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What is the first step in protein synthesis? | mutation | reproduction | differentiation | transcription | Transcription is the first step in protein synthesis. It takes place in the nucleus. During transcription, a strand of DNA is copied to make a strand of mRNA. How does this happen? It occurs by the following steps, as shown in Figure below . |
What branch of biology focuses on heredity? | semiotics | Epidemiology | ontology | genetics | Genetics is the branch of biology that focuses on heredity. The basics of heredity are similar for all organisms that reproduce sexually: the offspring receive one set of genetic material from one parent and the other set from the other parent. But are there aspects of genetics that are specific for humans? Let’s find out. |
Stars are born in clouds, and they form and grow dense due to what force? | coreolis effect | kinetic energy | Big Bang theory | gravity | Stars are born in clouds like the one in the picture. Gravity pulls material together. When it is extremely dense, it begins nuclear fusion. That is, it becomes a star. We can see places where stars are being born right now. Of course, it takes light a long time to travel to us. So what we see right now may have happened many millions or even billions of years ago. |
What has atoms with unstable nuclei? | radionuclide | hydrocarbon | microwaves | radioisotope | A radioisotope has atoms with unstable nuclei. Unstable nuclei naturally decay, or break down. They lose energy and particles and become more stable. As nuclei decay, they gain or lose protons, so the atoms become different elements. This is illustrated in the Figure below . The original, unstable nucleus is called the parent nucleus. After it loses a particle (in this case a type of particle called an alpha particle), it forms a daughter nucleus, with a different number of protons. |
What is the tissue beneath a mollusks' shell called? | mucous | cartilage | skin | mantle | Mollusks have ventral nerve cords. The tissue beneath the shell is called the mantle. The mantle cavity contains hemolymph. Figure 15.33 Which of the following statements about common features of chordates is true? a. The dorsal hollow nerve cord is part of the chordate central nervous system. In vertebrate fishes, the pharyngeal slits become the gills. Humans are not chordates because humans do not have a tail. Vertebrates do not have a notochord at any point in their development; instead, they have a vertebral column. |
What is formed from an alcohol that loses water? | amines | Bonds | alcohols | alkenes | Alcohols can lose water to form alkenes. |
What is the division of the body into multiple parts called? | organ-level organization | compression | transverse | segmentation | Segmentation evolved next. This is a division of the body into multiple segments. Both the earthworm and ant pictured in Figure below have segmented bodies. This trait increases flexibility. It permits a wider range of motion. All annelids and arthropods are segmented. Arthropods also evolved jointed appendages. For example, they evolved jointed legs for walking and “feelers” (antennae) for sensing. |
What reproductive method has two parents involved? | budding | mitosis | pollination | sexually | Most reptiles reproduce sexually, meaning there are two parents involved. In some families of lizards and one snake family, however, asexual reproduction is possible. This is when only one parent is involved in creating new life. For example, the gecko females can make tiny clones of themselves without the aid of a male. |
In many cases, the alkali metal amide salt (mnh2) is not very soluble in liquid ammonia and does what? | evaporates | settles | isolates | precipitates | where the (am) designation refers to an ammonia solution, analogous to (aq) used to indicate aqueous solutions. Without a catalyst, the reaction in Equation 21.20 tends to be rather slow. In many cases, the alkali metal amide salt (MNH2) is not very soluble in liquid ammonia and precipitates, but when dissolved, very concentrated solutions of the alkali metal are produced. One mole of Cs metal, for example, will dissolve in as little as 53 mL (40 g) of liquid ammonia. The pure metal is easily recovered when the ammonia evaporates. Solutions of alkali metals in liquid ammonia are intensely colored and good conductors of electricity due to the presence of solvated electrons (e−, NH3), which are not attached to single atoms. A solvated electron is loosely associated with a cavity in the ammonia solvent that is stabilized by hydrogen bonds. Alkali metal–liquid ammonia solutions of about 3 M or less are deep blue (Figure 21.11 "Alkali Metal–Liquid Ammonia Solutions") and conduct electricity about 10 times better than an aqueous NaCl solution because of the high mobility of the solvated electrons. As the concentration of the metal increases above 3 M, the color changes to metallic bronze or gold, and the conductivity increases to a value comparable with that of the pure liquid metals. |
An example of beta decay is the emission of an electron by a carbon-14 what? | protons | molecules | ion | nucleus | Transmutation also occurs when a nucleus undergoes decay. An example of beta decay is the emission of an electron by a carbon-14 nucleus. |
Which theory describes the distribution of electrons in molecules in much the same way that the distribution of electrons in atoms is described using atomic orbitals? | atomic distribution theory | molecular distribution theory | atomic orbital theory | molecular orbital theory | Molecular orbital theory describes the distribution of electrons in molecules in much the same way that the distribution of electrons in atoms is described using atomic orbitals. Using quantum mechanics, the behavior of an electron in a molecule is still described by a wave function, Ψ, analogous to the behavior in an atom. Just like electrons around isolated atoms, electrons around atoms in molecules are limited to discrete (quantized) energies. The region of space in which a valence electron in a molecule is likely to be found is called a molecular orbital (Ψ2). Like an atomic orbital, a molecular orbital is full when it contains two electrons with opposite spin. We will consider the molecular orbitals in molecules composed of two identical atoms (H2 or Cl2, for example). Such molecules are called homonuclear diatomic molecules. In these diatomic molecules, several types of molecular orbitals occur. The mathematical process of combining atomic orbitals to generate molecular orbitals is called the linear combination of atomic orbitals (LCAO). The wave function describes the wavelike properties of an electron. Molecular orbitals are combinations of atomic orbital wave functions. Combining waves can lead to constructive interference, in which peaks line up with peaks, or destructive interference, in which peaks line up with troughs. |
Oversecretion of insulin can cause what? | hypoxia | hyperglycemia | inflammation | hypoglycemia | This animation (http://openstaxcollege. org/l/insulin) describe the role of insulin and the pancreas in diabetes. Impaired insulin function can lead to a condition called diabetes mellitus, the main symptoms of which are illustrated in Figure 37.10. This can be caused by low levels of insulin production by the beta cells of the pancreas, or by reduced sensitivity of tissue cells to insulin. This prevents glucose from being absorbed by cells, causing high levels of blood glucose, or hyperglycemia (high sugar). High blood glucose levels make it difficult for the kidneys to recover all the glucose from nascent urine, resulting in glucose being lost in urine. High glucose levels also result in less water being reabsorbed by the kidneys, causing high amounts of urine to be produced; this may result in dehydration. Over time, high blood glucose levels can cause nerve damage to the eyes and peripheral body tissues, as well as damage to the kidneys and cardiovascular system. Oversecretion of insulin can cause hypoglycemia, low blood glucose levels. This causes insufficient glucose availability to cells, often leading to muscle weakness, and can sometimes cause unconsciousness or death if left untreated. |
The first few species to colonize a disturbed area are called what? | colonization species | producer species | original species | pioneer species | The first few species to colonize a disturbed area are called pioneer species. In primary succession, pioneer species must be organisms that can live on bare rock. They usually include bacteria and lichens (see Figure below ). Along with wind and water, the pioneer species help weather the rock and form soil. Once soil begins to form, plants can move in. The first plants are usually grasses and other small plants that can grow in thin, poor soil. As more plants grow and die, organic matter is added to the soil. This improves the soil and helps it hold water. The improved soil allows shrubs and trees to move into the area. |
What are the two loops of blood flow in the cardiovascular system? | systolic and diastolic | anabolic and metabolic | aerobic and anaerobic | pulmonary and systemic | The cardiovascular system circulates blood through two different loops. Pulmonary circulation is a loop that carries blood between the heart and lungs. Systemic circulation is a loop that carries blood between the heart and the rest of the body. |
What is the name of a group of hereditary diseases that affect the body's ability to control blood clotting? | hypertension | arithmya | anemia | hemophilia | Hemophilia is the name of a group of hereditary diseases that affect the body's ability to control blood clotting. Hemophilia is caused by a lack of clotting factors in the blood. Clotting factors are normally released by platelets. Since people with hemophilia cannot produce clots, any cut can put a person at risk of bleeding to death. The risk of internal bleeding is also increased in hemophilia, especially into muscles and joints. This disease affected the royal families of Europe. |
Protists which use their tails to eat are called what? | flagellators | swimmers | cycle - feeders | filter-feeders | Some animal-like protists use their "tails" to eat. These protists are called filter-feeders . They acquire nutrients by constantly whipping their tails, called flagellum , back and forth. The whipping of the flagellum creates a current that brings food into the protist. |
What term is used to describe foods containing active cultures of beneficial bacteria? | carotenoids | sembiotic | antibiotics | probiotic | Yogurt is a good source of calcium. Yogurt also contains active cultures of "good" bacteria. Foods that contain these beneficial bacteria are sometimes called "probiotic. ". |
What helps control the muscles and maintain balance? | lymphatic system | circulatory system | muscular system | nervous system | Staying balanced when riding a scooter requires control over the body’s muscles. The nervous system controls the muscles and maintains balance. |
What unit of power is equal to 1 joule of energy per second? | volt | hertz | byte | watt | The rate at which a device changes electric current to another form of energy is called electric power . The SI unit for power—including electric power—is the watt. A watt equals 1 joule of energy per second. High wattages are often expressed in kilowatts, where 1 kilowatt equals 1000 watts. The power of an electric device, such as a hair dryer, can be calculated if you know the voltage of the circuit and how much current the device receives. The following equation is used:. |
What is just below the cerebrum and coordinates body movements? | spinal cord | hypothalamus | bloodstream | cerebellum | The cerebellum is just below the cerebrum. It coordinates body movements. Many nerve pathways link the cerebellum with motor neurons throughout the body. |
What part of blood releases clotting factors? | erythrocytes | hemoglobin | white blood cells | platelets | Platelets ( Figure below ) are very small, but they are very important in blood clotting. Platelets are not cells. They are sticky little pieces of larger cells. Platelets bud off large cells that stay in the bone marrow. When a blood vessel gets cut, platelets stick to the injured areas. They release chemicals called clotting factors, which cause proteins to form over the wound. This web of proteins catches red blood cells and forms a clot. This clot stops more blood from leaving the body through the cut blood vessel. The clot also stops bacteria from entering the body. Platelets survive in the blood for ten days before they are removed by the liver and spleen. |
Adding carbon to iron makes what type of metal? | plastic | ions | titanium | steel | Metals such as iron are useful for many purposes because of their unique properties. For example, they can conduct electricity and bend without breaking. However, pure metals may be less useful than mixtures of metals with other elements. For example, adding a little carbon to iron makes it much stronger. This mixture is called steel. Steel is so strong that it can hold up huge bridges, like the one pictured above. Steel is also used to make skyscrapers, cargo ships, cars, and trains. Steel is an example of an alloy. |
Which structure includes sugar-phosphate "backbones", composed of alternating phosphate groups and deoxyribose sugars, and nitrogenous bases? | dna triple helix | molecule double helix | mulecular triplex | dna double helix | The DNA double helix. The two sides are the sugar-phosphate backbones, composed of alternating phosphate groups and deoxyribose sugars. The nitrogenous bases face the center of the double helix. As the base-pairing rules tell us, A always pairs with T, and G always pairs with C. |
In a hydrogen replacement reaction, the hydrogen in the acid is replaced by what? | oxygen | gas | water | an active metal | In a hydrogen replacement reaction, the hydrogen in the acid is replaced by an active metal. |
Mitosis and meiosis are both forms of division of the nucleus in these? | reproduction cells | converts cells | endogenous cells | eukaryotic cells | Comparing Meiosis and Mitosis Mitosis and meiosis are both forms of division of the nucleus in eukaryotic cells. They share some similarities, but also exhibit distinct differences that lead to very different outcomes (Figure 11.7). Mitosis is a single nuclear division that results in two nuclei that are usually partitioned into two new cells. The nuclei resulting from a mitotic division are genetically identical to the original nucleus. They have the same number of sets of chromosomes, one set in the case of haploid cells and two sets in the case of diploid cells. In most plants and all animal species, it is typically diploid cells that undergo mitosis to form new diploid cells. In contrast, meiosis consists of two nuclear divisions resulting in four nuclei that are usually partitioned into four new cells. The nuclei resulting from meiosis are not genetically identical and they contain one chromosome set only. This is half the number of chromosome sets in the original cell, which is diploid. |
What is the last step in a scientific investigation? | retesting findings | documenting findings | verifying findings | communicating findings | The last step in a scientific investigation is communicating what you have learned with others. This is a very important step because it allows others to test your hypothesis. If other researchers get the same results as yours, they add support to the hypothesis. However, if they get different results, they may disprove the hypothesis. When scientists share their results, they should describe their methods and point out any possible problems with the investigation. Results can be communicated in various ways. A scientist usually contributes material through publication in a peer-reviewed scientific journal. Peer-review ensures the material is of an acceptable quality for the scientific community. Scientists also write review articles, book chapters, and even whole books. They also regularly participate in scientific meetings, presenting their material in front of large audiences of their peers. |
Where is multiple fission more often observed? | among vertebrates | among multi-celled organisms | among animals | among protists | Binary fission in various single-celled organisms (left). Cell division is a relatively simple process in many single-celled organisms. Eventually the parent cell will pinch apart to form two identical daughter cells. In multiple fission (right), a multinucleated cell can divide to form more than one daughter cell. Multiple fission is more often observed among protists. |
What type of invertebrates where the earliest animals? | annelids | cnidaria | arachnids | aquatic invertebrates | The oldest animal fossils are about 630 million years old. The earliest animals were aquatic invertebrates. The first vertebrates evolved around 550 million years ago. By 500 million years ago, most modern phyla of animals had evolved. |
Unlike wood and glass, steel is an example of a material that responds to what force? | thermal | kinetic | electromagnetic | magnetic | Magnetism is the ability of a material to be attracted by a magnet and to act as a magnet. No doubt you’ve handled refrigerator magnets like the ones in Figure below . You probably know first-hand that they stick to a metal refrigerator but not to surfaces such as wooden doors and glass windows. Wood and glass aren’t attracted to a magnet, whereas the steel refrigerator is. Obviously, only certain materials respond to magnetic force. |
Carefully controlling the speed of a fission reaction produces what kind of energy? | thermal | chemical | atomic | nuclear | Nuclear energy is produced by carefully controlling the speed of a fission reaction. |
When two electric contacts come together it completes a what? | atom | charge | breaker | cricuit | Figure below shows a diagram of a simple doorbell. Like most doorbells, it has a button located by the front door. Pressing the button causes two electric contacts to come together and complete an electric circuit. In other words, the button is a switch. The circuit is also connected to a voltage source, an electromagnet, and the clapper of a bell. When current flows through the circuit, the electromagnet turns on, and its magnetic field attracts the clapper. This causes the clapper to hit the bell, making it ring. Because the clapper is part of the circuit, when it moves to strike the bell, it breaks the circuit. Without current flowing through the circuit, the electromagnet turns off. The clapper returns to its original position, which closes the circuit again and turns the electromagnet back on. The electromagnet again attracts the clapper, which hits the bell once more. This sequence of events keeps repeating as long as the button by the front door is being pressed. |
Pure nonpolar covalent bonds exist only between what? | three altered atoms | two altered atoms | two producing atoms | two identical atoms | Pure nonpolar covalent bonds exist only between two identical atoms. The H-H bond would be 100% covalent, because there is no difference in electronegativity between the two atoms. |
The decay rate is measured in a unit called the what? | radioactive decay | decay rate | exponential decay | half-life | The decay of an unstable isotope to a stable element occurs at a constant rate. This rate is different for each isotope pair. The decay rate is measured in a unit called the half-life. The half-life is the time it takes for half of a given amount of an isotope to decay. For example, the half-life of carbon-14 is 5730 years. Imagine that you start out with 100 grams of carbon-14. In 5730 years, half of it decays. This leaves 50 grams of carbon-14. Over the next 5730 years, half of the remaining amount will decay. Now there are 25 grams of carbon-14. How many grams will there be in another 5730 years? Figure below graphs the rate of decay of carbon-14. |
What is a condition in which a material called plaque builds up inside arteries? | arthritis | scoliosis | fibrosis | atherosclerosis | Atherosclerosis is a condition in which a material called plaque builds up inside arteries. Plaque consists of cell debris, cholesterol, and other substances. As plaque builds up in an artery, the artery narrows, as shown in Figure below . This reduces blood flow through the artery. |
Quarks in the middle energy family are found in cosmic rays and are produced in what? | particle splicers | particle processors | cosmic accelerators | particle accelerators | Everyday objects are made up of quarks from the lowest energy family, namely up and down quarks. Quarks in the middle energy family are found in cosmic rays and are produced in particle accelerators. Particles in the high energy family are believed to have existed briefly during the earliest moments of the Big Bang and are created only in high energy collisions. |
What celestial body in the solar system makes up most of its total mass? | Andromeda | Jupiter | earth | sun | The Sun makes up almost all of the mass of the solar system. |
Free ear lobes, widow's peak and a dimpled chin are examples of what kind of traits in humans? | spontaneous mutations | genetic disorders | adaptations | mendelian | In many instances, the relationship between genes and inheritance is more complex than that which Mendel found. Nevertheless, geneticists have since found that Mendel’s findings can be applied to many organisms. For example, there are clear patterns of Mendelian inheritance in humans. These include the inheritance of normal characteristics and characteristics that occur less often. Easily observable Mendelian traits in humans include free ear lobes (in most people the ear lobes hang free (dominant), whereas the attached earlobe is recessive), hitchhiker's thumb (a straight thumb is dominant, while a bent thumb is recessive), widow's peak (a hairline with a distinct point in the middle of the forehead is dominant, while a straight hairline is recessive), dimpled chin (a cleft in the chin is dominant, whereas the absence of a cleft is recessive), and mid-digital hair (hair on any middle segments of the fingers is dominant). Of course, many severe human phenotypes are inherited in a Mendelian fashion including Phenylketonuria (PKU), cystic fibrosis, Huntington's disease, hypercholesterolemia, and sickle-cell anemia. These are termed genetic disorders and will be discussed in additional concepts. |
Producing light without heat is called what? | bioluminescence | osmosis | thermoluminescence | luminescence | The sun and other stars produce light because they are so hot. They glow with light due to their extremely high temperatures. This way of producing light is called incandescence . Some objects produce light without becoming very hot. They generate light through chemical reactions or other processes. Producing light without heat is called luminescence . Objects that produce light by luminescence are said to be luminous. Luminescence, in turn, can occur in different ways:. |
What natural part of the water cycle can cause damage and death? | expiration | clouds | evaporation | floods | Floods are a natural part of the water cycle, but they can cause a lot of damage. Farms and homes may be lost, and people may die. In 1939, millions of people died in a flood in China. Although freshwater is needed to grow crops and just to live, too much freshwater in the same place at once can be deadly. |
How many large eggs are generated during oogenesis? | 4 | 3 | 2 | one | |
Gaseous nitrogen is converted into forms that can be used by plants during a process called what? | plant fixation | oxygen fixation | dioxide fixation | nitrogen fixation | Gaseous nitrogen is converted into forms that can be used by plants during the process of nitrogen fixation. |
What is an example of a disease that affects the blood? | rickets | scoliosis | tuberculosis | anemia | Many diseases affect the blood or its components. They include anemia, leukemia, hemophilia, and sickle-cell disease. |
Name the term used to described prokaryotes that require oxygen. | mouth breathers | anaerobic | hydrophylic | aerobic | Prokaryotes that need oxygen are described as aerobic. They use oxygen for cellular respiration. Examples include the prokaryotes that live on your skin. |
Many ionic compounds with relatively large cations and a 1:1 cation:anion ratio have this structure, which is called the what? | analogous structure | boron chloride structure | hydrocarbon structure | cesium chloride structure | Common Structures of Binary Compounds As shown in part (a) in Figure 12.8 "Holes in Cubic Lattices", a simple cubic lattice of anions contains only one kind of hole, located in the center of the unit cell. Because this hole is equidistant from all eight atoms at the corners of the unit cell, it is called acubic hole. An atom or ion in a cubic hole therefore has a coordination number of 8. Many ionic compounds with relatively large cations and a 1:1 cation:anion ratio have this structure, which is called the cesium chloride structure (Figure 12.9 "The Cesium Chloride Structure") because CsCl is a common example. |
What property increases as an object's mass increases, making a full box harder to push than an empty one? | magnetism | weight | gravity | inertia | The inertia of an object depends on its mass. Objects with greater mass also have greater inertia. Think how hard it would be to push a big box full of books, like the one in Figure below . Then think how easy it would be to push the box if it was empty. The full box is harder to move because it has greater mass and therefore greater inertia. |
What will happen to sea levels due to increased global temperatures? | surge | Drop | reverse | rise | This increase in global temperature will cause the sea level to rise. It is also expected to produce an increase in extreme weather events and change the amount of precipitation. Global warming may also cause food shortages and species extinction. |
Sea-lilies, sea cucumbers and sea stars fall into what class of organism? | crabs | snakes | mollusks | echinoderms | While almost all echinoderms live on the sea floor, some sea-lilies can swim at great speeds for brief periods of time, and a few sea cucumbers are fully floating. Some echinoderms find other ways of moving. For example, crinoids attach themselves to floating logs, and some sea cucumbers move by attaching to the sides of fish. |
What kind of rock forms when material such as gravel, sand, silt or clay is compacted and cemented together? | craters | ingenious | limestone | sedimentary | 2. Sedimentary rocks form when sediments are compacted and cemented together ( Figure below ). These sediments may be gravel, sand, silt or clay. Sedimentary rocks often have pieces of other rocks in them. Some sedimentary rocks form the solid minerals left behind after a liquid evaporates. |
In science, we need to make observations on various phenomena to form and test what? | variations | assumptions | theories | hypotheses | In science, we need to make observations on various phenomena to form and test hypotheses. Some phenomena can be found and studied in nature, but scientists often need to create an experiment . Experiments are tests under controlled conditions designed to demonstrate something scientists already know or to test something scientists wish to know. Experiments vary greatly in their goal and scale, but always rely on repeatable procedure and logical analysis of the results. The process of designing and performing experiments is a part of the scientific method. |
What do industries use water to generate? | light | pollution | refrigeration | electricity | Rechargeable batteries are renewable because they can be refilled with energy. Is the energy they are refilled with always renewable?. |
Mammals are synapsids, meaning they have a single opening in what structure? | hip | spine | heart | skull | Evolution of Mammals Mammals are synapsids, meaning they have a single opening in the skull. They are the only living synapsids, as earlier forms became extinct by the Jurassic period. The early non-mammalian synapsids can be divided into two groups, the pelycosaurs and the therapsids. Within the therapsids, a group called the cynodonts are thought to be the ancestors of mammals (Figure 29.36). |
What are the properties of solutions called that depend only on the concentration of dissolved particles and not on their identity? | platyhelminth properties | platyhelminth properties | platyhelminth properties | colligative properties | The vapor pressure of a solution is lower than that of the pure solvent at the same temperature. This decrease in vapor pressure is one example of a colligative property . Colligative properties are properties of solutions that depend only on the concentration of dissolved particles and not on their identity. |
Liquids that mix with each other in all proportions are said to be miscible, maning they have infinite mutual what? | salinity | viscosity | insolubility | solubility | Solutions of Liquids in Liquids We know that some liquids mix with each other in all proportions; in other words, they have infinite mutual solubility and are said to be miscible. Ethanol, sulfuric acid, and ethylene glycol (popular for use as antifreeze, pictured in Figure 11.14) are examples of liquids that are completely miscible with water. Two-cycle motor oil is miscible with gasoline. |
Which law relates the pressure, volume, and temperature of a gas? | newton's law | directions gas law | shifts gas law | combines gas law | The combined gas law relates pressure, volume, and temperature of a gas. |
Heat and light are forms of what, which refers to the ability to do work? | waves | fuel | food | energy | Energy is the ability to do work. Heat and light are forms of energy. Energy can change form. It can also move from place to place. |
Volcano chains form as an oceanic plate moves over what? | melt spot | dust spot | Water spot | hot spot | A chain of volcanoes forms as an oceanic plate moves over a hot spot. This is how it happens. A volcano forms over the hotspot. Since the plate is moving, the volcano moves off of the hotspot. When the hotspot erupts again, a new volcano forms over it. This volcano is in line with the first. Over time, there is a line of volcanoes. The youngest is directly above the hot spot. The oldest is the furthest away ( Figure below ). |
What type of planet is jupiter? | a red dwarf | a noble gas | a phantom | a gas giant | Since Jupiter is a gas giant, could a spacecraft land on its surface? The answer is no. There is no solid surface at all! Jupiter is made mostly of hydrogen, with some helium, and small amounts of other elements. The outer layers of the planet are gas. Deeper within the planet, the intense pressure condenses the gases into a liquid. Jupiter may have a small rocky core at its center. |
What does antifreeze do to the freezing temperature of the water in car radiators? | foresees it | raises it | keeps it constant | lowers it | Flickr:EvelynGiggles. Antifreeze lowers the freezing temperature of the water in car radiators . CC BY 2.0. |
What process typically occurs to metal exposed to outside elements? | explosion | shrinkage | extraction | corrosion | Metal exposed to the outside elements will usually corrode if not protected. The corrosion process is a series of redox reactions involving the metal of the sculpture. In some situations, the metals are deliberately left unprotected so that the surface will undergo changes that may enhance the esthetic value of the work. |
The innermost layer of the sun is known as what? | convective zone | photosphere | surface | core | The core is the Sun's innermost layer. The core is plasma. It has a temperature of around 15 million degrees Celsius (°C). Nuclear fusion reactions create the immense temperature. In these reactions, hydrogen atoms fuse to form helium. This releases vast amounts of energy. The energy moves toward the outer layers of the Sun. Energy from the Sun's core powers most of the solar system. |
Motor neurons and sensory neurons are part of what nervous system? | autonomic | peripheral | central | sensory-somatic | Sensory-Somatic Nervous System The sensory-somatic nervous system is made up of cranial and spinal nerves and contains both sensory and motor neurons. Sensory neurons transmit sensory information from the skin, skeletal muscle, and sensory organs to the CNS. Motor neurons transmit messages about desired movement from the CNS to the muscles to make them contract. Without its sensorysomatic nervous system, an animal would be unable to process any information about its environment (what it sees, feels, hears, and so on) and could not control motor movements. Unlike the autonomic nervous system, which has two synapses between the CNS and the target organ, sensory and motor neurons have only one synapse—one ending of the neuron is at the organ and the other directly contacts a CNS neuron. Acetylcholine is the main neurotransmitter released at these synapses. Humans have 12 cranial nerves, nerves that emerge from or enter the skull (cranium), as opposed to the spinal nerves, which emerge from the vertebral column. Each cranial nerve is accorded a name, which are detailed in Figure 35.28. Some cranial nerves transmit only sensory information. For example, the olfactory nerve transmits information about smells from the nose to the brainstem. Other cranial nerves transmit almost solely motor information. For example, the oculomotor nerve controls the opening and closing of the eyelid and some eye movements. Other cranial nerves contain a mix of sensory and motor fibers. For example, the glossopharyngeal nerve has a role in both taste (sensory) and swallowing (motor). |
What type of science is the study of matter and energy and includes chemistry and physics? | genetics | biology | Earth science | physical science | Physical science is the study of matter and energy. It includes chemistry and physics. |
When plants lose their leaves in the fall, what chemical is produced less to cause the change? | oxygen | pheromes | carbonate | chlorophyll | Even if you don’t live in a place where leaves turn color in the fall, no doubt you’ve seen photos of their “fall colors” (see Figure below ). The leaves of many plants turn from green to other, glorious colors during autumn each year. The change is triggered by shorter days and cooler temperatures. Leaves respond to these environmental stimuli by producing less chlorophyll . This allows other leaf pigments—such as oranges and yellows—to be seen. |
In which kind of animals does parthenogenesis occur? | species | tissues | mammals | invertebrates | Note that in fragmentation, there is generally a noticeable difference in the size of the individuals, whereas in fission, two individuals of approximate size are formed. Parthenogenesis Parthenogenesis is a form of asexual reproduction where an egg develops into a complete individual without being fertilized. The resulting offspring can be either haploid or diploid, depending on the process and the species. Parthenogenesis occurs in invertebrates such as water flees, rotifers, aphids, stick insects, some ants, wasps, and bees. Bees use parthenogenesis to produce haploid males (drones) and diploid females (workers). If an egg is fertilized, a queen is produced. The queen bee controls the reproduction of the hive bees to regulate the type of bee produced. Some vertebrate animals—such as certain reptiles, amphibians, and fish—also reproduce through parthenogenesis. Although more common in plants, parthenogenesis has been observed in animal species that were segregated by sex in terrestrial or marine zoos. Two female Komodo dragons, a hammerhead shark, and a blacktop shark have produced parthenogenic young when the females have been isolated from males. |
What is the name of the temporary organ that begins to form from the trophoblast layer of cells shortly after implantation? | appendix | uterus | embryo | placenta | The placenta is a temporary organ that begins to form from the trophoblast layer of cells shortly after implantation. (For an animation showing how the placenta forms, go to link below. ) The placenta continues to develop and grow to meet the needs of the growing fetus. A fully developed placenta, like the one in Figure above , is made up of a large mass of blood vessels from both the mother and fetus. The maternal and fetal vessels are close together but separated by tiny spaces. This allows the mother’s and fetus’s blood to exchange substances across their capillary walls without the blood actually mixing. |
What term is used to describe anything that takes up space and has mass? | opacity | size | weight | matter | If you look at your hand, what do you see? Of course, you see skin, which consists of cells. But what are skin cells made of? Like all living cells, they are made of matter. In fact, all things are made of matter. Matter is anything that takes up space and has mass. Matter, in turn, is made up of chemical substances. In this lesson you will learn about the chemical substances that make up living things. |
What is the organ that senses sound? | skin | nose | eye | ear | Hearing is the ability to sense sound waves, and the ear is the organ that senses sound. Sound waves enter the auditory canal and travel to the eardrum (see Figure below ). They strike the eardrum and make it vibrate. The vibrations then travel through several other structures inside the ear and reach the cochlea. The cochlea is a coiled tube filled with liquid. The liquid moves in response to the vibrations, causing tiny hair cells lining the cochlea to bend. In response, the hair cells send nerve impulses to the auditory nerve , which carries the impulses to the brain. The brain interprets the impulses and “tells” us what we are hearing. |
What can be described in terms of size, density, and distribution? | dimensions | habitats | biomes | populations | Populations can be described in terms of size, density, and distribution. Population growth may be exponential or logistic. The age-sex structure of a population affects the rate of population growth. |
What is the term for the simplest form of matter that has a unique set of properties? | a neutron | an electron | an atom | an element | An element is the simplest form of matter that has a unique set of properties. Examples of well-known elements include oxygen, iron, and gold (see the figure below). Elements cannot be broken down into a simpler substance. Likewise, one element cannot be chemically converted into a different element. |
What causes light to refract? | bending | speeding up | blinking | slowing down | Light slows down when it enters water from the air. This causes the wave to refract, or bend. |
Capacitors can be used to filter out low frequencies. for example, a capacitor in series with a sound reproduction system rids it of the 60 hz what? | echo | white noise | vibration | hum | the current. Capacitors can be used to filter out low frequencies. For example, a capacitor in series with a sound reproduction system rids it of the 60 Hz hum. |
What is made up of nerve cells that sense stimuli and transmit signals? | dependent tissue | muscle tissues | blood tissue | nervous tissue | Nervous tissue is made up of nerve cells that sense stimuli and transmit signals. Nervous tissue is found in nerves, the spinal cord, and the brain. |
Some animals prepare for the long winter by going into what? | pollination | suspended animation | fermentation | hibernation | |
It may seem as though burning destroys matter, but the same amount of what, still exists after a campfire as before? | energy | termperature | concentrations | mass | It may seem as though burning destroys matter, but the same amount, or mass, of matter still exists after a campfire as before. Look at the sketch in Figure below . It shows that when wood burns, it combines with oxygen and changes not only to ashes but also to carbon dioxide and water vapor. The gases float off into the air, leaving behind just the ashes. Suppose you had measured the mass of the wood before it burned and the mass of the ashes after it burned. Also suppose you had been able to measure the oxygen used by the fire and the gases produced by the fire. What would you find? The total mass of matter after the fire would be the same as the total mass of matter before the fire. |
Different isotopes of an element have different mass numbers because they have different numbers of what? | nuclei | protons | electrons | neutrons | An atom’s mass number is its mass in atomic mass units (amu), which is about equal to the total number of protons and neutrons in the atom. Different isotopes of an element have different mass numbers because they have different numbers of neutrons. |
Density is defined as the mass of an object divided by its what? | growth | size | liquid | volume | Density is defined as the mass of an object divided by its volume. Propose a unit of density in terms of the fundamental SI units. |
What element is responsible for one-half of the osmotic pressure gradient that exists between the interior of cells and their surrounding environment? | nitrogen | calcium | potassium | sodium | Sodium Sodium is the major cation of the extracellular fluid. It is responsible for one-half of the osmotic pressure gradient that exists between the interior of cells and their surrounding environment. People eating a typical Western diet, which is very high in NaCl, routinely take in 130 to 160 mmol/day of sodium, but humans require only 1 to 2 mmol/day. This excess sodium appears to be a major factor in hypertension (high blood pressure) in some people. Excretion of sodium is accomplished primarily by the kidneys. Sodium is freely filtered through the glomerular capillaries of the kidneys, and although much of the filtered sodium is reabsorbed in the proximal convoluted tubule, some remains in the filtrate and urine, and is normally excreted. Hyponatremia is a lower-than-normal concentration of sodium, usually associated with excess water accumulation in the body, which dilutes the sodium. An absolute loss of sodium may be due to a decreased intake of the ion coupled with its continual excretion in the urine. An abnormal loss of sodium from the body can result from several conditions, including excessive sweating, vomiting, or diarrhea; the use of diuretics; excessive production of urine, which can occur in diabetes; and acidosis, either metabolic acidosis or diabetic ketoacidosis. A relative decrease in blood sodium can occur because of an imbalance of sodium in one of the body’s other fluid compartments, like IF, or from a dilution of sodium due to water retention related to edema or congestive heart failure. At the cellular level, hyponatremia results in increased entry of water into cells by osmosis, because the concentration of solutes within the cell exceeds the concentration of solutes in the now-diluted ECF. The excess water causes swelling of the cells; the swelling of red blood cells—decreasing their oxygen-carrying efficiency and making them potentially too large to fit through capillaries—along with the swelling of neurons in the brain can result in brain damage or even death. Hypernatremia is an abnormal increase of blood sodium. It can result from water loss from the blood, resulting in the hemoconcentration of all blood constituents. Hormonal imbalances involving ADH and aldosterone may also result in higher-than-normal sodium values. |
What types of orbits do comets usually have? | spectral | vertical | convex | elliptical | Comets are small, icy objects that orbit the Sun in very elliptical orbits. When they are close to the Sun, they form comas and tails, which glow and make the comet more visible. |
What describes how close an estimate is to a known standard? | precision | diversity | frequency | accuracy | Accuracy describes how close an estimate is to a known standard. |
Canoe paddles, nutcracker, and hammer are examples of what type of simple machine? | pivot | lock | handle | lever | The canoe paddles, nutcracker, and hammer that you read about in this lesson have something in common. All three are examples of a type of simple machine called a lever. |
What do most species of monkeys have that no apes or humans do? | fur | five fingers | large brain | tail | What's the difference between monkeys and apes? The easiest way to distinguish monkeys from the other primates is to look for a tail. Most monkey species have tails, but no apes or humans do. Monkeys are much more like other mammals than apes and humans are. |
What are joints in which the bones are connected by a band of connective tissue? | plane | cartilaginous | saddle | syndesmoses | Syndesmoses are joints in which the bones are connected by a band of connective tissue, allowing for more movement than in a suture. An example of a syndesmosis is the joint of the tibia and fibula in the ankle. The amount of movement in these types of joints is determined by the length of the connective tissue fibers. Gomphoses occur between teeth and their sockets; the term refers to the way the tooth fits into the socket like a peg (Figure 38.24). The tooth is connected to the socket by a connective tissue referred to as the periodontal ligament. |
What are the four stages of food processing? | ingestion, reproduction, absorption, and elimination | ingestion, digestion, elimination and extinction | ingestion, digestion, absorption, and reproduction | ingestion, digestion, absorption, and elimination | 41.2 The main stages of food processing are ingestion, digestion, absorption, and elimination. |
What are different forms of the same gene? | nuerons | genomes | peptides | alleles | Homologous chromosomes form a pair, one from each parent. Homologous chromosomes are similar in size and shape, and contain the same genes, though they may have different alleles. Alleles are alternative forms of the same gene. This diagram represents two pairs of homologous chromosomes. |
What is the wheeled robot developed by nasa to explore the surface of mars? | mars SUV | mars robot | mars driver | mars rover | The Mars Rover pictured here is a wheeled robot developed by NASA. Its job is to explore the surface of Mars. The rover contains a lot of complex modern technology. But how it moves by rolling on wheels is a very old invention. The wheel was probably invented many times in different cultures, beginning at least 10,000 years ago. In addition to wheeled carts and chariots, early wheels were used for water wheels, grinding wheels, and wheels for spinning pottery. Wheels really changed human life. They revolutionized transportation and made it much easier to do many different kinds of work. |
What effect does taking anabolic steroids have on testosterone production? | increases it | does nothing | eliminates it | reduces it | Chapter 27 1 Sperm remain in the epididymis until they degenerate. 3 The fimbriae sweep the oocyte into the uterine tube. 5 The testes are located in the abdomen. 6 b 8 b 10 c 12 a 14 c 16 d 18 b 20 A single gamete must combine with a gamete from an individual of the opposite sex to produce a fertilized egg, which has a complete set of chromosomes and is the first cell of a new individual. 22 The three accessory glands make the following contributions to semen: the seminal vesicle contributes about 60 percent of the semen volume, with fluid that contains large amounts of fructose to power the movement of sperm; the prostate gland contributes substances critical to sperm maturation; and the bulbourethral glands contribute a thick fluid that lubricates the ends of the urethra and the vagina and helps to clean urine residues from the urethra. 24 Testosterone production by the body would be reduced if a male were taking anabolic steroids. This is because the hypothalamus responds to rising testosterone levels by reducing its secretion of GnRH, which would in turn reduce the anterior pituitary’s release of LH, finally reducing the manufacture of testosterone in the testes. 26 Meiosis in the man results in four viable haploid sperm, whereas meiosis in the woman results in a secondary oocyte and, upon completion following fertilization by a sperm, one viable haploid ovum with abundant cytoplasm and up to three polar bodies with little cytoplasm that are destined to die. 28 Endometrial tissue proliferating outside of the endometrium—for example, in the uterine tubes, on the ovaries, or within the pelvic cavity—could block the passage of sperm, ovulated oocytes, or a zygote, thus reducing fertility. 30 The internal reproductive structures form from one of two rudimentary duct systems in the embryo. Testosterone secretion stimulates growth of the male tract, the Wolffian duct. Secretions of sustentacular cells trigger a degradation of the female tract, the Müllerian duct. Without these stimuli, the Müllerian duct will develop and the Wolffian duct will degrade, resulting in a female embryo. |
Living in a large colony requires good communication. ants communicate with chemicals called what? | peptides | alkalides | hormones | pheromones | Living in a large colony requires good communication. Ants communicate with chemicals called pheromones . For example, an ant deposits pheromones on the ground as it returns to the nest from a food source. It is marking the path so other ants can find the food. Honeybees communicate by doing a “waggle dance. ”. |
What complex carbohydrates are the polymers of glucose? | fruits | sugars | fats | starches | Starches are complex carbohydrates that are polymers of glucose. Starches are used by plants to store energy. Consumers get starches by eating plants. They break down the starches to sugar for energy. |
What is the term for the shallow space above the zygomatic arch in a skull? | Medium Fossa | angular fossa | distinct fossa | temporal fossa | Figure 7.5 Lateral View of Skull The lateral skull shows the large rounded brain case, zygomatic arch, and the upper and lower jaws. The zygomatic arch is formed jointly by the zygomatic process of the temporal bone and the temporal process of the zygomatic bone. The shallow space above the zygomatic arch is the temporal fossa. The space inferior to the zygomatic arch and deep to the posterior mandible is the infratemporal fossa. |
What is the inner layer of skin called? | the epidermis | connective layer | hypodermis | the dermis | The dermis is the inner layer of skin. It is made of tough connective tissue. The dermis is attached to the epidermis by fibers made of the protein collagen. The dermis is where most skin structures are located. Look again at Figure above . You’ll see that the dermis has blood vessels and nerve endings. The nerve endings explain why skin can sense pain, pressure, and temperature. If you cut your skin and it bleeds, the cut has penetrated the dermis and damaged a blood vessel. The cut probably hurts as well because of the nerve endings in this skin layer. |
Many european and asiatic elms are less susceptible to dutch elm disease than which elms? | african | caribbean | rican | american | Accidentally introduced in the 1900s, the fungus decimated elm trees across the continent. Many European and Asiatic elms are less susceptible to Dutch elm disease than American elms. In humans, fungal infections are generally considered challenging to treat. Unlike bacteria, fungi do not respond to traditional antibiotic therapy, since they are eukaryotes. Fungal infections may prove deadly for individuals with compromised immune systems. Fungi have many commercial applications. The food industry uses yeasts in baking, brewing, and cheese and wine making. Many industrial compounds are byproducts of fungal fermentation. Fungi are the source of many commercial enzymes and antibiotics. |
What does a thermometer measure? | size | oxygen | precipitation | temperature | Temperature is the quantity measured by a thermometer. Temperature is related to the average kinetic energy of atoms and molecules in a system. Absolute zero is the temperature at which there is no molecular motion. There are three main temperature scales: Celsius, Fahrenheit, and Kelvin. Temperatures on one scale can be converted to temperatures on another scale using the following equations:. |
What are plant-like protists called? | spores | fungi | sponge | algae | Plant-like protists are called algae. They include single-celled diatoms and multicellular seaweed. |
What is a series of processes that remove unwanted substances from water called? | water cleaning | water filtration | water dilution | water treatment | Water treatment is a series of processes that remove unwanted substances from water. The goal of water treatment is to make the water safe to return to the natural environment or to the human water supply. Treating water for other purposes may not include all the same steps. That’s because water used in agriculture or industry may not have to be as clean as drinking water. |
Original atoms are called what type of isotopes? | product | offspring | component | parent | Direction is an important component of motion. |
What do you call an area covered with water, or possessing very soggy soil, all or part of the year? | island | stream | peninsula | wetland | Some of Earth’s freshwater is found in wetlands. A wetland is an area that is covered with water, or at least has very soggy soil, during all or part of the year. Certain species of plants thrive in wetlands, and they are rich ecosystems. Freshwater wetlands are usually found at the edges of streams, rivers, ponds, or lakes. Wetlands can also be found at the edges of seas. |
In which continent are meerkats most likely to be found? | Australia | North America | South America | africa | Another example of cooperation is seen with meerkats. Meerkats are small mammals that live in Africa. They also live in groups and cooperate with one another. For example, young female meerkats act as babysitters. They take care of the baby meerkats while their parents are away looking for food. |
What is the name of the thin layer that acts as a boundary between the stratosphere and the mesosphere? | spicule | spirogyra | ozone layer | stratopause | At the top of the stratosphere is a thin layer called the stratopause. It acts as a boundary between the stratosphere and the mesosphere. |
What is the process of removing wastes and excess water from the body? | ingestion | depletion | diffusion | excretion | Excretion is the process of removing wastes and excess water from the body. It is one of the major ways the body maintains homeostasis. Organs of excretion make up the excretory system. They include the kidneys, large intestine, liver, skin, and lungs. |
Which measure shows how individuals in a population are distributed, or spread throughout their area? | proportional distribution | geographical distribution | population phase | population distribution | Population density is an average measure. Often, individuals in a population are not spread out evenly. Instead, they may live in clumps or some other pattern. How individuals in a population are distributed, or spread throughout their area, is called population distribution. You can see different patterns of population distribution in Figure below . Different patterns characterize different species and types of environments, as you can read in the figure. |
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