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What system consists of organs that break down food and absorb nutrients such as glucose? | skeletal system | cardiovascular system | physical system | digestive system | The digestive system consists of organs that break down food and absorb nutrients such as glucose. Organs of the digestive system are shown in Figure below . Most of the organs make up the gastrointestinal tract . The rest of the organs are called accessory organs . |
What is the transition from solid to vapor is called? | ionization | vaporization | deposition | sublimation | Sublimation is the transition from solid to vapor phase. You may have noticed that snow can disappear into thin air without a trace of liquid water, or the disappearance of ice cubes in a freezer. The reverse is also true: Frost can form on very cold windows without going through the liquid stage. A popular effect is the making of “smoke” from dry ice, which is solid carbon dioxide. Sublimation occurs because the equilibrium vapor pressure of solids is not zero. Certain air fresheners use the sublimation of a solid to inject a perfume into the room. Moth balls are a slightly toxic example of a phenol (an organic compound) that sublimates, while some solids, such as osmium tetroxide, are so toxic that they must be kept in sealed containers to prevent human exposure to their sublimation-produced vapors. |
In contrast with cnidarians, nematodes show a tubular morphology and circular cross-section. these animals are pseudocoelomates and show the presence of a complete digestive system with a distinct mouth and this? | stomach | mucus | hairs | anus | present in all habitats with a large number of individuals of each species present in each. The free-living nematode, Caenorhabditis elegans has been extensively used as a model system in laboratories all over the world. Morphology In contrast with cnidarians, nematodes show a tubular morphology and circular cross-section. These animals are pseudocoelomates and show the presence of a complete digestive system with a distinct mouth and anus. This is in contrast with the cnidarians, where only one opening is present (an incomplete digestive system). The cuticle of Nematodes is rich in collagen and a carbohydrate-protein polymer called chitin, and forms an external “skeleton” outside the epidermis. The cuticle also lines many of the organs internally, including the pharynx and rectum. The epidermis can be either a single layer of cells or a syncytium, which is a multinucleated cell formed from the fusion of uninucleated cells. The overall morphology of these worms is cylindrical, as seen in Figure 28.31. The head is radially symmetrical. A mouth opening is present at the anterior end with three or six lips as well as teeth in some species in the form of cuticle extensions. Some nematodes may present other external modifications like rings, head shields, or warts. Rings, however, do not reflect true internal body segmentation. The mouth leads to a muscular pharynx and intestine, which leads to a rectum and anal opening at the posterior end. The muscles of nematodes differ from those of most animals: They have a longitudinal layer only, which accounts for the whip-like motion of their movement. |
The amount of heat required to raise a single mass unit of a substance by a single temperature unit is known as what? | solitary heat | temperature variation | specific gravity | specific heat | When heat flows into an object, its thermal energy increases and so does its temperature. The amount of temperature increase depends on three things: 1) how much heat was added, 2) the size of the object, and 3) the material of which the object is made. When you add the same amount of heat to the same mass of different substances, the amount of temperature increase is different. Each substance has a specific heat, which is the amount of heat necessary to raise one mass unit of that substance by one temperature unit. |
What is the most important source of electromagnetic radiation on earth? | the oceans | the moon | volcanos | the sun | The most important source of electromagnetic radiation on Earth is the sun. Electromagnetic waves travel from the sun to Earth across space and provide virtually all the energy that supports life on our planet. Many other sources of electromagnetic waves that people use depend on technology. Radio waves, microwaves, and X rays are examples. We use these electromagnetic waves for communications, cooking, medicine, and many other purposes. You’ll learn about all these types of electromagnetic waves in this chapter’s lesson on "The Electromagnetic Spectrum. ". |
What kind of drugs are formulated to help deal with hiv and herpes as well as influenza and two types of hepatitis? | herbal remedies | antibacterial drugs | steroid drugs | antiviral drugs | Like antibiotics, specific antivirals are used for specific viruses. They are relatively harmless to the host, and therefore can be used to treat infections. Most of the antiviral drugs now available are designed to help deal with HIV and herpes viruses. Antivirals are also available for the influenza viruses and the Hepatitis B and C viruses, which can cause liver cancer. |
Trees, which can be planted and harvested, are an example of what type of resource? | geothermal | electric | fossil | renewable | Trees are renewable resources. Trees can be planted, grown up, and harvested for timber. Forests are a different thing, however. A forest is a mature ecosystem. It has trees of different sizes and ages, many other plants, and lots of animals. A forest is a renewable resource but it takes much more time to grow a forest than to grow a stand of trees. |
After a supernova, what part of a star remains? | superficial | large | outer | core | After a supernova explosion, the star's core is left over. This material is extremely dense. What happens next depends on the core's mass. The core might be less than about four times the mass of the sun. In this case, the star will become a neutron star. A neutron star ( Figure below ) is made almost entirely of neutrons. A neutron star has more mass than the sun; yet, it is only a few kilometers in diameter. |
What is essential for population of all species to expand greatly? | liquid resources | foliage resources | chemical resources | abundant resources | |
What is usually the most visible part of the flower? | roots | cells | seeds | petals | Petals are usually the most visible parts of a flower. They may be large and showy and are often brightly colored. Leaf-like green sepals protect the flower while it is still a bud. |
What do ionic bonds form between? | metals and organisms | metals and carbonates | metals and freshwaters | metals and nonmetals | Ionic bonds form only between metals and nonmetals. That’s because metals “want” to give up electrons, and nonmetals “want” to gain electrons. |
The interaction between atomic orbitals is greatest when they have the same what? | fuel | temperature | mass | energy | The number of molecular orbitals produced is the same as the number of atomic orbitals used to create them (the law of conservation of orbitals). As the overlap between two atomic orbitals increases, the difference in energy between the resulting bonding and antibonding molecular orbitals increases. When two atomic orbitals combine to form a pair of molecular orbitals, the bonding molecular orbital is stabilized about as much as the antibonding molecular orbital is destabilized. The interaction between atomic orbitals is greatest when they have the same energy. |
What occurs when competing species evolve different adaptations? | Rate Adaption | evolution | urbanization | specialization | Instead of extinction, interspecific competition may lead to greater specialization. Specialization occurs when competing species evolve different adaptations. For example, they may evolve adaptations that allow them to use different food sources. Figure below describes an example. |
Haversian canals contain blood vessels and what else? | collagen fibers | muscle fibers | synovial fluid | nerve fibers | Compact bone tissue is made of cylindrical osteons that are aligned such that they travel the length of the bone. Haversian canals contain blood vessels only. Haversian canals contain blood vessels and nerve fibers. Spongy tissue is found on the interior of the bone, and compact bone tissue is found on the exterior. Figure 38.37 Which of the following statements about muscle contraction is true?. |
What type of telescopes collect and focus radio waves from distant objects? | space telescopes | reflecting telescopes | refracting telescopes | radio telescopes | Radio telescopes collect and focus radio waves from distant objects. |
Cells have multiple repair mechanisms to fix mutations in what? | RNA | amino acid chains | organ systems | dna | Many other mutations have no effect on the organism because they are repaired before protein synthesis occurs. Cells have multiple repair mechanisms to fix mutations in DNA. One way DNA can be repaired is illustrated in Figure below . If a cell’s DNA is permanently damaged and cannot be repaired, the cell is likely to be prevented from dividing. |
What are different versions of a gene known as? | genomes | modes | ion | alleles | The gene for a characteristic may have different versions. These different versions of a gene are known as alleles. |
All chemical reactions involve both reactants and what else? | energy | consumers | catalysts | products | All chemical reactions involve both reactants and products. Reactants are substances that start a chemical reaction, and products are substances that are produced in the reaction. |
Potassium hydroxide in soap is an example of what? | acid | enzyme | catalyst | base | Bases are used for a variety of purposes. For example, soaps contain bases such as potassium hydroxide (KOH). Other uses of bases can be seen in the Figure below . |
What is the process by which organisms give rise to offspring? | photosynthesis | differentiation | evolution | reproduction | Reproduction is the process by which organisms give rise to offspring. It is one of the defining characteristics of living things. There are two basic types of reproduction: asexual reproduction and sexual reproduction. |
Photosynthesis is an endothermic reaction that gets its energy from what? | air | wind | electricity | light | One of the most important series of endothermic reactions is photosynthesis. The energy needed for photosynthesis comes from light. |
Paramecium possess tiny hair-like cilia that help them do what? | breed | fight | look | move | Some protists, like these Paramecium , act much like animals. Notice the tiny hair-like cilia that help them move. The food vacuoles, where they digest their prey, are colored in orange. |
What is a complex machine that burns fuel to produce thermal energy and then uses the thermal energy to do work? | battery | vapor engine | convection oven | combustion engine | A combustion engine is a complex machine that burns fuel to produce thermal energy and then uses the thermal energy to do work. Combustion engines may by external or internal combustion engines, depending on where the fuel is burned. |
In both eukaryotes and prokaryotes, ribosomes are the non-membrane bound organelles where what main product of the cell is made? | sugars | lipids | protons | proteins | In both eukaryotes and prokaryotes, ribosomes are the non-membrane bound organelles where proteins are made. Ribosomes are like the machines in the factory that produce the factory's main product. Proteins are the main product of the cell. |
What is it called when ice changes to liquid water? | condensing | vaporizing | boiling | melting | |
Biological features from a common evolutionary origin are known as what? | analogous | monologous | heterologous | homologous | Classification of Living Things be that different. Biological features from a common evolutionary origin are known as homologous. • Development • Biochemistry: Biochemical analysis of animals similar in appearance have yielded surprising results. For example, although guinea pigs were once considered to be rodents, like mice, biochemistry led them to be in their taxon of their own. |
Salts that are neither acidic nor basic do not affect what property of the solution when dissolved in water? | density | homeostasis | saturation | ph | The simplest situation is a salt formed by combining a strong acid and a strong base. These salts are neither acidic nor basic, so they do not affect the pH of the solution when dissolved in water. For example, the ionic compound NaNO 3 could be prepared by combining the strong acid HNO 3 and the strong base NaOH. If we were to dissolve NaNO 3 in water, it would dissociate into Na + and NO 3 - ions. Neither ion is a strong enough acid or base to cause any noticeable proton transfers, so the pH of the pure water is not altered. |
What protects the pollen of seed plants and spores of seedless plants? | chlorophyll | cystosol | cocklebur | sporopollenin | The spores of seedless plants and the pollen of seed plants are surrounded by thick cell walls containing a tough polymer known as sporopollenin. This substance is characterized by long chains of organic molecules related to fatty acids and carotenoids, and gives most pollen its yellow color. Sporopollenin is unusually resistant to chemical and biological degradation. Its toughness explains the existence of well-preserved fossils of pollen. Sporopollenin was once thought to be an innovation of land plants; however, the green algae Coleochaetes is now known to form spores that contain sporopollenin. Protection of the embryo is a major requirement for land plants. The vulnerable embryo must be sheltered from desiccation and other environmental hazards. In both seedless and seed plants, the female gametophyte provides nutrition, and in seed plants, the embryo is also protected as it develops into the new generation of sporophyte. |
Cells that have a nucleus and other organelles which are membrane-bound are generally called what kinds of cells? | Erythrocyte | Monocyte | Megakaryocyte | eukaryotic | Eukaryotic cells have a nucleus and other membrane-bound organelles. This allows these cells to have complex functions. |
What is first stage of cellular respiration? | metabolism | electrolysis | hydrolisis | glycolsis | The first stage of cellular respiration is glycolysis . It does not require oxygen, and it does not take place in the mitochondrion - it takes place in the cytosol of the cytoplasm. |
What are groups of stars called that are smaller than a galaxy? | constellations | Milky Way | nebuli | star clusters | Star clusters are groups of stars smaller than a galaxy. There are two main types, open clusters and globular clusters. Open clusters are groups of up to a few thousand stars held together by gravity. The Jewel Box, shown in Figure below , is an open cluster. Open clusters tend to be blue in color, and often contain glowing gas and dust. The stars in an open cluster are young stars that all formed from the same nebula. |
Expansion of a gas into a vacuum is irreversible because the external pressure is measurably less than the internal pressure of the gas, and no states of what exist? | composition | balance | liquid | equilibrium | can continue indefinitely. In contrast, the expansion of a gas into a vacuum (Pext = 0) is irreversible because the external pressure is measurably less than the internal pressure of the gas. No equilibrium states exist, and the gas expands irreversibly. When gas escapes from a microscopic hole in a balloon into a vacuum, for example, the process is irreversible; the direction of airflow cannot change. Because work done during the expansion of a gas depends on the opposing external pressure (w = PextΔV), work done in a reversible process is always equal to or greater than work done in a corresponding irreversible process: wrev ≥ wirrev. Whether a process is reversible or irreversible, ΔE = q + w. Because E is a state function, the magnitude of ΔE does not depend on reversibility and is independent of the path taken. So Equation 18.14. |
One important phenomenon related to the relative strength of cohesive and adhesive forces is capillary action—the tendency of a fluid to be raised or suppressed in a narrow tube, or called this? | pressure tube | melting tube | cohesive tube | capillary tube | One important phenomenon related to the relative strength of cohesive and adhesive forces is capillary action—the tendency of a fluid to be raised or suppressed in a narrow tube, or capillary tube. This action causes blood to be drawn into a small-diameter tube when the tube touches a drop. Capillary Action The tendency of a fluid to be raised or suppressed in a narrow tube, or capillary tube, is called capillary action. If a capillary tube is placed vertically into a liquid, as shown in Figure 11.34, capillary action will raise or suppress the liquid inside the tube depending on the combination of substances. The actual effect depends on the relative strength of the cohesive and adhesive forces and, thus, the contact angle θ given in the table. If θ is less than 90º , then the fluid will be raised; if θ is greater than 90º , it will be suppressed. Mercury, for example, has a very large surface tension and a large contact angle with glass. When placed in a tube, the surface of a column of mercury curves downward, somewhat like a drop. The curved surface of a fluid in a tube is called a meniscus. The tendency of surface tension is always to reduce the surface area. Surface tension thus flattens the curved liquid surface in a capillary tube. This results in a downward force in mercury and an upward force in water, as seen in Figure 11.34. |
What happens to air density and pressure when gas molecules are warm? | they are greater | they are unchanged | they are equal | they are lower | When gas molecules are warm, they move vigorously. They take up more space. Air density and air pressure are lower. |
What kind of reproduction generates most of the genetic variation that makes evolutionary adaptation possible? | synthetic reproduction | cloning | asexual reproduction | sexual reproduction | |
Can nematodes be a parasite of plants, animals, or both? | plants | neither | animals | both | Nematodes can be parasites of plants and animals. |
What kind of weather can you expect if a center of low pressure is moving your way? | sunny | rain | rough | stormy | Weather is very difficult to predict. That’s because it’s very complex and many factors are involved. Slight changes in even one factor can cause a big change in the weather. Still, certain “rules of thumb” generally apply. These “rules” help meteorologists forecast the weather. For example, low pressure is likely to bring stormy weather. So if a center of low pressure is moving your way, you can expect a storm. |
What is a thin membrane stretched tight across the end of the ear canal that vibrates when sound waves strike it? | auricle | earlobe | cerebrum | eardrum | The eardrum is like the head of a drum. It’s a thin membrane stretched tight across the end of the ear canal. The eardrum vibrates when sound waves strike it, and it sends the vibrations on to the middle ear. |
Icy objects that have very elliptical orbits around the sun are called? | craters | meteors | asteroids | comets | Comets are icy objects that have very elliptical orbits around the Sun. |
What geologic era is also known as the age of mammals? | cretaceous period | mesozoic era | paleozoic era | cenozoic era | The Cenozoic Era literally means the era of “modern life. ” It is also called the age of mammals. Mammals took advantage of the extinction of the dinosaurs. They flourished and soon became the dominant animals on Earth. You can learn more about the evolution of mammals during the Cenozoic at the link below. The Cenozoic began 65 million years ago and continues to the present. It may be divided into the two periods described in Figure below . http://www. youtube. com/watch?v=H0uTGkCWXwQ. |
Radioactive atoms, nuclear explosions, and stars produce what types of rays. | beta | plasma | neutron | gamma | Sources of gamma rays include radioactive atoms, nuclear explosions, and stars. Gamma rays from space are absorbed by Earth’s atmosphere. |
The similarities and differences between the genomes confirm patterns of what? | variation | phylum | fossils | evolution | The similarities and differences between the genomes confirm patterns of evolution. |
What are the two components of all solutions? | concentration and solvent | sodium and solvent | solute and cytosol | solute and solvent | All solutions have two parts: the solute and the solvent. The solute is the substance that dissolves, and the solvent is the substance that dissolves the solute. Particles of solvent pull apart particles of solute, and the solute particles spread throughout the solvent. Salt water, such as the ocean water in the Figure below , is an example of a solution. In a saltwater solution, salt is the solute and water is the solvent. |
On how many of the continents do birds live and breed? | eight | three | four | seven | Birds live and breed in most terrestrial habitats on all seven continents. They occupy a wide range of ecological positions. Raptors are carnivores; aquatic birds eat fish or water plants; and perching birds may eat insects, fruit, honey, or nectar. Some birds are pollinators that co-evolved with plants. Human actions have caused the extinction of hundreds of species of birds, and some 1,200 species are threatened with extinction today. |
The hydrogen is oxidized because it undergoes a partial loss of what? | ions | density | protons | electrons | In the course of this reaction, electrons are shifted away from each hydrogen atom and towards the oxygen atom. The hydrogen is oxidized because it undergoes a partial loss of electrons. Even though the loss is not complete enough to form ions, the hydrogen atoms in water have less electron density near them than they did in the H 2 molecule. The oxygen is reduced because it undergoes a partial gain of electrons. The oxygen atom in water has greater electron density near it than they did in the O 2 molecule. |
What is land with permafrost, no trees, and small hardy plants? | desert | subtropics | taiga | tundra | Tundra is land with permafrost, no trees, and small hardy plants. |
Viruses replicate only in where? | weak cells | traitor cells | compromised cells | host cells | 19.2 Viruses replicate only in host cells. |
Matter undergoing chemical reactions and physical changes can release or absorb heat. a change that releases heat is called what? | biochemical process | magnetic process | oxidized process | exothermic process | Matter undergoing chemical reactions and physical changes can release or absorb heat. A change that releases heat is called an exothermic process. For example, the combustion reaction that occurs when using an oxyacetylene torch is an exothermic process—this process also releases energy in the form of light as evidenced by the torch’s flame (Figure 5.7). A reaction or change that absorbs heat is an endothermic process. A cold pack used to treat muscle strains provides an example of an endothermic process. When the substances in the cold pack (water and a salt like ammonium nitrate) are brought together, the resulting process absorbs heat, leading to the sensation of cold. |
What hormone secreted by the pineal gland controls sleep-wake cycles and several other processes? | estrogen | testosterone | t3 | melatonin | The pineal gland is a tiny gland located at the base of the brain. It secretes the hormone melatonin . This hormone controls sleep-wake cycles and several other processes. |
What is defined as the ability to do work? | momentum | fuel | heating | energy | Energy is the ability to do work. Fuel stores energy and can be released to do work. Heat is given off when fuel is burned. |
What two types of tissue compose most of the non-pregnant and non-lactating female breast? | scar and collagenous | intestine and collagenous | silicone and collagenous | adipose and collagenous | Structure of the Lactating Breast Mammary glands are modified sweat glands. The non-pregnant and non-lactating female breast is composed primarily of adipose and collagenous tissue, with mammary glands making up a very minor proportion of breast volume. The mammary gland is composed of milk-transporting lactiferous ducts, which expand and branch extensively during pregnancy in response to estrogen, growth hormone, cortisol, and prolactin. Moreover, in response to progesterone, clusters of breast alveoli bud from the ducts and expand outward toward the chest wall. Breast alveoli are balloon-like structures lined with milk-secreting cuboidal cells, or lactocytes, that are surrounded by a net of contractile myoepithelial cells. Milk is secreted from the lactocytes, fills the alveoli, and is squeezed into the ducts. Clusters of alveoli that drain to a common duct are called lobules; the lactating female has 12–20 lobules organized radially around the nipple. Milk drains from lactiferous ducts into lactiferous sinuses that meet at 4 to 18 perforations in the nipple, called nipple pores. The small bumps of the areola (the darkened skin around the nipple) are called Montgomery glands. They secrete oil to cleanse the nipple opening and prevent chapping and cracking of the nipple during breastfeeding. |
Control of the body can be somatic or autonomic, offering one way to divide what organ system by function? | central system | cardiovascular system | circulatory system | nervous system | Functional Divisions of the Nervous System The nervous system can also be divided on the basis of its functions, but anatomical divisions and functional divisions are different. The CNS and the PNS both contribute to the same functions, but those functions can be attributed to different regions of the brain (such as the cerebral cortex or the hypothalamus) or to different ganglia in the periphery. The problem with trying to fit functional differences into anatomical divisions is that sometimes the same structure can be part of several functions. For example, the optic nerve carries signals from the retina that are either used for the conscious perception of visual stimuli, which takes place in the cerebral cortex, or for the reflexive responses of smooth muscle tissue that are processed through the hypothalamus. There are two ways to consider how the nervous system is divided functionally. First, the basic functions of the nervous system are sensation, integration, and response. Secondly, control of the body can be somatic or autonomic—divisions that are largely defined by the structures that are involved in the response. There is also a region of the peripheral nervous system that is called the enteric nervous system that is responsible for a specific set of the functions within the realm of autonomic control related to gastrointestinal functions. |
What is the female reproductive structure of a flower? | the flower | the stamen | the seed | the pistil | The pistil is the female reproductive structure of a flower. It consists of a stigma, style , and ovary . The stigma is raised and sticky to help it catch pollen. The style supports the stigma and connects it to the ovary, which contains the egg. Petals attract pollinators to the flower. Petals are often brightly colored so pollinators will notice them. |
Cysteine is a type of what fundamental building block of protein? | salts acid | atoms acid | proteins acid | amino acid | Food and Drink App: Amino Acids—Essential and Otherwise The text mentioned cysteine, an amino acid. Amino acids are the fundamental building blocks of proteins, a major biological component. Proteins are a necessary part of the diet; meat, eggs, and certain vegetables such as beans and soy are good sources of protein and amino acids. All life on Earth—from the lowliest single-celled organism to humans to blue whales—relies on proteins for life, so all life on Earth is dependent on amino acids. The human body contains 20 different amino acids (curiously, other organisms may have a different number of amino acids). However, not all of them must be obtained from the diet. The body can synthesize 12 amino acids. The other 8 mustbe obtained from the diet. These 8 amino acids are called the essential amino acids. Daily requirements range from 4 mg per kilogram of body weight for tryptophan to 40 mg per kilogram of body weight for leucine. Infants and children need a greater mass per kg of body weight to support their growing bodies; also, the number of amino acids that are considered essential for infants and children is greater than for adults due to the greater protein synthesis associated with growth. Because of the existence of essential amino acids, a diet that is properly balanced in protein is necessary. Rice and beans, a very popular food dish Saylor URL: http://www. saylor. org/books. |
The leaves of what plant genus are the source of the compound ephedrine, which is used in medicine as a potent decongestant and is similar to amphetamines? | additive | Stimulant | dietary | ephedra | years. The genus Ephedra is represented in North America in dry areas of the southwestern United States and Mexico (Figure 14.23). Ephedra’s small, scale-like leaves are the source of the compound ephedrine, which is used in medicine as a potent decongestant. Because ephedrine is similar to amphetamines, both in chemical structure and neurological effects, its use is restricted to prescription drugs. Like angiosperms, but unlike other gymnosperms, all gnetophytes possess vessel elements in their xylem. |
The simplest organic compounds are known as what? | nucleotides | amino acids | carbohydrates | hydrocarbons | Opening Essay Hydrocarbons are the simplest organic compounds, but they have interesting physiological effects. These effects depend on the size of the hydrocarbon molecules and where on or in the body they are applied. Alkanes of low molar mass—those with from 1 to approximately 10 or so carbon atoms—are gases or light liquids that act as anesthetics. Inhaling (“sniffing”) these hydrocarbons in gasoline or aerosol propellants for their intoxicating effect is a major health problem that can lead to liver, kidney, or brain damage or to immediate death by asphyxiation by excluding oxygen. Swallowed, liquid alkanes do little harm while in the stomach. In the lungs, however, they cause “chemical” pneumonia by dissolving fatlike molecules from cell membranes in the tiny air sacs (alveoli). The lungs become unable to expel fluids, just as in pneumonia caused by bacteria or viruses. People who swallow gasoline or other liquid alkane mixtures should not be made to vomit, as this would increase the chance of getting alkanes into the lungs. (There is no home-treatment antidote for gasoline poisoning; call a poison control center. ) Liquid alkanes with approximately 5–16 carbon atoms per molecule wash away natural skin oils and cause drying and chapping of the skin, while heavier liquid alkanes (those with approximately 17 or more carbon atoms per molecule) act as emollients (skin softeners). Such alkane mixtures as mineral oil and petroleum jelly can be applied as a protective film. Water and aqueous solutions such as urine will not dissolve such a film, which explains why petroleum jelly protects a baby’s tender skin from diaper rash. |
Who developed a classification system that divided living things into several groups that we still use today, including mammals, insects, and reptiles? | harrold | jung | darwin | aristotle | People have been concerned with classifying organisms for thousands of years. Over 2,000 years ago, the Greek philosopher Aristotle developed a classification system that divided living things into several groups that we still use today, including mammals, insects, and reptiles. |
All biochemical molecules have oxygen, carbon, and what other element? | calcium | helium | nitrogen | hydrogen | All biochemical molecules contain hydrogen and oxygen as well as carbon. They may also contain nitrogen, phosphorus, and/or sulfur. Almost all biochemical compounds are polymers. Polymers are large molecules that consist of many smaller, repeating molecules, called monomers. Glucose is a monomer of biochemical compounds called starches. In starches and all other biochemical polymers, monomers are joined together by covalent bonds, in which atoms share pairs of valence electrons. |
What is a structure that is composed of one or more types of tissues? | node | system | muscle | organ | Organ : Structure composed of one or more types of tissues. The tissues of an organ work together to perfume a specific function. Human organs include the brain, stomach, kidney, and liver. Plant organs include roots, stems, and leaves. |
If the buoyant force is greater than the force of gravity acting on a ship, what will happen to the ship? | it will explode | it will sink | it will bobble | it will float | Now look at the ship’s hull in the Figure above . Its shape causes the ship to displace much more water than the ball. In fact, the weight of the displaced water is greater than the weight of the ship. As a result, the buoyant force is greater than the force of gravity acting on the ship, so the ship floats. |
What are different types of tissues organized into functional units called? | veins | tendons | arteries | organs | |
Practitioners of what thought all matter was composed of different proportions of four basic elements, and that if you changed the proportions of these elements, you could change the substance itself? | phrenology | chemistry | biology | alchemy | Alchemy was a somewhat mystical and secretive approach to learning how to manipulate matter. Practitioners, called alchemists, thought that all matter was composed of different proportions of the four basic elements—fire, water, earth, and air—and believed that if you changed the relative proportions of these elements in a substance, you could change the substance. The long-standing attempts to “transmute” common metals into gold represented one goal of alchemy. Alchemy’s other major goal was to synthesize the philosopher’s stone, a material that could impart long life—even immortality. Alchemists used symbols to represent substances, some of which are shown in the accompanying figure. This was not done to better communicate ideas, as chemists do today, but to maintain the secrecy of alchemical knowledge, keeping others from sharing in it. |
What are atoms of the same element that differ in their numbers of neutrons called? | opposites | reactions | organisms | isotopes | The first plants were probably similar to the stoneworts in Figure below . Stoneworts are green algae. Like stoneworts, the first plants were aquatic. They may have had stalks but not stems. They also may have had hair-like structures called rhizoids but not roots. The first plants probably had male and female reproductive organs and needed water to reproduce. In stoneworts, sperm need at least a thin film of moisture to swim to eggs. |
What is added to a measured portion of a more concentrated stock solution to achieve a particular concentration? | pigment | water | yeast | solvent | Dilution is also a common means of preparing solutions of a desired concentration. By adding solvent to a measured portion of a more concentrated stock solution, we can achieve a particular concentration. For example, commercial pesticides are typically sold as solutions in which the active ingredients are far more concentrated than is appropriate for their application. Before they can be used on crops, the pesticides must be diluted. This is also a very common practice for the preparation of a number of common laboratory reagents (Figure 3.17). |
What do humans and bats have physically in common? | body oder | wing size | gland hair | body hair | Both humans and bats have body hair, and both humans and bats can nurse their young. These are both characteristics of mammals, the class that both bats and humans belong to. |
Because optics fibers are thin, entering light may strike the inside surface at greater than the critical angle, requiring attention to what? | wavelength | reflective point | electromagnetic index | refractive index | Fiber Optics: Endoscopes to Telephones Fiber optics is one application of total internal reflection that is in wide use. In communications, it is used to transmit telephone, internet, and cable TV signals. Fiber optics employs the transmission of light down fibers of plastic or glass. Because the fibers are thin, light entering one is likely to strike the inside surface at an angle greater than the critical angle and, thus, be totally reflected (See Figure 25.14. ) The index of refraction outside the fiber must be smaller than inside, a condition that is easily satisfied by coating the outside of the fiber with a material having an appropriate refractive index. In fact, most fibers have a varying refractive index to allow more light to be guided along the fiber through total internal refraction. Rays are reflected around corners as shown, making the fibers into tiny light pipes. |
What is a vector quantity with the same direction as the force called? | simple | accelerated | inverted | impulse | Impulse is a vector quantity that has the same direction as the force. |
Club mosses, horsetails, ferns, and whisk ferns are examples of what type of plants? | angiosperms | cycads | gymnosperms | seedless vascular plants | Seedless Vascular Plants By the Late Devonian period (385 million years ago), plants had evolved vascular tissue, well-defined leaves, and root systems. With these advantages, plants increased in height and size. During the Carboniferous period (359–299 million years ago), swamp forests of club mosses and horsetails, with some specimens reaching more than 30 meters tall, covered most of the land. These forests gave rise to the extensive coal deposits that gave the Carboniferous its name. In seedless vascular plants, the sporophyte became the dominant phase of the lifecycle. Water is still required for fertilization of seedless vascular plants, and most favor a moist environment. Modern-day seedless vascular plants include club mosses, horsetails, ferns, and whisk ferns. Club Mosses The club mosses, or Lycophyta, are the earliest group of seedless vascular plants. They dominated the landscape of the Carboniferous period, growing into tall trees and forming large swamp forests. Today’s club mosses are diminutive, evergreen plants consisting of a stem (which may be branched) and small leaves called microphylls (Figure 14.13). The division Lycophyta consists of close to 1,000 species, including quillworts (Isoetales), club mosses (Lycopodiales), and spike mosses (Selaginellales): none of which is a true moss. |
What do seeds have that spores do not? | chlorophyll | DNA | pollenators | a supply of stored food | |
A vector is an organism that carries what disease-causing microorganisms from one person or animal to another? | genome | microbe | microbe | pathogen | Still other pathogens are spread by vectors . A vector is an organism that carries pathogens from one person or animal to another. Most vectors are insects, such as ticks and mosquitoes. These insects tend to transfer protozoan or viral parasites. When an insect bites an infected person or animal, it picks up the pathogen. Then the pathogen travels to the next person or animal it bites. Ticks carry the bacteria that cause Lyme disease. Mosquitoes ( Figure below ) carry West Nile virus. Both pathogens cause fever, headache, and tiredness. If the diseases are not treated, more serious symptoms may develop. Other diseases spread by mosquitoes include Dengue Fever and Yellow Fever. |
When explosion of gases creates pressure resulting in motion of a rocket, the force pushing the rocket is called what? | temperature | friction | stasis | thrust | For a long time, many people believed that a rocket wouldn’t work in space. There would be nothing for the rocket to push against. But they do work! Fuel is ignited in a chamber. The gases in the chamber explode. The explosion creates pressure that forces the gases out of one side of the rocket. The rocket moves in the opposite direction ( Figure below ). The force pushing the rocket is called thrust . |
What once most common bird in north america became extinct in the 1800s? | the rock penguin | the dodo | the homing piegon | the passenger piegon | Hundreds of species of birds have gone extinct as a result of human actions. A well-known example is the passenger pigeon. It was once the most common bird in North America, but overhunting and habitat destruction led to its extinction in the 1800s. Habitat destruction and use of the pesticide DDT explain the recent extinction of the dusky seaside sparrow. This native Florida bird was declared extinct in 1990. |
What is the process called where nitrogen is repeatedly recycled through the biosphere? | nitrogen path | ammonia cycle | water cycle | nitrogen cycle | Like water and carbon, nitrogen is also repeatedly recycled through the biosphere. This process is called the nitrogen cycle . Nitrogen is one of the most common elements in living organisms. It is important for creating both proteins and nucleic acids, like DNA. The air that we breathe is mostly nitrogen gas (N 2 ), but, unfortunately, animals and plants cannot use the nitrogen when it is a gas. In fact, plants often die from a lack of nitrogen even through they are surrounded by plenty of nitrogen gas. Nitrogen gas (N 2 ) has two nitrogen atoms connected by a very strong triple bond. Most plants and animals cannot use the nitrogen in nitrogen gas because they cannot break that triple bond. |
What does pepsin help break down into amino acids? | fats | glucose | carbohydrates | proteins | Pepsin, produced in the stomach. Pepsin helps break down proteins into amino acids. |
What are the most successful phylum of plants? | ferns | spores | gymnosperms | angiosperms | Angiosperms , in the phylum Anthophyta , are the most successful phylum of plants. This category also contains the largest number of individual plants ( Figure below ). Angiosperms evolved the structure of the flower, so they are also called the flowering plants. Angiosperms live in a variety of different environments. A water lily, an oak tree, and a barrel cactus, although different, are all angiosperms. |
The muscular layer is much thicker in which ventricle of the heart? | right | middle | upper | left | Left Ventricle Recall that, although both sides of the heart will pump the same amount of blood, the muscular layer is much thicker in the left ventricle compared to the right (see Figure 19.8). Like the right ventricle, the left also has trabeculae carneae, but there is no moderator band. The mitral valve is connected to papillary muscles via chordae tendineae. There are two papillary muscles on the left—the anterior and posterior—as opposed to three on the right. The left ventricle is the major pumping chamber for the systemic circuit; it ejects blood into the aorta through the aortic semilunar valve. |
In many places, small hills rise above the ocean floor. these hills are undersea volcanoes, called what? | ridges | reefs | corals | seamounts | The ocean floor is not totally flat. In many places, small hills rise above the ocean floor. These hills are undersea volcanoes, called seamounts ( Figure above ). Some rise more than 1000 m above the seafloor. |
Ants, termites, bees, and wasps live in what type of social structure that may include millions of individual insects? | community | family | habitat | colony | Many species of insects have evolved complex social behaviors. They live together in large, organized colonies (see Figure below ). This is true of ants, termites, bees, and wasps. Colonies may include millions of individual insects. Colony members divide up the labor of the colony. Different insects are specialized for different jobs. Some reproduce, while others care for the young. Still others get food or defend the nest. |
Schrödinger’s approach uses three quantum numbers (n, l, and ml) to specify any of what type of function, associated with a particular energy? | rush function | shift function | green function | wave function | Each wave function is associated with a particular energy. As in Bohr’s model, the energy of an electron in an atom is quantized; it can have only certain allowed values. The major difference between Bohr’s model and Schrödinger’s approach is that Bohr had to impose the idea of quantization arbitrarily, whereas in Schrödinger’s approach, quantization is a natural consequence of describing an electron as a standing wave. Quantum Numbers Schrödinger’s approach uses three quantum numbers (n, l, and ml) to specify any wave function. The quantum numbers provide information about the spatial distribution of an electron. Although n can be any positive integer, only certain values of l and ml are allowed for a given value of n. The Principal Quantum Number The principal quantum number (n) tells the average relative distance of an electron from the nucleus:. |
What is the term for the ability of an atom to emit, or give off, charged particles and energy from its nucleus? | conductivity | magnetism | electrical attraction | radioactivity | Radioactivity is the ability of an atom to emit, or give off, charged particles and energy from its nucleus. The charged particles and energy are called by the general term radiation . Only unstable nuclei emit radiation. They are unstable because they have too much energy, too many protons, or an unstable ratio of protons to neutrons. For example, all elements with more than 83 protons—such as uranium, radium, and polonium—have unstable nuclei. They are called radioactive elements. The nuclei of these elements must lose protons to become more stable. When they do, they become different elements. |
What type of fluid cushions the fetus and helps protect it from injury? | aqueous | plasmid | epithelial | amniotic | Another structure that supports the fetus is the amniotic sac. This is a membrane that surrounds and protects the fetus. It contains amniotic fluid, which consists of water and dissolved substances. The fluid allows the fetus to move freely until it grows to fill most of the available space. The fluid also cushions the fetus and helps protect it from injury. |
How can you prevent diseases such as whooping cough and flu? | vacuuming | nutrition | exercise | preventive vaccinations | Getting the recommended vaccinations can help prevent diseases, such as whooping cough and flu. In fact, a yearly flu vaccine is recommended for everyone who is at least 6 months of age. The flu vaccine is especially important for people who are at high risk of developing serious complications (like pneumonia) if they get sick with the flu. People who have certain medical conditions including asthma, diabetes, and chronic lung disease, pregnant women, and people younger than 5 years (and especially those younger than 2), and people 65 years and older should also make sure they get the yearly flu vaccine. |
Why do snakes have venomous bites? | to scare humans | to clean themselves | to kill rival snakes | to kill prey | Some snakes have a venomous bite, which they use to kill their prey before eating it. Other snakes kill their prey by strangling them, and still others swallow their prey whole and alive. After eating, snakes enter a resting stage, while the process of digestion takes place. The process is highly efficient, with the snake’s digestive enzymes dissolving and absorbing everything but the prey’s hair and claws!. |
Chelicerae in spiders are often modified into fangs that perform what function? | tearing flesh | courtship display | chewing | inject venom | Chelicerae are mostly used for feeding, but in spiders, these are often modified into fangs that inject venom into their prey before feeding (Figure 28.43). Members of this subphylum have an open circulatory system with a heart that pumps blood into the hemocoel. Aquatic species have gills, whereas terrestrial species have either trachea or book lungs for gaseous exchange. |
What results from uncontrolled cell division? | diabetes | high blood pressure | obesity | cancers | Many cancers result from uncontrolled cell division, when the regulation of the cycle is lost ( Figure below ). Recall that the cell cycle is the normal life of a cell. During this cycle, the cell performs its necessary functions, replicates its DNA and organelles, and divides through mitosis and cytokinesis, such that two genetically identical cells result. The cycle is highly regulated so that no phase proceeds before it is ready to do so. |
Where do angiosperms form seeds? | cones | stamen | testes | ovaries | Angiosperms, or flowering seed plants, form seeds in ovaries. As the seeds develop, the ovaries may develop into fruits. Flowers attract pollinators, and fruits encourage animals to disperse the seeds. |
What term is used to describe the development of new technology? | industrial design | mechanical engineering | technological expansion | technological design | Technological design is the development of new technology. The design process is based on evidence and logic. |
All of the populations that live in the same area make up what type of group, which includes populations of different organisms? | hive | environment | colony | community | All of the populations that live in the same area make up a community . The community that includes the goldfish population also includes the populations of other fish, coral, and other organisms. |
What model describing atomic structure is often referred to as a planetary model? | Pascal model | Newton's model | kinetic model | bohr model | According to the Bohr model, often referred to as a planetary model , the electrons encircle the nucleus of the atom in specific allowable paths called orbits. When the electron is in one of these orbits, its energy is fixed. The ground state of the hydrogen atom, where its energy is lowest, is when the electron is in the orbit that is closest to the nucleus. The orbits that are further from the nucleus are all of successively greater energy. The electron is not allowed to occupy any of the spaces in between the orbits. An everyday analogy to the Bohr model is the rungs of a ladder. As you move up or down a ladder, you can only occupy specific rungs and cannot be in the spaces in between rungs. Moving up the ladder increases your potential energy, while moving down the ladder decreases your energy. |
The medium moves back and forth in the same direction as the wave in what type of wave? | latitudinal wave | variable wave | kinetic wave | longitudinal wave | In a longitudinal wave, the medium moves back and forth in the same direction as the wave. |
A ramp is a type of simple machine called what? | rough plane | extension plane | allow plane | inclined plane | Look at the ramp in the Figure below . A ramp is a type of simple machine called an inclined plane. It can be used to raise an object off the ground. The input distance is the length of the sloped surface of the ramp. This is the distance over which the input force is applied. The output distance is the height of the ramp, or the vertical distance the object is raised. For this ramp, the input distance is 6 m and the output distance is 2 meters. Therefore, the ideal mechanical advantage of this ramp is:. |
Where do plants take in air? | their roots | their flowers | their stems | their leaves | |
Under the right conditions, what energy source can be used to eject electrons from a solid material? | gravity | force | weight | light | Under the right conditions, light can be used to eject electrons from a solid material. |
The type of bond that forms between molecules is called what? | helium bond | fission bond | covalent bond | hydrogen bond | Opposites attract when it comes to charged molecules. In the case of water, the positive (hydrogen) end of one water molecule is attracted to the negative (oxygen) end of a nearby water molecule. Because of this attraction, weak bonds form between adjacent water molecules, as shown in Figure below . The type of bond that forms between molecules is called a hydrogen bond . Bonds between molecules are not as strong as bonds within molecules, but in water they are strong enough to hold together nearby molecules. |
Radiation, chemicals, and infectious agents are examples of what? | pathogens | inhibitors | catalysts | mutagens | Examples of Mutagens. Types of mutagens include radiation, chemicals, and infectious agents. Do you know of other examples of each type of mutagen shown here?. |
What is the name for a tool commonly used by molecular biologists to place genetic material into cells? | a dna vector | a embryonic vector | an rna vector | a viral vector | Geneticists often use viruses as vectors to introduce genes into cells that they are studying. A viral vector is a tool commonly used by molecular biologists to place genetic material into cells. To be a useful viral vector, the virus is modified so that it will not cause disease, and it will infect only certain types of cells. Phages are often used as vectors to genetically modify bacteria. |
What is the study of how forces affect the motion of objects? | kinematics | behaviors | acceleration | dynamics | Section Summary 4.1 Development of Force Concept • Dynamics is the study of how forces affect the motion of objects. • Force is a push or pull that can be defined in terms of various standards, and it is a vector having both magnitude and direction. • External forces are any outside forces that act on a body. A free-body diagram is a drawing of all external forces acting on a body. |
Compounds containing which element are the basis of all known life? | hydrogen | oxygen | helium | carbon | Carbon has the ability to form very long chains of interconnecting C-C bonds. This property allows carbon to form the backbone of organic compounds , carbon-containing compounds, which are the basis of all known organic life. Nearly 10 million carbon-containing organic compounds are known. Types of carbon compounds in organisms include carbohydrates, lipids, proteins, and nucleic acids. The elements found in each type are listed in the table below. Elements other than carbon and hydrogen usually occur within organic compounds in smaller groups of elements called functional groups . When organic compounds react with other compounds, generally just the functional groups are involved. Therefore, functional groups generally determine the nature and functions of organic compounds. |
What type of rocks form when an existing rock is changed by heat or pressure? | sediments | Molten | igneous | metamorphic | 3. Metamorphic rocks form when an existing rock is changed by heat or pressure. The minerals in the rock change but do not melt ( Figure below ). The rock experiences these changes within the Earth. |
What does jupiter reflect a lot of due to its size? | moisture | carbon | molecules | sunlight | Jupiter is truly a giant! The planet has 318 times the mass of Earth, and over 1,300 times Earth’s volume. So Jupiter is much less dense than Earth. Because Jupiter is so large, it reflects a lot of sunlight. When it is visible, it is the brightest object in the night sky besides the Moon and Venus. Jupiter is quite far from Earth. The planet is more than five times as far from Earth as the Sun. It takes Jupiter about 12 Earth years to orbit once around the Sun. |