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The two general types of reproduction are sexual and what? | unisexual | primitive | bisexual | asexual | Reproduction is how organisms produce offspring. The ability to reproduce is a characteristic of all living things. In some species, all the offspring are genetically identical to the parent. In other species, each offspring is genetically unique. Look at the kittens in Figure below . They are brothers and sisters, but they are all different from each other. Why does this happen in some species but not others? It’s because there are two types of reproduction. Reproduction can be sexual or asexual. |
Acid rain is corrosive rain caused by rainwater falling to the ground through which gas? | essential dioxide | sulfide dioxide | carbon dioxide | sulfur dioxide | Sulfur enters the ocean in runoff from land, from atmospheric fallout, and from underwater geothermal vents. Some ecosystems rely on chemoautotrophs using sulfur as a biological energy source. This sulfur then supports marine ecosystems in the form of sulfates. Human activities have played a major role in altering the balance of the global sulfur cycle. The burning of large quantities of fossil fuels, especially from coal, releases larger amounts of hydrogen sulfide gas into the atmosphere. As rain falls through this gas, it creates the phenomenon known as acid rain, which damages the natural environment by lowering the pH of lakes, thus killing many of the resident plants and animals. Acid rain is corrosive rain caused by rainwater falling to the ground through sulfur dioxide gas, turning it into weak sulfuric acid, which causes damage to aquatic ecosystems. Acid rain also affects the man-made environment through the chemical degradation of buildings. For example, many marble monuments, such as the Lincoln Memorial in Washington, DC, have suffered significant damage from acid rain over the years. These examples show the wide-ranging effects of human activities on our environment and the challenges that remain for our future. |
What is the net force when two forces act in the same direction? | group of forces | number of the forces | arguing forces | sum of the forces | Two forces may act on an object in the same direction. You can see an example of this in Figure below . After the man on the left lifts up the couch, he will push the couch to the right with a force of 25 newtons. At the same time, the man to the right is pulling the couch to the right with a force of 20 newtons. When two forces act in the same direction, the net force is equal to the sum of the forces. This always results in a stronger force than either of the individual forces alone. In this case, the net force on the couch is 45 newtons to the right, so the couch will move to the right. |
What hypothesis states that the biosphere is its own living organism | small world theory | the seager hypothesis | Big Bang theory | the gaia hypothesis | The Gaia hypothesis states that the biosphere is its own living organism. |
The planet neptune has strange dark spots that sometimes appear on its surface? what are these spots? | black holes | seas | earthquakes | storms | Neptune is very cold and has very strong winds. It had a large dark spot that disappeared. Another dark spot appeared on another part of the planet. These dark spots are storms in Neptune’s atmosphere. |
The thalamus acts as a gateway to and from what? | spine | pons | medulla oblongata | cortex | The thalamus acts as a gateway to and from the cortex. It receives sensory and motor inputs from the body and also receives feedback from the cortex. This feedback mechanism can modulate conscious awareness of sensory and motor inputs depending on the attention and arousal state of the animal. The thalamus helps regulate consciousness, arousal, and sleep states. Below the thalamus is the hypothalamus. The hypothalamus controls the endocrine system by sending signals to the pituitary gland. Among other functions, the hypothalamus is the body’s thermostat—it makes sure the body temperature is kept at appropriate levels. Neurons within the hypothalamus also regulate circadian rhythms, sometimes called sleep cycles. The limbic system is a connected set of structures that regulates emotion, as well as behaviors related to fear and motivation. It plays a role in memory formation and includes parts of the thalamus and hypothalamus as well as the hippocampus. One important structure within the limbic system is a temporal lobe structure called the amygdala. The two amygdala (one on each side) are important both for the sensation of fear and for recognizing fearful faces. The cerebellum (cerebellum = “little brain”) sits at the base of the brain on top of the brainstem. The cerebellum controls balance and aids in coordinating movement and learning new motor tasks. The cerebellum of birds is large compared to other vertebrates because of the coordination required by flight. The brainstem connects the rest of the brain with the spinal cord and regulates some of the most important and basic functions of the nervous system including breathing, swallowing, digestion, sleeping, walking, and sensory and motor information integration. |
When describing motion, what factor is just as important as distance? | pressure | momentum | velocity | direction | Direction is just as important as distance in describing motion. For example, if Mia told a friend how to reach the post office from her house, she couldn’t just say, "go 3 kilometers. " The friend might end up at the park instead of the post office. Mia would have to be more specific. She could say, "go west for 2 kilometers and then go north for 1 kilometer. " When both distance and direction are considered, motion is a vector. A vector is a quantity that includes both size and direction. A vector is represented by an arrow. The length of the arrow represents distance. The way the arrow points shows direction. The red arrows in Figure above are vectors for Mia’s route to the school and post office. If you want to learn more about vectors, watch the videos at these URLs:. |
What often relies on cooperation between the motor and autonomic nervous systems? | hypothalamus | ketosis | thermoregulation | homeostasis | |
What nerves are connected to the spinal cord? | superior nerves | primary nerves | posterior nerves | spinal nerves | Spinal Nerves The nerves connected to the spinal cord are the spinal nerves. The arrangement of these nerves is much more regular than that of the cranial nerves. All of the spinal nerves are combined sensory and motor axons that separate into two nerve roots. The sensory axons enter the spinal cord as the dorsal nerve root. The motor fibers, both somatic and autonomic, emerge as the ventral nerve root. The dorsal root ganglion for each nerve is an enlargement of the spinal nerve. There are 31 spinal nerves, named for the level of the spinal cord at which each one emerges. There are eight pairs of cervical nerves designated C1 to C8, twelve thoracic nerves designated T1 to T12, five pairs of lumbar nerves designated L1 to L5, five pairs of sacral nerves designated S1 to S5, and one pair of coccygeal nerves. The nerves are numbered from the superior to inferior positions, and each emerges from the vertebral column through the intervertebral foramen at its level. The first nerve, C1, emerges between the first cervical vertebra and the occipital bone. The second nerve, C2, emerges between the first and second cervical vertebrae. The same occurs for C3 to C7, but C8 emerges between the seventh cervical vertebra and the first thoracic vertebra. For the thoracic and lumbar nerves, each one emerges between the vertebra that has the same designation and the next vertebra in the column. The sacral nerves emerge from the sacral foramina along the length of that unique vertebra. Spinal nerves extend outward from the vertebral column to enervate the periphery. The nerves in the periphery are not straight continuations of the spinal nerves, but rather the reorganization of the axons in those nerves to follow different courses. Axons from different spinal nerves will come together into a systemic nerve. This occurs at four places along the length of the vertebral column, each identified as a nerve plexus, whereas the other spinal nerves directly correspond to nerves at their respective levels. In this instance, the word plexus is used to describe networks of nerve fibers with no associated cell bodies. |
What source of water pollution picks up chemicals from the ground with water and carries them to bodies of water? | sediment | fertilizer | erosion | runoff | Water pollution comes from many sources. One of the biggest sources is runoff. Runoff picks up chemicals such as fertilizer from agricultural fields, lawns, and golf courses. It carries the chemicals to bodies of water. The added nutrients from fertilizer often cause excessive growth of algae, creating algal blooms (see Figure below ). The algae use up oxygen in the water so that other aquatic organisms cannot survive. This has occurred over large areas of the ocean, creating dead zones , where low oxygen levels have killed all ocean life. A very large dead zone exists in the Gulf of Mexico. Measures that can help prevent these problems include cutting down on fertilizer use. Preserving wetlands also helps because wetlands filter runoff. |
Where do all cells come from? | busy cells | large cells | dying cells | pre-existing cells | All cells come from pre-existing cells. |
What is the term for learning from past experiences and reasoning? | experimental learning | logical learning | consequence learning | insight learning | Insight learning is learning from past experiences and reasoning. It generally involves coming up with new ways to solve problems. Insight learning generally happens quickly. An animal has a sudden flash of insight. Insight learning requires relatively great intelligence. Human beings use insight learning more than any other species. They have used it to invent the wheel to land astronauts on the moon. |
Science is the process of knowing about the natural universe through observation and this? | experimental | Test | variation | experiment | Chemistry is a branch of science. Although science itself is difficult to define exactly, the following definition can serve as starting point. Science is the process of knowing about the natural universe through observation and experiment. Science is not the only process of knowing (e. , the ancient Greeks simply sat and thought), but it has evolved over more than 350 years into the best process that humanity has devised to date to learn about the universe around us. The process of science is usually stated as the scientific method, which is rather naïvely described as follows: (1) state a hypothesis, (2) test the hypothesis, and (3) refine the hypothesis. Actually, however, the process is not that simple. (For example, I don’t go into my lab every day and exclaim, “I am going to state a hypothesis today and spend the day testing it!”) The process is not that simple because science and scientists have a body of knowledge that has already been identified as coming from the highest level of understanding, and most scientists build from that body of knowledge. An educated guess about how the natural universe works is called a hypothesis. A scientist who is familiar with how part of the natural universe works—say, a chemist—is interested in furthering that knowledge. That person makes a reasonable guess—a hypothesis—that is designed to see if the universe works in a new way as well. Here’s an example of a hypothesis: “if I mix one part of hydrogen with one part of oxygen, I can make a substance that contains both elements. ” Most good hypotheses are grounded in previously understood knowledge and represent a testable extension of that knowledge. The scientist then devises ways to test if that guess is or is not correct. That is, the scientist plans experiments. Experiments are tests of the natural Saylor URL: http://www. saylor. org/books. |
What type of plant keeps it green leaves year-round? | cactus | deciduous | conifer | evergreen plant | An evergreen plant keeps its green leaves year-round. It may have needle-like leaves to reduce water loss. |
What are reactions that can occur only in one direction called? | critical | permanent | instantaneous | irreversible | Some chemical reactions can occur in only one direction. These reactions are called irreversible reactions. The reactants can change to the products, but the products cannot change back to the reactants. These reactions are like making a cake. The ingredients of a cake—such as eggs and flour—are the reactants. They are mixed together and baked to form the cake, which is the product (see Figure below ). The cake can’t be “unbaked” and “unmixed” to change it back to the raw eggs, flour, and other ingredients. So making a cake is irreversible. |
What is the diffusion of water molecules across a semipermeable membrane? | active transport | organelle motion | electrolysis | osmosis | Osmosis is the diffusion of water molecules across a semipermeable membrane and down a concentration gradient. They can move into or out of a cell, depending on the concentration of the solute. |
What forms when there is a difference in temperature between the land and the air? | sandstorms | smoke | tsunamis | fog | Fog forms when there is a difference in temperature between the land and the air. |
What domain-level category of cells can contain more than 1000 times the dna found in a typical bacterial cell? | genetic | chromosomes | mutations | eukaryotic | Figure 11.35 (a) Capillary action depends on the radius of a tube. The smaller the tube, the greater the height reached. The height is negligible for large-radius tubes. (b) A denser fluid in the same tube rises to a smaller height, all other factors being the same. |
What gas is released by burning of fossil fuels and contributes to global warming? | helium | nitrous oxide | hydrogen | carbon dioxide | Using fossil fuels affects the environment in a variety of ways. There are impacts to the environment when we extract these resources. Burning these fuels causes air pollution. These fuels release carbon dioxide, which is a major factor in global warming ( Figure below ). |
A major disturbance in what results in an episode of severe weather called a storm? | the ozone layer | the oceans | the core | the atmosphere | A storm is an episode of severe weather. It is caused by a major disturbance in the atmosphere. Types of storms include thunderstorms, tornadoes, and hurricanes. |
Bone marrow, the thymus gland, the spleen, and the tonsils are organs in what body system? | reproductive system | skeletal system | nervous system | immune system | Immune system organs include bone marrow, the thymus gland, the spleen, and the tonsils. Each organ has a different job in the immune system. |
What term refers to the balance, or equilibrium, within the cell or a body, and an organism’s ability to keep a constant internal environment? | consciousness | metabolism | ketosis | homeostasis | Homeostasis refers to the balance, or equilibrium, within the cell or a body. It is an organism’s ability to keep a constant internal environment. Keeping a stable internal environment requires constant adjustments as conditions change inside and outside the cell. The adjusting of systems within a cell is called homeostatic regulation. Because the internal and external environments of a cell are constantly changing, adjustments must be made continuously to stay at or near the set point (the normal level or range). Homeostasis is a dynamic equilibrium rather than an unchanging state. The cellular processes discussed in both the Diffusion and Active Transport concepts all play an important role in homeostatic regulation. You will learn more about homeostasis in other concepts. |
Atoms of different elements can combine in simple whole number ratios to form what? | combinations | mixtures | carbon compounds | chemical compounds | Atoms of different elements can combine in simple whole number ratios to form chemical compounds. |
What blood component serves both structural and molecular functions in blood clotting? | proteins | molecules | plasma | platelets | |
What type of reproduction begins when an egg and sperm combine? | asexual reproduction | natural reproduction | regular reproduction | sexual reproduction | 18.1 How Animals Reproduce Reproduction may be asexual when one individual produces genetically identical offspring, or sexual when the genetic material from two individuals is combined to produce genetically diverse offspring. Asexual reproduction in animals occurs through fission, budding, fragmentation, and parthenogenesis. Sexual reproduction may involve fertilization inside the body or in the external environment. A species may have separate sexes or combined sexes; when the sexes are combined they may be expressed at different times in the life cycle. The sex of an individual may be determined by various chromosomal systems or environmental factors such as temperature. Sexual reproduction starts with the combination of a sperm and an egg in a process called fertilization. This can occur either outside the bodies or inside the female. The method of fertilization varies among animals. Some species release the egg and sperm into the environment, some species retain the egg and receive the sperm into the female body and then expel the developing embryo covered with shell, while still other species retain the developing offspring throughout the gestation period. |
What are long chains of amino acids? | cells | lipids | Fatty Acid Chains | proteins | The reverse reaction (amide hydrolysis) is very useful in the study of protein structure. Proteins are long chains of amino acids (each amino acid contains an amine group and a carboxyl group, both attached to a central carbon atom). The amino acids are linked together by amide bonds to form the long protein chain. One of the techniques for looking at protein structure is to break those amide linkages so we can learn the identity of the amino acids in the chain. We do this through a hydrolysis reaction:. |
What phase exists when all the water in a container has physical properties intermediate between those of the gaseous and liquid states? | impregnation fluid | stationary fluid | hydrothermal fluid | supercritical fluid | Supercritical Fluids If we place a sample of water in a sealed container at 25 °C, remove the air, and let the vaporization-condensation equilibrium establish itself, we are left with a mixture of liquid water and water vapor at a pressure of 0.03 atm. A distinct boundary between the more dense liquid and the less dense gas is clearly observed. As we increase the temperature, the pressure of the water vapor increases, as described by the liquid-gas curve in the phase diagram for water (Figure 10.31), and a two-phase equilibrium of liquid and gaseous phases remains. At a temperature of 374 °C, the vapor pressure has risen to 218 atm, and any further increase in temperature results in the disappearance of the boundary between liquid and vapor phases. All of the water in the container is now present in a single phase whose physical properties are intermediate between those of the gaseous and liquid states. This phase of matter is called a supercritical fluid, and the temperature and pressure above which this phase exists is the critical point (Figure 10.35). Above its critical temperature, a gas cannot be liquefied no matter how much pressure is applied. The pressure required to liquefy a gas at its critical temperature is called the critical pressure. The critical temperatures and critical pressures of some common substances are given in Table 10.3. Substance. |
What do you call the movement of a substance from an area of a higher amount toward an area of lower amount? | precipitation | filtration | extraction | diffusion | Diffusion is the movement of a substance from an area of a higher amount toward an area of lower amount. A concentration gradient initially exists across the cell membrane. Equilibrium is reached when there is an equal amount of the substance on both sides of the membrane. |
Each myofibril is made up of two types of proteins, called actin and what? | Fatty Acid | dynein | elongation | myosin | Each myofibril is made up of two types of proteins, called actin and myosin. These proteins form thread-like filaments. |
If the experimental value is less than the accepted value, the error is what? | caused | positive | effective | negative | If the experimental value is less than the accepted value, the error is negative. If the experimental value is larger than the accepted value, the error is positive. Often, error is reported as the absolute value of the difference in order to avoid the confusion of a negative error. The percent error is the absolute value of the error divided by the accepted value and multiplied by 100%. |
According to which process, sublevels and orbitals are filled with electrons in order of increasing energy? | particle dynamics | Schrodinger's cat | hausen | aufbau | According to the Aufbau process, sublevels and orbitals are filled with electrons in order of increasing energy. Since the s sublevel consists of just one orbital, the second electron simply pairs up with the first electron as in helium. The next element is lithium and necessitates the use of the next available sublevel, the 2 s . |
The roughness of interacting surfaces and the magnitude of force pushing one object onto another are two factors related to what force? | temperature | energy | tension | friction | The force of friction between these two blocks is related to two factors. The first factor is the roughness of the surfaces that are interacting, which is called the coefficient of friction , (Greek letter mu). The second factor is the magnitude of the force pushing the top block down onto the lower block. It is reasonable that the more forcefully the blocks are pushed together, the more difficult it will be for one to slide over the other. The force pushing these blocks together is the result of gravity acting on the top block and pressing it against the bottom block, which resists the weight with an equal and opposite force called the normal force . The force of friction can be calculated by. |
How many types of leptons are there? | twelve | nine | two | six | There are also six types of leptons, including electrons. Leptons have an electric charge of either -1 or 0. Electrons, for example, have a charge of -1. Leptons have mass, although the mass of electrons is extremely small. |
Plants, algae and bacteria are all examples of what type of organism? | skeletal | microbes | unicellular | photosynthetic | Photosynthetic organisms include plants, algae, and some bacteria. |
What forms after air cools below its dew point? | plasma | sleet | smoke | fog | Advection fog is famous in San Francisco, California. Warm, moist air comes in from the Pacific Ocean. The air blows over the cold California current. When the air cools below its dew point, fog forms. Sea breezes bring the fog onshore. |
In hornworts, the horns are the sporophytes that rise up from what? | the breaza gametophyte | the roots | the polyol gametophyte | the leaflike gametophyte | Jason Hollinger. In hornworts, the horns are the sporophytes that rise up from the leaflike gametophyte . CC BY 2.0. |
What generally sets the direction that technology takes? | random chance | local animals | local weather | problems of society | The goal of technology is to solve people’s problems. Therefore, the problems of society generally set the direction that technology takes. Technology, in turn, affects society. It may make people’s lives easier or healthier. Two examples are described in Figure below . |
Living things that feed on others are generally known as what? | producers | customers | isolators | consumers | |
What is an isotope that is radioactive called? | radionuclides | isotopes | matured isotope | radioisotopes | Many elements have one or more isotopes that are radioactive. These isotopes are called radioisotopes. An example of a radioisotope is carbon-14. |
What is a compound that can form ions when it dissolves in water called? | isolate | sulfate | compound | electrolyte | acid will form a homogeneous solution with water. (In fact, the solubility of both butanol and pentanoic acid in water is quite low, only about 3 g per 100 g water at 25°C. ) 10. An electrolyte is any compound that can form ions when it dissolves in water. When a strong electrolyte dissolves in water, it dissociates completely to give the constituent ions. In contrast, when a weak electrolyte dissolves in water, it produces relatively few ions in solution. |
When using a generator, we are transforming what energy into what energy? | mechanical into thermal | magnetic into kinetic | thermal into radioactive | kinetic into electrical | Generators may be set up to produce either direct or alternating current. Generators in cars and most power plants produce alternating current. Regardless of the type of current, all generators change kinetic energy to electrical energy. |
What kind of resource is soil? | viable | nonrenewable | finite | renewable | Soil is a renewable resource. Sometimes it is lost faster than it can be replaced. |
What is the term for the stalk connecting a leaf to a stem? | base | cuticle | blades | petiole | Figure 30.4 Leaves are attached to the plant stem at areas called nodes. An internode is the stem region between two nodes. The petiole is the stalk connecting the leaf to the stem. The leaves just above the nodes arose from axillary buds. |
What are the specialized cells within the brain called? | protons | ions | electrons | neurons | Figure 3.9 (a) A typical human brain weighs about 1.5 kg and occupies a volume of roughly 1.1 L. (b) Information is transmitted in brain tissue and throughout the central nervous system by specialized cells called neurons (micrograph shows cells at 1600× magnification). Specialized cells called neurons transmit information between different parts of the central nervous system by way of electrical and chemical signals. Chemical signaling occurs at the interface between different neurons. |
What stimulates the production of milk by the mammary glands following childbirth? | melanin | progesterone | estrogen | prolactin | (PRL) in females. Prolactin stimulates the production of milk by the mammary glands following childbirth. Prolactin levels are regulated by the hypothalamic hormones prolactin-releasing hormone (PRH) and prolactin-inhibiting hormone (PIH) which is now known to be dopamine. PRH stimulates the release of prolactin and PIH inhibits it. The posterior pituitary releases the hormone oxytocin, which stimulates contractions during childbirth. The uterine smooth muscles are not very sensitive to oxytocin until late in pregnancy when the number of oxytocin receptors in the uterus peaks. Stretching of tissues in the uterus and vagina stimulates oxytocin release in childbirth. Contractions increase in intensity as blood levels of oxytocin rise until the birth is complete. 22 Hormone production and release are primarily controlled by negative feedback. In negative feedback systems, a stimulus causes the release of a substance whose effects then inhibit further release. In this way, the concentration of hormones in blood is maintained within a narrow range. For example, the anterior pituitary signals the thyroid to release thyroid hormones. Increasing levels of these hormones in the blood then feed back to the hypothalamus and anterior pituitary to inhibit further signaling to the thyroid gland. 24 The main mineralocorticoid is aldosterone, which regulates the concentration of ions in urine, sweat, and saliva. Aldosterone release from the adrenal cortex is stimulated by a decrease in blood concentrations of sodium ions, blood volume, or blood pressure, or an increase in blood potassium levels. |
In vascular plants, the sporophyte generation is what? | resting | non-existant | submissive | dominant | In vascular plants, the sporophyte generation is dominant. |
What organ system transports blood through the body and to and from the lungs? | nervous | metabolism | digestive | circulatory | in animals but also in plants. An organ system is a higher level of organization that consists of functionally related organs. Mammals have many organ systems. For instance, the circulatory system transports blood through the body and to and from the lungs; it includes organs such as the heart and blood vessels. Organisms are individual living entities. For example, each tree in a forest is an organism. Single-celled prokaryotes and single-celled eukaryotes are also considered organisms and are typically referred to as microorganisms. All the individuals of a species living within a specific area are collectively called a population. For example, a forest may include many pine trees. All of these pine trees represent the population of pine trees in this forest. Different populations may live in the same specific area. For example, the forest with the pine trees includes populations of flowering plants and also insects and microbial populations. A community is the sum of populations inhabiting a particular area. For instance, all of the trees, flowers, insects, and other populations in a forest form the forest’s community. The forest itself is an ecosystem. An ecosystem consists of all the living things in a particular area together with the abiotic, non-living parts of that environment such as nitrogen in the soil or rain water. At the highest level of organization (Figure 1.16), the biosphere is the collection of all ecosystems, and it represents the zones of life on earth. It includes land, water, and even the atmosphere to a certain extent. |
"cardio" has become slang for what type of exercise that raises your heart rate for an extended amount of time? | anaerobic | cyclical | kinetic | aerobic | "Cardio" has become slang for aerobic exercise that raises your heart rate for an extended amount of time. Cardio can include biking, running, or swimming. Can you guess one of the main organs of the cardiovascular system? Yes, your heart. |
How many protons do all atoms of a particular element have in their nuclei? | zero | varying number | three | same number | |
One of the five fundamental conservation laws in the universe refers to conservation of what, which is the product of mass and velocity? | light | fluid | energy | momentum | The universe has many remarkable qualities, among them a rather beautiful symmetry: the total amount of motion in the universe balances out … always. This law only makes sense if we measure “motion” in a specific way: as the product of mass and velocity. This product, called momentum , can be exchanged from one object to another in a collision. The rapidity with which momentum is exchanged over time is determined by the forces involved in the collision. Conservation of momentum is one of the five fundamental conservation laws in the universe. The other four are conservation of energy, angular momentum, charge conservation and CPT conservation. |
Copper oxide is a result of what two substances mixing? | crystal and oxygen | copper and gas | metal and oxygen | copper and oxygen | |
The process of getting oxygen into the body and releasing carbon dioxide is called? | precipitation | osmosis | persperation | respiration | The process of getting oxygen into the body and releasing carbon dioxide is called respiration . Sometimes breathing is called respiration, but there is much more to respiration than just breathing. Breathing is only the movement of oxygen into the body and carbon dioxide out of the body. The process of respiration also includes the exchange of oxygen and carbon dioxide between the blood and the cells of the body. |
Someone who believes something despite the evidence is referred to by what term that references a false belief about our planet? | solid - earther | geocentric-earther | conspiracy theorist | flat-earther | Flat-earther is a term used to describe someone who believes something despite the evidence. Or who does not believe something despite the evidence. There are actually people who believe that Earth is flat. They say that satellite photos are faked. They believe that the Apollo Moon landings were faked. But there are very few people alive today who actually believe that Earth is flat. There are, however, plenty of people who can be called flat-earthers. These people believe (or disbelieve) something despite the evidence. |
Which cells continue the digestion and absorption of nutrients and transport these nutrients to the lymphatic and circulatory systems? | neurons | myocyte | blood cells | epithelial cells | Watch this animation (http://openstaxcollege. org/l/sintestine) that depicts the structure of the small intestine, and, in particular, the villi. Epithelial cells continue the digestion and absorption of nutrients and transport these nutrients to the lymphatic and circulatory systems. In the small intestine, the products of food digestion are absorbed by different structures in the villi. Which structure absorbs and transports fats?. |
Pressure is defined as the force per unit area on? | speed | weight | gravity | surface | Pressure is defined as the force per unit area on a surface. |
What do body cells use for energy? | mixtures | chlorophyll | solvents | sugars | A: You may eat a wide variety of carbohydrates—from sugars in fruits to starches in potatoes. However, body cells use only sugars for energy. |
What force pulls people and objects toward the center of the earth? | motion | magnetism | variation | gravity | You are already very familiar with Earth’s gravity. It constantly pulls you toward the center of the planet. It prevents you and everything else on Earth from being flung out into space as the planet spins on its axis. It also pulls objects above the surface, from meteors to skydivers, down to the ground. Gravity between Earth and the moon and between Earth and artificial satellites keeps all these objects circling around Earth. Gravity also keeps Earth moving around the sun. |
The rate of decay of carbon-14 does what over time? | decreases | becomes unstable | increases | remains stable | The rate of decay of carbon-14 is stable over time. |
What behavior includes all the ways that animals interact with each other and the environment? | instinct | adaptation | interdependence | animal behavior | Did you ever see a dog sit on command? Have you ever watched a cat trying to catch a mouse? These are just two examples of the many behaviors of animals. Animal behavior includes all the ways that animals interact with each other and the environment. Examples of common animal behaviors are pictured in Figure below . |
Food chains carry energy from what group to what group? | refiners to consumers | consumers to producers | decomposers to producers | producers to consumers | Food chains carry energy from producers (autotrophs) to consumers (heterotrophs). 99% of energy for life comes from the sun via photosynthesis. Note that only nutrients recycle. Energy must continue to flow into the system. Though this food chains "ends" with decomposers, do decomposers, in fact, digest matter from each level of the food chain? (See the Energy Transfer: Decomposers (Advanced) concept). |
What are professionals in technology are generally called ? | doctors | scientists | biomechanics | engineers | Companies that design and build roller coasters employ a range of technology professionals. Technology is the application of science to real-world problems. Professionals in technology are generally called engineers . Engineers are creative problem solvers. They use math and science to design and develop just about everything—from roller coasters to video games. |
What force occurs whenever two surfaces come into contact? | gravity | tension | vibration | friction | Even if Laura didn’t try to stop the skateboard, it would stop sooner or later. That’s because there’s also friction between the wheels and the pavement. Friction is a force that counters all kinds of motion. It occurs whenever two surfaces come into contact. |
The anatomy of primate eyes shows they tend to rely more on vision than what sense, which is dominant in many other mammals? | hearing | taste | touch | smell | Primates usually rely more on the sense of vision rather than the sense of smell, which is the dominant sense in many other mammals. The importance of vision in primates is reflected by the bony socket that surrounds and protects the primate eye. Primates have widely spaced eyes in the same plane that give them stereoscopic (3-D) vision, needed for judging distances. Some primates, including humans, have also evolved color vision. |
What are sensory cells? | specialized neurons or navigable cells | specialized epithelial or squirm cells | specialized neurons or squirm cells | specialized neurons or epithelial cells | |
What is it called when waves interact with other waves? | wave collision | combination interference | wave impact | wave interference | Waves interact not only with matter in the ways described above. Waves also interact with other waves. This is called wave interference . Wave interference may occur when two waves that are traveling in opposite directions meet. The two waves pass through each other, and this affects their amplitude. How amplitude is affected depends on the type of interference. Interference can be constructive or destructive. |
What is the ph level for pure water? | pH of 0 | ph of 6.47 | ph of 3.17 | ph of 7 | The extremely low hydronium ion concentration of pure water gives pure water a neutral pH of 7. Acids have a pH lower than 7, and bases have a pH higher than 7. |
What is vital for nervous system functions that include muscle stimulation, memory formation, and learning? | glycogen | thiamine | glutamate | acetylcholine | |
The benthic zone is found at the bottom of all of what type of biomes? | space | well | desert | aquatic | |
The hydroxyl radical is highly reactive because it has what? | paired electron | unpaired neutron | paired proton | unpaired electron | Because the hydroxyl radical has an unpaired electron, it is highly reactive. (This is true of any substance with unpaired electrons, known as a free radical. ) This hydroxyl radical can react with all kinds of biological molecules (DNA, proteins, enzymes, and so on), causing damage to the molecules and disrupting physiological processes. Examples of direct and indirect damage are shown in Figure 21.32. |
Gametes swim with the aid of what structure to the female gametangium, and fertilization ensues? | nucleus | oocyte | acrosome | flagella | gametes swim with the aid of their flagella to the female gametangium (the archegonium), and fertilization ensues. The zygote grows into a small sporophyte still attached to the parent gametophyte. It will give rise, by meiosis, to the next generation of spores. Liverwort plants can also reproduce asexually, by the breaking of branches or the spreading of leaf fragments called gemmae. In this latter type of reproduction, the gemmae—small, intact, complete pieces of plant that are produced in a cup on the surface of the thallus (shown in Figure 25.11)—are splashed out of the cup by raindrops. The gemmae then land nearby and develop into gametophytes. |
A phospholipid is a bond between the glycerol component of a lipid and what else? | oxygen molecule | chlorine molecule | elemental molecule | phosphorous molecule | Phospholipids As its name suggests, a phospholipid is a bond between the glycerol component of a lipid and a phosphorous molecule. In fact, phospholipids are similar in structure to triglycerides. However, instead of having three fatty acids, a phospholipid is generated from a diglyceride, a glycerol with just two fatty acid chains (Figure 2.23). The third binding site on the glycerol is taken up by the phosphate group, which in turn is attached to a polar “head” region of the molecule. Recall that triglycerides are nonpolar and hydrophobic. This still holds for the fatty acid portion of a phospholipid compound. However, the head of a phospholipid contains charges on the phosphate groups, as well as on the nitrogen atom. These charges make the phospholipid head hydrophilic. Therefore, phospholipids are said to have hydrophobic tails, containing the neutral fatty acids, and hydrophilic heads, containing the charged phosphate groups and nitrogen atom. |
What connects the fetus to the placenta? | amniotic sac | womb | fallopian tube | umbilical cord | The placenta allows nutrients and wastes to be exchanged between the mother and fetus. The fetus is connected to the placenta through the umbilical cord. |
In desert cactus, thorns that protect the water held in a large, barrel-shaped stem are an example of what? | species | feature | characteristic | adaptation | The saguaro cactus pictured in Figure below has adapted in all three ways. When it was still a very small plant, just a few inches high, its shallow roots already reached out as much as 2 meters (7 feet) from the base of the stem. By now, its root system is much more widespread. It allows the cactus to gather as much moisture as possible from rare rainfalls. The saguaro doesn’t have any leaves to lose water by transpiration. It also has a large, barrel-shaped stem that can store a lot of water. Thorns protect the stem from thirsty animals that might try to get at the water inside. |
What are the most common dietary lipids? | monoglycerides | phospholipids | diglycerides | triglycerides | Lipid Digestion A healthy diet limits lipid intake to 35 percent of total calorie intake. The most common dietary lipids are triglycerides, which are made up of a glycerol molecule bound to three fatty acid chains. Small amounts of dietary cholesterol and phospholipids are also consumed. The three lipases responsible for lipid digestion are lingual lipase, gastric lipase, and pancreatic lipase. However, because the pancreas is the only consequential source of lipase, virtually all lipid digestion occurs in the small intestine. Pancreatic lipase breaks down each triglyceride into two free fatty acids and a monoglyceride. The fatty acids include both short-chain (less than 10 to 12 carbons) and long-chain fatty acids. |
What process is the opposite of fusion and releases energy only when heavy nuclei are split? | diffusion | activation | osmosis | fission | Fission is the opposite of fusion and releases energy only when heavy nuclei are split. As noted in Fusion, energy is released if the products of a nuclear reaction have a greater binding energy per nucleon ( BE / A ) than the parent nuclei. Figure 32.25. |
Visible light is the narrow segment of what, to which the normal human eye responds? | phenomena spectrum | molecular spectrum | radio spectrum | electromagnetic spectrum | Visible Light Visible light is the narrow segment of the electromagnetic spectrum to which the normal human eye responds. Visible light is produced by vibrations and rotations of atoms and molecules, as well as by electronic transitions within atoms and molecules. The receivers or detectors of light largely utilize electronic transitions. We say the atoms and molecules are excited when they absorb and relax when they emit through electronic transitions. Figure 24.16 shows this part of the spectrum, together with the colors associated with particular pure wavelengths. We usually refer to visible light as having wavelengths of between 400 nm and 750 nm. (The retina of the eye actually responds to the lowest ultraviolet frequencies, but these do not normally reach the retina because they are absorbed by the cornea and lens of the eye. ) Red light has the lowest frequencies and longest wavelengths, while violet has the highest frequencies and shortest wavelengths. Blackbody radiation from the Sun peaks in the visible part of the spectrum but is more intense in the red than in the violet, making the Sun yellowish in appearance. |
Bromine is much less abundant than fluorine or chlorine, but it is easily recovered from seawater, which contains about 65 mg of br− per what? | gallon | pound | foot | liter | electrolysis2NaOH ( aq ) + Cl2 ( g ) + H 2 ( g ) Bromine is much less abundant than fluorine or chlorine, but it is easily recovered from seawater, which contains about 65 mg of Br− per liter. Salt lakes and underground brines are even richer sources; for example, the Dead Sea contains 4 g of Br− per liter. Iodine is the least abundant of the nonradioactive halogens, and it is a relatively rare element. Because of its low electronegativity, iodine tends to occur in nature in an oxidized form. Hence most commercially important deposits of iodine, such as those in the Chilean desert, are iodate salts such as Ca(IO3)2. The production of iodine from such deposits therefore requires reduction rather than oxidation. The process is typically carried out in two steps: reduction of iodate to iodide with sodium hydrogen sulfite, followed by reaction of iodide with additional iodate: Equation 22.41. |
Karyotyping shows whether what structures, which contain genetic information, are normal in number and appearance? | nucleoids | neutrons | ribosomes | chromosomes | |
Real gases deviate from ideal form at high pressure and what other thermodynamic condition? | high temperatures | high winds | low pressure | low temperatures | Real gases deviate from ideal gases at high pressures and at low temperatures. |
Organic substances, including proteins, carbohydrates, and oils, contain what element? | iron | oxygen | acid | carbon | A mineral is an inorganic substance. It was not made by living organisms. Organic substances contain carbon. Some types of organic substances are proteins, carbohydrates, and oils. Everything else is inorganic. In a few cases, living organisms make inorganic materials. The calcium carbonate shells made by marine animals are inorganic. |
What term describes anything that occupies space and has mass, and is generally divided into three states? | galaxy | stuff | lquid | matter | Matter is anything that occupies space and has mass. The three states of matter are solid, liquid, and gas. A physical change involves the conversion of a substance from one state of matter to another, without changing its chemical composition. Most matter consists of mixtures of pure substances, which can behomogeneous (uniform in composition) or heterogeneous (different regions possess different compositions and properties). Pure substances can be either chemical compounds or elements. Compounds can be broken down into elements by chemical reactions, but elements cannot be separated into simpler substances by chemical means. The properties of substances can be classified as either physical or chemical. Scientists can observe physical properties without changing the composition of the substance, whereas chemical propertiesdescribe the tendency of a substance to undergo chemical changes (chemical reactions) that change its chemical composition. Physical properties can be intensive or extensive. Intensive properties are the same for all samples; do not depend on sample size; and include, for example, color, physical state, and melting and boiling points. Extensive properties depend on the amount of material and include mass and volume. The ratio of two extensive properties, mass and volume, is an important intensive property called density. |
When light strikes the rods and cones, they hyperpolarize, shutting off their release of what? | dopamine | enzyme | vitreous fluid | glutamate | |
The heart contracts rhythmically to pump what to the lungs and the rest of the body? | Chyle | Bile | Cerumen | blood | The heart contracts rhythmically to pump blood to the lungs and the rest of the body. Specialized cardiac muscle cells trigger the contractions. |
What do light emitters do to what you see? | block frequencies | divide frequencies | subtract frequencies | add frequencies | Discussions of colors can sometimes become confusing because of the difference between light emitters and light absorbers. Light absorbers, such as dyes and pigments, absorb frequencies from those that you see, while light emitters add frequencies to what you see. If I were to shine red light, green light, and blue light into your eye all at the same time, you would likely see some variation of white. If I were to mix red paint, green paint, and blue paint together, you would likely see black or some very dark color. |
A turbine using tides in the ocean can create what type of energy? | kinetic | conversion | diffused | electricity | Tides in the ocean can also turn a turbine to create electricity. This energy can then be stored until needed ( Figure below ). |
The atomic number is the same as the number of what in an atom? | electrons | neutrons | ions | protons | The number of protons in an atom is called its atomic number. This is also unique for each element. |
What is the closed circulatory system of humans and other vertebrates called? | respiratory system | digestive system | reproductive system | cardiovascular system | |
"red-shift" refers to a shift toward red in the spectrum from what celestial bodies? | comets | galaxies | planets | stars | The spectrum from stars is shifted toward the red; this is known as red-shift. Red-shift of galaxies is evidence that the Universe is expanding. |
What is the name for substances with a ph above 7? | protein | acid | nutrient | bases | Bases have a lower concentration of hydronium ions than pure water, and a pH higher than 7. |
The subducting oceanic plate does what as it reenters the mantle? | freezes | evaporates | disappers | melts | As you would expect, where plates collide there are lots of intense earthquakes and volcanic eruptions. The subducting oceanic plate melts as it reenters the mantle. The magma rises and erupts. This creates a volcanic mountain range near the coast of the continent. This range is called a continental arc . The Andes Mountains, along the western edge of South America, are a volcanic arc ( Figure below ). |
Which stage of development is a period during which apoptosis is widespread and plays a crucial role? | infancy | puberty | transgenic | embryonic | |
What orifice in the body is particularly helpful in both digestion and respiration? | anus | nostril | nose | mouth | |
What subphylum, which includes crabs and crayfish, represents the dominant aquatic arthropods? | invertebrates | arachnids | sponges | crustaceans | Crustaceans, such as shrimp, lobsters, crabs, and crayfish, are the dominant aquatic arthropods. A few crustaceans are [3] terrestrial species like the pill bugs or sow bugs. The number of described crustacean species stands at about 47,000. Although the basic body plan in crustaceans is similar to the Hexapoda—head, thorax, and abdomen—the head and thorax may be fused in some species to form a cephalothorax, which is covered by a plate called the carapace (Figure 15.22). The exoskeleton of many species is also infused with calcium carbonate, which makes it even stronger than in other arthropods. Crustaceans have an open circulatory system in which blood is pumped into the hemocoel by the dorsal heart. Most crustaceans typically have separate sexes, but some, like barnacles, may be hermaphroditic. Serial hermaphroditism, in which the gonad can switch from producing sperm to ova, is also found in some crustacean species. Larval stages are seen in the early development of many crustaceans. Most crustaceans are carnivorous, but detritivores and filter feeders are also common. |
What do neurons pass to the next neuron? | receptors | contaminants | blood | neurotransmitters | Did you ever watch a relay race? After the first runner races, he or she passes the baton to the next runner, who takes over. Neurons are a little like relay runners. Instead of a baton, they pass neurotransmitters to the next neuron. Examples of neurotransmitters are chemicals such as serotonin, dopamine, and adrenaline. |
What determines which type of precipitation falls in the atmosphere? | time of day | air density | moon phase | air temperature | Why does it snow instead of rain? Air temperature determines which type of precipitation falls. Rain falls if the air temperature is above freezing (0° C or 32° F). Frozen precipitation falls if the air or ground is below freezing. Frozen precipitation may fall as snow , sleet , or freezing rain . Below, you can see how the different types form ( Figure below ). |
The main functions of what complex carbohydrates are to store energy and form structural tissues? | monosaccharides | polypeptides | oligosaccharides | polysaccharides | The main functions of polysaccharides are to store energy and form structural tissues. Examples of several other polysaccharides and their roles are listed in the Table below . These complex carbohydrates play important roles in living organisms. |
High consumption of saturated fats is linked to an increased risk of what disease? | diabetes | pulmonary edema | high blood pressure | cardiovascular disease | Unsaturated fat is generally considered to be healthier because it contains fewer calories than an equivalent amount of saturated fat. Additionally, high consumption of saturated fats is linked to an increased risk of cardiovascular disease. Some examples of foods with high concentrations of saturated fats include butter, cheese, lard, and some fatty meats. Foods with higher concentrations of unsaturated fats include nuts, avocado, and vegetable oils such as canola oil and olive oil. The Figure below shows the percentages of fat types in some common foods. |
What does hair get its color from? | fluorescent pigments | elasticity pigments | stimulating pigments | melanin pigments | 5.2 Accessory Structures of the Skin Accessory structures of the skin include hair, nails, sweat glands, and sebaceous glands. Hair is made of dead keratinized cells, and gets its color from melanin pigments. Nails, also made of dead keratinized cells, protect the extremities of our. |
What type of animal in the sea spend most of their lives as medusae? | whales | fish | sharks | jellyfish | Jellyfish spend most of their lives as medusae. They live virtually everywhere in the ocean. They prey on zooplankton, other invertebrates, and the eggs and larvae of fish. |
Desert plants have evolved processes to conserve water and deal with harsh conditions. a more efficient use of co2 allows plants to adapt to living with what? | more sunlight | less competition | more water | less water | perpendicular to the surface at the point where the ray strikes the surface. |
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