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test · 389k rows

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What kind of enzyme is phosphofructokinase? Here are the choices: A. intracellular B. orthosteric C. allosteric D. covalent		C: allosteric.
Covering about 16 percent of the moon's surface, maria are dark, solid, flat areas consisting of what substance? Here are the choices: A. ash B. lava C. dust D. debris	When you look at the Moon from Earth, you notice dark and light areas. The maria are dark, solid, flat areas of lava. Maria covers around 16% of the Moon’s surface, mostly on the near side. The maria formed about 3.0 to 3.5 billion years ago, when the Moon was continually bombarded by meteorites ( Figure below ). Large...	B: lava.
Sickle cell disease is caused by production of an abnormal type of what? Here are the choices: A. leukocyte B. thrombocyte C. fat globule D. hemoglobin	down into three major groups: those caused by blood loss, those caused by faulty or decreased RBC production, and those caused by excessive destruction of RBCs. Clinicians often use two groupings in diagnosis: The kinetic approach focuses on evaluating the production, destruction, and removal of RBCs, whereas the morph...	D: hemoglobin.
Who first proposed that earth is a magnet? Here are the choices: A. william gilbert B. Isaac Newton C. Albert Einstein D. Marconi	The molar mass of any substance is the mass in grams of one mole of representative particles of that substance. The representative particles can be atoms, molecules, or formula units of ionic compounds. This relationship is frequently used in the laboratory. Suppose that for a certain experiment you need 3.00 moles of ...	A: william gilbert.
Which atomic model shows that the distances of electrons from the nucleus is not a fixed value? Here are the choices: A. the electron model B. the quantum model C. the distance model D. the equivocation model	In the Bohr model, the atom is viewed as a densely packed nucleus comprised of neutrons and protons that is surrounded by electrons at fixed distances, which correspond to specific energy levels. However, the quantum model showed that the distances between electrons and the nucleus are not really fixed. Due to their wa...	B: the quantum model.
What is it called when breaks in bone occur that is usually caused by excessive stress on the bone? Here are the choices: A. fragments B. faults C. ruptures D. fractures	Fractures are breaks in bone, usually caused by excessive stress on bone. Fractures heal when osteoblasts form new bone. The animation at this link shows how this happens: http://www. youtube. com/watch?v=qVougiCEgH8 . Soon after a fracture, the body begins to repair the break. The area becomes swollen and sore. Within...	D: fractures.
What crystals consist of molecules at the lattice points of the crystal, held together by relatively weak intermolecular forces? Here are the choices: A. salt crystals B. healing crystals C. molecular crystals D. quartz crystals	4. Molecular crystals -- Molecular crystals typically consist of molecules at the lattice points of the crystal, held together by relatively weak intermolecular forces (see Figure below ). The intermolecular forces may be dispersion forces in the case of nonpolar crystals, or dipole-dipole forces in the case of polar c...	C: molecular crystals.
What causes continents to drift closer to the poles or the equator? Here are the choices: A. time B. plate tectonics C. earthquakes D. plate movements	Plate movements cause continents to drift closer to the poles or the equator. Ocean currents also shift when continents drift. All these changes can affect Earth’s temperature.	D: plate movements.
What is the major selective advantage of myelination? Here are the choices: A. storage capacity B. heat regulation C. potentiation D. space efficiency		D: space efficiency.
What debated therapy offers a potential method for replacing neurons lost to injury or disease? Here are the choices: A. cell duplication B. stem cell reduction C. cell production therapy D. stem cell therapy		D: stem cell therapy.
How many types of simple machines are there? Here are the choices: A. six types B. three types C. two types D. ten types	There are six types of simple machines. Machines that consist of two or more simple machines are called compound machines.	A: six types.
After dispersal of a seed, what next step may occur if environmental conditions are favorable? Here are the choices: A. infection B. bloom C. degradation D. germination		D: germination.
What is the term for the smallest particle of an element that still has the properties of that element? Here are the choices: A. atom B. electron C. nucleus D. neutron	An element is a pure substance. It cannot be broken down into other types of substances. Each element is made up of just one type of atom. An atom is the smallest particle of an element that still has the properties of that element.	A: atom.
What are insect parasites transmitted sexually? Here are the choices: A. pinworms B. chlamydia C. pubic lice D. deer ticks	Pubic lice , like the one in Figure below , are insect parasites that are transmitted sexually. They suck the blood of their host and irritate the skin in the pubic area.	C: pubic lice.
What type of energy is used when a roller coaster runs downhill? Here are the choices: A. residual energy B. vibrational energy C. kinetic energy D. proportional energy	For some, the exciting part of a roller coaster is speeding down; for others it is the anticipation of climbing up. While the coaster is being towed up, it is having work done on it. The work done towing it to the top of the hill becomes potential energy stored in the coaster and that potential energy is converted to k...	C: kinetic energy.
In what process is atp created by glycolysis, without oxygen? Here are the choices: A. sedimentation B. oxidation C. condensation D. fermentation	Two different pathways accomplish the regeneration of NAD + with rather famous products: lactic acid (C 3 H 6 O 3 ) and ethyl alcohol (C 2 H 6 O) ( Figure above ). Making ATP in the absence of oxygen by glycolysis alone is known as fermentation . Therefore, these two pathways are called lactic acid fermentation and alc...	D: fermentation.
What helps deposit the material in caves as stalactites, stalagmites, and columns Here are the choices: A. groundwater B. gas C. precipitation D. wastewater	Groundwater deposits the material in caves as stalactites, stalagmites, and columns.	A: groundwater.
A recent deadly explosion in the gulf of mexico exemplified what source of ocean pollution? Here are the choices: A. fracking disaster B. greenhouse gases C. oil spill D. algal bloom	Oil spills are another source of ocean pollution. To get at oil buried beneath the seafloor, oil rigs are built in the oceans. These rigs pump oil from beneath the ocean floor. Huge ocean tankers carry oil around the world. If something goes wrong with a rig on a tanker, millions of barrels of oil may end up in the wat...	C: oil spill.
Plants supply, ultimately, most of the food eaten by terrestrial animals, along with what gas? Here are the choices: A. carbon dioxide B. nitrogen C. hydrogen D. oxygen		D: oxygen.
Chemical reactions are typically written to imply that they proceed in one direction - if they can occur in either direction, they are considered what? Here are the choices: A. observable B. reactive C. singular D. reversible	A chemical reaction is usually written in a way that suggests it proceeds in one direction, the direction in which we read, but all chemical reactions are reversible, and both the forward and reverse reaction occur to one degree or another depending on conditions. In a chemical equilibrium, the forward and reverse reac...	D: reversible.
Single-celled eukaryotes that share some traits with animals are also called? Here are the choices: A. prokaryotes B. monomers C. microorganisms D. eukaryotes	Protozoa are single-celled eukaryotes that share some traits with animals.	D: eukaryotes.
Antibiotics can be used to fight what, in general? Here are the choices: A. bacteria B. pathogens C. viruses D. fever	In summary, society is facing an antibiotic crisis. Some scientists believe that after years of being protected from bacterial infections by antibiotics, we may be returning to a time in which a simple bacterial infection could again devastate the human population. Researchers are working on developing new antibiotics,...	A: bacteria.
An organism that carries pathogens from one individual to another is called what? Here are the choices: A. virus B. host C. germ cell D. vector	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 or mosquitoes. They pick up pathogens when they bite an infected animal and then transmit the pathogens to the next animal they bite. Ticks spread the ...	D: vector.
What fills the epidermal cells that make up fingernails and toenails? Here are the choices: A. amino acids B. cellulose C. keratin D. chromatin	Fingernails and toenails consist of specialized epidermal cells that are filled with keratin . The keratin makes them tough and hard, which is important for the functions they serve. Fingernails prevent injury by forming protective plates over the ends of the fingers. They also enhance sensation by acting as a counterf...	C: keratin.
What is the name for a parasite that causes disease? Here are the choices: A. pathogen B. fungi C. enfluenza D. microbes		A: pathogen.
What type of map shows the elevation and features in an area? Here are the choices: A. topographic B. gradient C. meteorological D. geographic	Relief , or terrain, includes all the landforms of a region. A topographic map shows the height, or elevation , of features in an area. This includes mountains, craters, valleys, and rivers. For example, Figure below shows the San Francisco Peaks in northern Arizona. Features on the map include mountains, hills and lav...	A: topographic.
What are organelles made of protein and ribosomal rna (rrna)? Here are the choices: A. electrons B. carbons C. chromosomes D. ribosomes	The nucleus of many cells also contains a non-membrane bound organelle called a nucleolus , shown in Figure below . The nucleolus is mainly involved in the assembly of ribosomes. Ribosomes are organelles made of protein and ribosomal RNA (rRNA), and they build cellular proteins in the cytoplasm. The function of the rRN...	D: ribosomes.
What are major temperature zones primarily based on? Here are the choices: A. longitude B. latitute C. gps D. altitude	Temperature falls from the equator to the poles. Therefore, major temperature zones are based on latitude . They include tropical, temperate, and arctic zones (see Figure below ). However, other factors besides latitude may also influence temperature. For example, land near the ocean may have cooler summers and warmer ...	B: latitute.
What type of muscle is found in the walls of other internal organs such as the stomach? Here are the choices: A. inorganic muscle B. smooth muscle C. Fiber Muscle D. Tube Muscle	Smooth muscle is found in the walls of other internal organs such as the stomach. It isn’t striated because its muscle fibers are arranged in sheets rather than bundles. Contractions of smooth muscle are involuntary. When smooth muscles in the stomach contract, they squeeze food inside the stomach. This helps break the...	B: smooth muscle.
A visual "copy" of an object that is formed by reflected or refracted light is called what? Here are the choices: A. mirror B. image C. instance D. photo	Almost all surfaces reflect some of the light that strikes them. The still water of the lake in Figure above reflects almost all of the light that strikes it. The reflected light forms an image of nearby objects. An image is a copy of an object that is formed by reflected or refracted light.	B: image.
From the pharynx, air next passes through what structure, also known as the voice box because it contains vocal cords? Here are the choices: A. larynx B. diaphram C. trachea D. pancreas	From the pharynx, air next passes through the larynx , or voice box. The larynx contains vocal cords, which allow us to produce vocal sounds.	A: larynx.
Vertebrates are all chordates that have a what? Here are the choices: A. backbone B. brain C. circulatory system D. fossil	Living species of chordates are classified into three major subphyla: Vertebrata, Urochordata, and Cephalochordata. Vertebrates are all chordates that have a backbone. The other two subphyla are invertebrate chordates that lack a backbone. Members of the subphylum Urochordata are tunicates (also called sea squirts). Me...	A: backbone.
What do structures of the human eye collect and focus? Here are the choices: A. light B. air C. electricity D. sugars	The structures of the human eye collect and focus light. They form a reduced, upside-down image on the retina at the back of the eye.	A: light.
Different elements differ in the size, mass, and other properties of what fundamental structures? Here are the choices: A. atoms B. particles C. compounds D. ions	Atoms of different elements differ in size, mass, and other properties.	A: atoms.
Breasts are considered accessory organs of what body system? Here are the choices: A. female reproductive system B. nervous system C. lymphatic system D. digestive system	The Breasts Whereas the breasts are located far from the other female reproductive organs, they are considered accessory organs of the female reproductive system. The function of the breasts is to supply milk to an infant in a process called lactation. The external features of the breast include a nipple surrounded by ...	A: female reproductive system.
Because plants lack what kind of system, their first line of defense is usually the death of cells surrounding infected tissue to prevent spread of infection? Here are the choices: A. digestion system B. immune system C. nervous system D. hormones system	Plants don't have an immune system, but they do respond to disease. Typically, their first line of defense is the death of cells surrounding infected tissue. This prevents the infection from spreading.	B: immune system.
What type of cells make up tumors? Here are the choices: A. cancer cells B. boyle cells C. consumption cells D. white blood cells		A: cancer cells.
When leaves wilt, what plant process ceases? Here are the choices: A. photosynthesis B. carbonation C. hydration D. reactions	Photosynthesis ceases when leaves wilt, mainly because.	A: photosynthesis.
What type of tissue makes up much of the inside of a plant? Here are the choices: A. leaf tissue B. working tissue C. ground tissue D. stem tissue	Ground tissue makes up much of the inside of a plant. The cells of ground tissue carry out basic metabolic functions and other biochemical reactions. Ground tissue may also store food or water.	C: ground tissue.
Saliva can carry the hiv virus, but it won't spread it, unless the saliva gets into what? Here are the choices: A. liver B. lungs C. bloodstream D. kidneys	HIV spreads through contact between an infected person’s body fluids and another person's bloodstream or mucus membranes, which are found in the mouth, nose, and genital areas. Body fluids that may contain HIV are blood, semen, vaginal fluid, and breast milk. The virus can spread through sexual contact or shared drug n...	C: bloodstream.
Does blood flow increase or decrease when blood vessels constrict? Here are the choices: A. decrease B. it's not affected C. increases D. it stops	When a blood vessel constricts, less blood can flow through it.	A: decrease.
What is venus covered in a thick layer of? Here are the choices: A. fog B. clouds C. gases D. storms	Viewed through a telescope, Venus looks smooth and featureless. The planet is covered by a thick layer of clouds. You can see the clouds in pictures of Venus ( Figure below ).	B: clouds.
What type of aquifer is trapped between two impermeable rock layers? Here are the choices: A. confined B. solid C. abandoned D. segmented	Sometimes an aquifer is confined. A confined aquifer is trapped between two impermeable rock layers. Pressure from the rock layer on top forces the water out where the aquifer reaches the ground surface. Water that flows up to the surface naturally is an artesian spring . If people drill a well into a confined aquifer,...	A: confined.
Name the multi-phase process in which the nucleus of a eukaryotic cell divides? Here are the choices: A. mitosis B. symbiosis C. cytokinesis D. meiosis	Mitosis in the Eukaryotic Cell Cycle. Mitosis is the multi-phase process in which the nucleus of a eukaryotic cell divides. In this diagram, prometaphase is not included as a separate phase, but incorporated into prophase.	A: mitosis.
What is the term for the basic contractile unit of the muscle? Here are the choices: A. filament B. sphincter C. bandimere D. sarcomere		D: sarcomere.
What are chemical messengers that control sexual development and reproduction? Here are the choices: A. neurotransmitters B. proteins C. sex hormones D. lipids	Sex hormones are chemical messengers that control sexual development and reproduction. The male reproductive system consists of structures that produce male gametes called sperm and secrete the male sex hormone testosterone.	C: sex hormones.
What are species that are first to colonize a disturbed area called? Here are the choices: A. novel species B. brave species C. exploratory species D. pioneer species	The first species to colonize a disturbed area such as this are called pioneer species (see Figure below ). They change the environment and pave the way for other species to come into the area. Pioneer species are likely to include bacteria and lichens that can live on bare rock. Along with wind and water, they help we...	D: pioneer species.
What planet is the easiest to observe? Here are the choices: A. mercury B. mars C. uranus D. pluto	Mars is the easiest planet to observe. As a result, it has been studied more than any other planet besides Earth. People can stand on Earth and observe the planet through a telescope. We have also sent many space probes to Mars. A car-sized robotic rover, Curiosity, arrived on the Red Planet in August 2012. Curiosity j...	B: mars.
Where does the heartbeat originate in vertebrates? Here are the choices: A. the blood B. the heart C. the tissue D. the pulse		B: the heart.
What is a process where some substances called reactants change chemically into different substances called products? Here are the choices: A. carbon reaction B. crystals reaction C. chemical reaction D. non-chemical reaction	The student athlete in Figure below is practically flying down the track! Running takes a lot of energy. But you don’t have to run a race to use energy. All living things need energy all the time just to stay alive. The energy is produced in chemical reactions. A chemical reaction is a process in which some substances,...	C: chemical reaction.
Cellulose is the main structural component of what part of the plant cell, and makes up over thirty percent of plant matter? Here are the choices: A. flowers B. cell wall C. roots D. proteins wall	Figure 31.3 Cellulose, the main structural component of the plant cell wall, makes up over thirty percent of plant matter. It is the most abundant organic compound on earth. Plants are able to make their own cellulose, but need carbon from the soil to do so.	B: cell wall.
What is a push or a pull acting on an object? Here are the choices: A. energy B. action C. pulse D. force	Force is a push or a pull acting on an object. Examples of force include friction and gravity. Force is a vector because it has both size and direction. The SI unit of force is the newton (N).	D: force.
Which organ will bladder infections commonly damage if untreated? Here are the choices: A. lungs B. tissue C. heart D. kidney	Bacterial infections of the urinary tract, especially the bladder, are very common. Bladder infections can be treated with antibiotics prescribed by a doctor. If untreated, they may lead to kidney damage.	D: kidney.
What is the acid that is released by the stomach that kills most pathogens that enter the stomach? Here are the choices: A. Nitric Acid B. Sulfuric Acid C. Hydrofluoric Acid D. hydrochloric acid	The stomach also releases a very strong acid, called hydrochloric acid. This acid kills most pathogens that enter the stomach in food or water. Urine is also acidic, so few pathogens can grow in it.	D: hydrochloric acid.
What occurs when force is applied to a moving object? Here are the choices: A. inertia B. acceleration C. stimulation D. transmission	Acceleration occurs when a force is applied to a moving object.	B: acceleration.
Smooth, cardiac, and skeletal are all types of what? Here are the choices: A. teeth B. muscle C. hormones D. bone	The three types of muscles in the body include skeletal muscle, smooth muscle, and cardiac muscle.	B: muscle.
What group of elements does sodium belong to? Here are the choices: A. metalloids B. alkali metals C. noble gases D. halogens	Sodium belongs to the group of elements called the alkali metals. An alkaline solution is another name for a solution that is basic. All alkali metals react readily with water to produce the metal hydroxide and hydrogen gas. The resulting solutions are basic.	B: alkali metals.
Pure constructive interference and pure destructive interference are distinguished by whether or not identical waves are what? Here are the choices: A. after phase B. in equilibrium C. in phase D. before phase	Figure 27.11 The amplitudes of waves add. (a) Pure constructive interference is obtained when identical waves are in phase. (b) Pure destructive interference occurs when identical waves are exactly out of phase, or shifted by half a wavelength.	C: in phase.
The process of photosynthesis uses chlorophyll, which is located in organelles called what? Here are the choices: A. fibroblasts B. nucleus C. mitochondria D. chloroplasts	Plants are a large and varied group of organisms. There are close to 300,000 species of catalogued plants. Of these, about 260,000 are plants that produce seeds. Mosses, ferns, conifers, and flowering plants are all members of the plant kingdom. The plant kingdom contains mostly photosynthetic organisms; a few parasiti...	D: chloroplasts.
What kind of oily substance is secreted from sebaceous glands? Here are the choices: A. pus B. progesterone C. sebum D. Blood	Sebaceous glands produce an oily substance called sebum. Sebum is secreted into hair follicles and makes its way to the skin surface. It waterproofs the hair and skin and helps prevent them from drying out. Sebum also has antibacterial properties, so it inhibits the growth of microorganisms on the skin.	C: sebum.
Some reactions need extra help to occur quickly. they need another substance called what? Here are the choices: A. protein B. a catalyst C. neurotransmitter D. hormone	Some reactions need extra help to occur quickly. They need another substance called a catalyst. A catalyst is a substance that increases the rate of a chemical reaction. A catalyst isn’t a reactant, so it isn’t changed or used up in the reaction. Therefore, it can catalyze many other reactions.	B: a catalyst.
What have approximately the same mass as protons but no charge? Here are the choices: A. neutrons B. atoms C. electrons D. reactions	Neutrons have approximately the same mass as protons but no charge. They are electrically neutral. The mass of a proton or a neutron is about 1836 times greater than the mass of an electron. Protons and neutrons constitute by far the bulk of the mass of atoms. The discovery of the electron and the proton was crucial to...	A: neutrons.
Amniocentesis and chorionic villus sampling can indicate whether a suspected genetic disorder is present at what stage? Here are the choices: A. toddler B. fetal C. adult D. infant		B: fetal.
What do you call aquatic biomes in the ocean? Here are the choices: A. ocean dwellers B. coastal biomes C. freshwater biomes D. marine biomes	Anglerfish live in the ocean. Aquatic biomes in the ocean are called marine biomes . Organisms that live in marine biomes must be adapted to the salt in the water. For example, many have organs for excreting excess salt. Two ocean zones are particularly challenging to marine organisms: the intertidal zone and the deep ...	D: marine biomes.
The reaction of which body system causes food allergies? Here are the choices: A. cardiac system B. lymphatic system C. immune system D. nervous system	Food allergies are like other allergies. They occur when the immune system reacts to harmless substances as though they were harmful. Almost ten percent of children have food allergies. Some of the foods most likely to cause allergies are shown below ( Figure below ).	C: immune system.
Leaving tampons in for too long can put you at risk of what syndrome? Here are the choices: A. Endometrial Cancer B. Vaginismis C. toxic shock D. Scalded Skin Syndrome	If you are a girl and use tampons, be sure to change them every four to six hours. Leaving tampons in for too long can put you at risk of toxic shock syndrome . This is a serious condition. Signs and symptoms of toxic shock syndrome develop suddenly, and the disease can be fatal. The disease involves fever, shock, and ...	C: toxic shock.
There are three flat skeletal muscles in the antero-lateral wall of what? Here are the choices: A. thoracic cavity B. abdomen C. hip joint D. shoulder socket	There are three flat skeletal muscles in the antero-lateral wall of the abdomen. The external oblique, closest to the surface, extend inferiorly and medially, in the direction of sliding one’s four fingers into pants pockets. Perpendicular to it is the intermediate internal oblique, extending superiorly and medially, t...	B: abdomen.
The dead, dry stratum corneum is the most superficial layer of what and is the layer exposed to the outside environment? Here are the choices: A. lungs B. epidermis C. intestinal D. dermis	Stratum Corneum The stratum corneum is the most superficial layer of the epidermis and is the layer exposed to the outside environment (see Figure 5.5). The increased keratinization (also called cornification) of the cells in this layer gives it its name. There are usually 15 to 30 layers of cells in the stratum corneu...	B: epidermis.
What protein is produced when a plasma cell is stimulated by antigens? Here are the choices: A. collagen B. keratin C. immunoglobulin D. dystrophin	42.3 \| Antibodies By the end of this section, you will be able to: • Explain cross-reactivity • Describe the structure and function of antibodies • Discuss antibody production An antibody, also known as an immunoglobulin (Ig), is a protein that is produced by plasma cells after stimulation by an antigen. Antibodies are...	C: immunoglobulin.
An unbalanced force on an object in motion causes what? Here are the choices: A. agitation B. vibration C. velocity D. acceleration	An object will not change its state of motion (i. e. , accelerate) unless an unbalanced force acts on it. Equal and oppositely directed forces on the same object do not produce acceleration.	D: acceleration.
Partial albinism results from a mutation in an enzyme that is involved in the production of what? Here are the choices: A. melanin B. hair C. cytoplasm D. cancer	The pointed pattern is a form of partial albinism, which results from a mutation in an enzyme that is involved in melanin production. The mutated enzyme is heat-sensitive; it fails to work at normal body temperatures. However, it is active in cooler areas of the skin. This results in dark coloration in the coolest part...	A: melanin.
Where does a baby travel to after leaving the uterus? Here are the choices: A. nasal canal B. birth canal C. ear canal D. tissue canal	Some processes in the body are regulated by positive feedback. Positive feedback is when a response to an event increases the likelihood of the event to continue. An example of positive feedback is milk production in nursing mothers. As the baby drinks her mother's milk, the hormone prolactin, a chemical signal, is rel...	B: birth canal.
Name an important natural resource in and of itself. Here are the choices: A. habitat B. biodiversity C. food chain D. water	It’s obvious that living things are important natural resources needed by human beings. After all, other species provide us with all of the food we eat. We couldn’t survive without them. But that’s far from the only reason that other species are important for human survival. Biodiversity is an important natural resourc...	B: biodiversity.
In classical conditioning, a response called the conditioned response is associated with what? Here are the choices: A. conditioned stimulus B. unconditioned stimulus C. external inhibition D. blocking effect	Conditioned Behavior Conditioned behaviors are types of associative learning, where a stimulus becomes associated with a consequence. During operant conditioning, the behavioral response is modified by its consequences, with regards to its form, strength, or frequency. Classical Conditioning In classical conditioning, ...	A: conditioned stimulus.
What kind of bonds does boron form rather than metallic lattices? Here are the choices: A. multicenter B. electron bonds C. magnetic bonds D. bilateral	Boron forms multicenter bonds rather than metallic lattices with delocalized valence electrons. Why does it prefer this type of bonding? Does this explain why boron behaves like a semiconductor rather than a metal? Explain your answer.	A: multicenter.
What broad group of living things serves as the major producers in terrestrial biomes? Here are the choices: A. animals B. vases C. flowers D. plants	Plants are the major producers in terrestrial biomes. They have five basic needs: air, warmth, sunlight, water, and nutrients. How well these needs are met in a given location depends on the growing season and soil quality, both of which are determined mainly by climate.	D: plants.
Birds that move pollen from flower to flower are called what? Here are the choices: A. carnivores B. pollinators C. frogs D. spores	Nectar-feeding birds are important pollinators , meaning they move the pollen from flower to flower to help fertilize the sex cells and create new plants. Hummingbirds, sunbirds, and the honey-eaters are common pollinators.	B: pollinators.
The major cause of outdoor air pollution is the burning of? Here are the choices: A. fossil fuels B. trees C. charcoal briquettes D. trash	The major cause of outdoor air pollution is the burning of fossil fuels.	A: fossil fuels.
What is the ideal mechanical advantage in the single fixed pulley? Here are the choices: A. 1 B. 4 C. 2 D. zero	In the single fixed pulley, only one rope segment pulls up on the load, so the ideal mechanical advantage is 1. In other words, this type of pulley doesn’t increase the force that is applied to it. However, it does change the direction of the force. This allows you to use your weight to pull on one end of the rope and ...	A: 1.
What science is the study of matter and the changes it undergoes? Here are the choices: A. chemistry B. astronomy C. geology D. biology	Chemistry is the study of matter and the changes it undergoes.	A: chemistry.
What is driven by the sun's energy and moves water over the surface of earth? Here are the choices: A. the water cycle B. sun cycle C. tides D. weather cycle	The Sun heats some areas more than others, which causes wind. The Sun's energy also drives the water cycle, which moves water over the surface of the Earth. Both wind and water power can be used as renewable resources.	A: the water cycle.
What are materials that are poor thermal conductors called? Here are the choices: A. sunlight insulators B. thermal insulators C. warmth insulators D. pollution insulators	Particles of gases are farther apart and have fewer collisions, so they are not good at transferring thermal energy. Materials that are poor thermal conductors are called thermal insulators . Figure below shows several examples. Fluffy yellow insulation inside the roof of a home is full of air. The air prevents the tra...	B: thermal insulators.
Balanced chemical reactions are balanced in what? Here are the choices: A. terms of moles B. electrical charge C. molecular bonds D. atoms	Balanced chemical reactions are balanced in terms of moles.	A: terms of moles.
The autonomic nervous system serves as the relay between what and the internal organs? Here are the choices: A. somatic system B. central nervous system C. hormones D. peripheral nervous system	The autonomic nervous system serves as the relay between the CNS and the internal organs. It controls the lungs, the heart, smooth muscle, and exocrine and endocrine glands. The autonomic nervous system controls these organs largely without conscious control; it can continuously monitor the conditions of these differen...	B: central nervous system.
The role that a particular species plays in its ecosystem is also known as what? Here are the choices: A. unique B. niche C. market D. type	Niche is the role that a particular species plays in its ecosystem. This role includes all the ways that the species interacts with the biotic and abiotic factors in the ecosystem.	B: niche.
What element has the atomic number 16? Here are the choices: A. sulfur B. neon C. oxygen D. helium		A: sulfur.
Name the most famous satellite of the earth? Here are the choices: A. the moon B. sputnik C. demos D. skylab		A: the moon.
What is the minimum number of loops a circuit can have? Here are the choices: A. 3 B. 2 C. 1 D. .1	An electric circuit consists of at least one closed loop through which electric current can flow. Every circuit has a voltage source such as a battery and a conductor such as metal wire. A circuit may have other parts as well, such as lights and switches. In addition, a circuit may consist of one loop or two loops.	C: 1.
What type of organism is algae? Here are the choices: A. virus B. bacteria (cyanobacteria) C. yeast D. amoeba	Describe why algae is a good source of biofuel.	B: bacteria (cyanobacteria).
When water slows down, it starts depositing sediment, starting with which particles first? Here are the choices: A. lightest B. largest C. finest D. smallest	How water transports particles depends on their size. When water slows down, it starts depositing sediment, starting with the largest particles first.	B: largest.
Because they control many cell activities - as well as being controlled by feedback mechanisms - what substances are very important for homeostasis? Here are the choices: A. hormones B. enzymes C. proteins D. acids	Hormones control many cell activities, so they are very important for homeostasis. But what controls the hormones themselves? Most hormones are regulated by feedback mechanisms. A feedback mechanism is a loop in which a product feeds back to control its own production. Most hormone feedback mechanisms involve negative ...	A: hormones.
Contraction of what large, sheet-like muscle results in inhalation? Here are the choices: A. uterus B. diaphragm C. pelvic floor D. deltoid	Inhaling is an active movement that results from the contraction of a muscle called the diaphragm. The diaphragm is large, sheet-like muscle below the lungs (see Figure below ). When the diaphragm contracts, the ribcage expands and the contents of the abdomen move downward. This results in a larger chest volume, which ...	B: diaphragm.
What type of ionic compound is formed from acid and bases reacting with each other? Here are the choices: A. salt B. dry C. isolated D. common	Acids have some properties in common. They turn litmus, a plant extract, red. They react with some metals to give off H2 gas. They react with carbonate and hydrogen carbonate salts to give off CO2 gas. Acids that are ingested typically have a sour, sharp taste. (The name acid comes from the Latin word acidus, meaning “...	A: salt.
The iron ion used to bind oxygen is on what type of "ring"? Here are the choices: A. reagent ring B. petrarchan ring C. porphyrin ring D. DNA ring	The yellow subunits are identical in structure, as are the gray subunits. A smaller organic structure called a porphyrin ring is attached to each protein subunit and contains the iron ion used to bind oxygen.	C: porphyrin ring.
In police radar, a radar gun sends out short bursts of which waves? Here are the choices: A. microwaves B. photons C. soundwaves D. electrodes	Radar stands for ra dio d etection and r anging. In police radar, a radar gun sends out short bursts of microwaves. The microwaves reflect back from oncoming vehicles and are detected by a receiver in the radar gun. The frequency of the reflected waves is used to compute the speed of the vehicles. Radar is also used fo...	A: microwaves.
Oxides of small, highly charged ions of what type tend to be acidic? Here are the choices: A. plastic B. metal C. steel D. liquid	Summary The transition metals are characterized by partially filled d subshells in the free elements and cations. The ns and (n − 1)d subshells have similar energies, so small influences can produce electron configurations that do not conform to the general order in which the subshells are filled. In the secondand thir...	B: metal.
A lewis acid is a substance that accepts a pair of electrons to form what? Here are the choices: A. covalent bond B. functionality bond C. accretion bond D. ambivalent bond	Gilbert Lewis (1875-1946) proposed a third theory of acids and bases that is even more general than either the Arrhenius or Brønsted-Lowry theories. A Lewis acid is a substance that accepts a pair of electrons to form a covalent bond. A Lewis base is a substance that donates a pair of electrons to form a covalent bond....	A: covalent bond.
What is the amount of force pushing against a given area? Here are the choices: A. energy B. pressure C. inertia D. power	Pressure is defined as the amount of force pushing against a given area. How much pressure a gas exerts depends on the amount of gas. The more gas particles there are, the greater the pressure.	B: pressure.
What is another word for seed plants? Here are the choices: A. echinoderm B. phyla C. protosperm D. gymnosperm	The most basic division is between nonvascular plants and vascular plants . Vascular plants are further divided into those that reproduce without seeds and those that reproduce with seeds. Seed plants, in turn, are divided into those that produce seeds in cones and those that produce seeds in the ovaries of flowers. Se...	D: gymnosperm.
What process takes place when echinoderms release their gametes into the water? Here are the choices: A. fertilization B. stimulation C. migration D. isolation	The echinoderm nervous system has a nerve ring at the center and five radial nerves extending outward along the arms. There is no centralized nervous control. Echinoderms have separate sexes and release their gametes into the water where fertilization takes place. Echinoderms may also reproduce asexually through regene...	A: fertilization.

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