resistance, strong intermolecular attractive forces make it more difficult for molecules to move with respect to one another. The addition of a second hydroxyl group to ethanol, for example, which produces ethylene glycol (HOCH2CH2OH), increases the viscosity 15-fold. This effect is due to the increased number of hydrogen bonds that can form between hydroxyl groups in adjacent molecules, resulting in dramatically stronger intermolecular attractive forces. | physics | 2 |
The mass of atoms is based on the number of protons and neutrons in what? | components | a rope | periodic point | nucleus | Atoms have a mass that is based largely on the number of protons and neutrons in their nucleus. | physics | 2 |
Where do polychaete worms live? | farthest | cataclysmic time scale | canopy | the ocean floor | Annelids called polychaete worms live on the ocean floor. They may be filter feeders, predators, or scavengers. The amazing feather duster worm in Figure below is a polychaete that has a fan-like crown of tentacles for filter feeding. | geography | 3 |
What is the study of how and why plants and animals live where they do? | Thyroid gland | geomorphology | intelligence | biogeography | Biogeography is the study of how and why plants and animals live where they do. It provides more evidence for evolution. Let’s consider the camel family as an example. | biology | 1 |
Muscles that position the pectoral girdle are located either on the anterior thorax or on this? | intuitive | posterior thorax | some earthworms | posterior thorax | Muscles That Position the Pectoral Girdle Muscles that position the pectoral girdle are located either on the anterior thorax or on the posterior thorax (Figure 11.22 and Table 11.8). The anterior muscles include the subclavius, pectoralis minor, and serratus anterior. The posterior muscles include the trapezius, rhomboid major, and rhomboid minor. When the rhomboids are contracted, your scapula moves medially, which can pull the shoulder and upper limb posteriorly. | biology | 1 |
What are the two major types of seed plants called? | pearl | excitatory | inhibition | gymnosperms and angiosperms | The two major types of seed plants are the gymnosperms (seeds in cones) and angiosperms (seeds in ovaries of flowers). Figure below shows how the seeds of gymnosperms and angiosperms differ. Do you see the main difference between the two seeds? The angiosperm seed is surrounded by an ovary . | biology | 1 |
What do we call the energy-rich product of photosynthesis? | respiratory muscle | tissues | sugar | glucose | Glucose is the energy-rich product of photosynthesis, a universal food for life. It is also the primary form in which your bloodstream delivers energy to every cell in your body. | biology | 1 |
How is oxygen transferred into the bloodstream? | the ecosystem | powdered | wattage | simple diffusion | The oxygen enters the bloodstream from the alveoli , tiny sacs in the lungs where gas exchange takes place ( Figure below ). The transfer of oxygen into the blood is through simple diffusion. | physics | 0 |
Ringworm and athlete's foot are human diseases caused by what simple organisms? | viruses | dna ( trigraph acid ) and rna ( ribonucleic acid ) | insects | fungi | Fungi are simple eukaryotic organisms that consist of one or more cells. They include mushrooms and yeasts. Human diseases caused by fungi include ringworm and athlete’s foot. Both are skin diseases that are not usually serious. A ringworm infection is pictured below ( Figure below ). A more serious fungus disease is histoplasmosis. It is a lung infection. Though fungal infections can be annoying, they are rarely as serious or deadly as bacterial or viral infections. | biology | 3 |
What is the measure of the change in the velocity of a moving object called? | pressurization | biochemistry | cold gas | acceleration | A car’s gas pedal, like the one in Figure below , is sometimes called the accelerator. That’s because it controls the acceleration of the car. Pressing down on the gas pedal gives the car more gas and causes the car to speed up. Letting up on the gas pedal gives the car less gas and causes the car to slow down. Whenever an object speeds up, slows down, or changes direction, it accelerates. Acceleration is a measure of the change in velocity of a moving object. Acceleration occurs whenever an object is acted upon by an unbalanced force. | physics | 1 |
What is the usual treatment for acute bronchitis? | rough tissue | individuals | feedback loops | antibiotics | Bronchitis is an inflammation of the bronchi, the air passages that conduct air into the lungs. The bronchi become red and swollen with infection. Acute bronchitis is usually caused by viruses or bacteria, and may last several days or weeks. It is characterized by a cough that produces phlegm, or mucus. Symptoms include shortness of breath and wheezing. Acute bronchitis is usually treated with antibiotics. | biology | 2 |
What are generally divided into prosimian and non-prosimian? | insects | mass capacity | rusting | primates | Primates are generally divided into prosimian and non-prosimian primates. | physics | 1 |
The creation and destruction of oceanic crust is the reason what moves? | oceans | animals | propagate | continents | In some places, the oceanic crust comes up to a continent. The moving crust pushes that continent away from the ridge axis as well. If the moving oceanic crust reaches a deep sea trench, the crust sinks into the mantle. The creation and destruction of oceanic crust is the reason that continents move. | physics | 2 |
What is the concept by which two species within the same area to coexist by adapting by developing different specializations? | character concept | waste | adaptive radiation | character displacement | Looking at different types of competition, ecologists developed the competitive exclusion principle . The principle states that species less suited to compete for resources will either adapt, move from the area, or die out. In order for two species within the same area to coexist, they may adapt by developing different specializations. This is known as character displacement . An example of character displacement is when different birds adapt to eating different types of food. They can develop different types of bills, like Darwin’s Finches ( Figure below ). Therefore, competition for resources within and between species plays an important role in evolution through natural selection . | biology | 1 |
A turbine that spins a generator will produce? | magnetic fields | Louis Pasteur | light | electricity | You can follow the operation of an electricity-generating fission reactor in the image above. The reactor core is submerged in a pool of water. The heat from the fission reaction heats the water, which is pumped into a heat exchange container. There the heated water boils the water in the heat exchanger. The produced steam is forced through a turbine that spins a generator and produces electricity. After the water passes through the turbine, it is condensed back to liquid water and pumped back to the heat exchanger. | physics | 2 |
Meiosis in the sporophyte produces haploid cells called what? | Disperse Myriapoda | fibers | moderation | spores | biology | 1 |
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In this type of reaction, an element replaces another element in a compound, and the element is in any state of matter but is not an ion? | carbon remediation | a catalyst | saline content | single-replacement reaction | A single-replacement reaction is one in which an element replaces another element in a compound. An element is in either the solid, liquid, or gas state and is not an ion. The example below shows the reaction of solid magnesium metal with aqueous silver nitrate to form aqueous magnesium nitrate and silver metal. | chemistry | 0 |
What are the two distinct types of cells found in the animal kingdom? | during meiosis | motor cortex | water and minerals | prokaryotes and eukaryotes | biology | 1 |
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What category of elements are chacterized by their ability to reflect light, called luster, their high electrical and thermal conductivity, their high heat capacity, and their malleability and ductility? | critical point | halogens | nonmetals | metals | Metallic Solids Metals are characterized by their ability to reflect light, called luster, their high electrical and thermal conductivity, their high heat capacity, and their malleability and ductility. Every lattice point in a pure metallic element is occupied by an atom of the same metal. The packing efficiency in metallic crystals tends to be high, so the resulting metallic solids are dense, with each atom having as many as 12 nearest neighbors. Bonding in metallic solids is quite different from the bonding in the other kinds of solids we have discussed. Because all the atoms are the same, there can be no ionic bonding, yet metals always contain too few electrons or valence orbitals to form covalent bonds with each of their neighbors. Instead, the valence electrons are delocalized throughout the crystal, providing a strong cohesive force that holds the metal atoms together. | physics | 3 |
Angiosperms are also known as what? | dead plants | dry plants | kidney | flowering plants | Introduction Plants are as essential to human existence as land, water, and air. Without plants, our day-to-day lives would be impossible because without oxygen from photosynthesis, aerobic life cannot be sustained. From providing food and shelter to serving as a source of medicines, oils, perfumes, and industrial products, plants provide humans with numerous valuable resources. When you think of plants, most of the organisms that come to mind are vascular plants. These plants have tissues that conduct food and water, and they have seeds. Seed plants are divided into gymnosperms and angiosperms. Gymnosperms include the needle-leaved conifers—spruce, fir, and pine—as well as less familiar plants, such as ginkgos and cycads. Their seeds are not enclosed by a fleshy fruit. Angiosperms, also called flowering plants, constitute the majority of seed plants. They include broadleaved trees (such as maple, oak, and elm), vegetables (such as potatoes, lettuce, and carrots), grasses, and plants known for the beauty of their flowers (roses, irises, and daffodils, for example). While individual plant species are unique, all share a common structure: a plant body consisting of stems, roots, and leaves. They all transport water, minerals, and sugars produced through photosynthesis through the plant body in a similar manner. All plant species also respond to environmental factors, such as light, gravity, competition, temperature, and predation. | biology | 3 |
An estimated 100 trillion of these live in the gut of an average person? | nerve muscle | linnaean system | slow aging | bacteria | It is estimated that 100 trillion bacteria live in the gut. This is more than the human cells that make up you. It has also been estimated that there are more bacteria in your mouth than people on the planet. There are over 7 billion people on the planet. | biology | 0 |
The ability to regulate what, which is possessed by mammals, was an advantage as earth’s climate went through sudden and dramatic changes? | central tendency | single helix | optimal pressure | body temperature | Mammals have the ability to regulate body temperature. This is an advantage, as Earth’s climate went through sudden and dramatic changes. Mastodons, saber tooth tigers, hoofed mammals, whales, primates and eventually humans all lived during the Cenozoic Era ( Figure below ). | biology | 0 |
What is the term for very large arrays of tandemly repeating, non-coding dna? | meat | mechanically | serotonin and glucagon | satellite dna | The majority of the human genome is non-coding sequence. These sequences include regulatory sequences, and DNA with unknown functions. These sequences include tandem repeat elements known as satellite DNA , and transposons. Satellite DNA consists of very large arrays of tandemly repeating, non-coding DNA. The repeating units can be just a single base (a mono nucleotide repeat), two bases (a dinucleotide repeat), three bases (a trinucleotide repeat) or a much larger repeating unit. Some repeating units are several thousand base pairs long, and the total size of a satellite DNA segment can be several megabases without interruption. | biology | 0 |
What kind of map can show the features of the bottom of a body of water? | articulation | acids | forests | bathymetric | Oceanographers use bathymetric maps to show the features of the bottom of a body of water. | geography | 0 |
What evolved, adapted response to resource availability is the long-range seasonal movement of animals? | Turner syndrome | motility | glomeruli | migration | Migration Migration is the long-range seasonal movement of animals. It is an evolved, adapted response to variation in resource availability, and it is a common phenomenon found in all major groups of animals. Birds fly south for the winter to get to warmer climates with sufficient food, and salmon migrate to their spawning grounds. The popular 2005 documentary March of the Penguins followed the 62-mile migration of emperor penguins through Antarctica to bring food back to their breeding site and to their young. Wildebeests (Figure 45.35) migrate over 1800 miles each year in search of new grasslands. | biology | 1 |