Biology Test 3

The fauna and flora of Australia are very different from those of the rest of the world. Why might this be true? A. Australia has been isolated for about 50 million years. B. Life in Australia was wiped out by ancient volcanic eruptions. C. The climate of Australia is unlike that of any other place in the world. D. Australia was never in close proximity to the other continents. E. They have become different by convergent evolution.

A. Australia has been isolated for about 50 million years.

_____________________ are triggered when stimuli become too extreme for thermoreceptors. A. Pain receptors B. Chemoreceptors C. Mechanoreceptors D. Electromagnetic receptors

A. Pain receptors

Which of the following events is the direct result of an action potential in the membrane of a muscle cell? A. The muscle cell's endoplasmic reticulum (ER) releases calcium ions. B. Calcium ions are pumped into the endoplasmic reticulum (ER). C. The myosin head detaches from actin. D. The myosin head extends. E. The muscle relaxes.

A. The muscle cell's endoplasmic reticulum (ER) releases calcium ions.

Digestion is ______. A. breakdown of food into small nutrient molecules that the body can absorb B. eating C. churning of food in the stomach and intestine D. the absorption of nutrients

A. breakdown of food into small nutrient molecules that the body can absorb

Higher brain functions, such as creativity and analytical skills, are centered in the _____. A. cerebrum B. cerebellum C. hypothalamus D. corpus callosum

A. cerebrum

The cerebrum develops from the _______________ A. forebrain B. midbrain C. hindbrain D. brain stem

A. forebrain

What acid is responsible for stomach acidity? A. hydrochloric acid B. carbonic acid C. sulfuric acid D. acetic acid E. sodium hydroxide

A. hydrochloric acid

Most homeostatic mechanisms depend on ______. A. negative feedback B. predictable internal conditions C. predictable environmental conditions D. positive and negative feedback

A. negative feedback

Most mechanical processing of food occurs in the _____. A. oral cavity and stomach B. oral cavity and small intestine C. small intestine and large intestine D. stomach and small intestine

A. oral cavity and stomach

Goldfish and guppies are in the same class. Therefore, they must also be members of the same _____. A. phylum B. family C. genus D. order E. species

A. phylum

Water held behind a dam is similar to what aspect of a neuron? A. resting potential B. threshold C. dendrites D. action potential

A. resting potential

A neuron can relay a more intense signal by ______. A. sending more action potentials in a given amount of time B. sending an action potential that travels more quickly C. sending a stronger action potential D. sending a longer action potential

A. sending more action potentials in a given amount of time

Which of the following neurons are part of the peripheral nervous system? A. sensory neuron and motor neuron B. interneuron neuron and motor neuron C. interneuron neuron and sensory neuron D. only motor neurons

A. sensory neuron and motor neuron

The space between an axon of one neuron and the dendrite of another neuron is called a(n) _____. A. synaptic cleft B. node of Ranvier C. internodes D. synapse E. synaptic terminal

A. synaptic cleft

During an action potential A. the inside of the neuron becomes positively charged relative to the outside. B. potassium ions move into the neuron. C. sodium ions move into the neuron, then potassium ions move in. D. the inside of the neuron becomes negatively charged relative to the outside. E. potassium channels open first, followed by sodium channels.

A. the inside of the neuron becomes positively charged relative to the outside.

A biologist spends her summer break collecting frogs from a remote jungle in Peru. She discovers two distinct color forms that could be variants of a single species or two different species. What would be the most direct test of their species status under the biological species concept? A. Compare the color patterns of the two groups. If they are distinct enough, the two forms belong to different species. B. Observe mating in the natural environment of the two groups. If the two forms do not mate with each other, they are different species. C. Compare the DNA of the two groups. If their genes are different, they must be different species. D. Compare the habitat use of the two groups. If they use different habitats, they must be different species.

B. Observe mating in the natural environment of the two groups. If the two forms do not mate with each other, they are different species.

Which of the following best illustrates homeostasis? A. Cells of the skin are constantly worn off and replaced. B. When blood CO2 increases, you breathe faster and get rid of CO2. C. All the cells in the body have much the same chemical composition. D. The lung has a large surface for exchange of gases. E. All organs are composed of the same four types of tissue.

B. When blood CO2 increases, you breathe faster and get rid of CO2.

The movement of an action potential along a neuron is most like ______. A. a radio tower emitting a signal that reaches only a small region B. a crowd at a sporting event doing the wave around a stadium C. the ripples created by dropping a pebble into a pond, gradually decreasing in size as the waves spread apart D. the sound of your voice spreading out as you yell loudly to your friend while at a park

B. a crowd at a sporting event doing the wave around a stadium

An action potential moves along a(n) _____. A. myelin sheath B. axon C. dendrite D. synapse E. cell body

B. axon

Calcium ions A. are released by the motor neuron. B. bind to the protein that blocks the myosin-binding sites on actin. C. are pumped into the endoplasmic reticulum (ER) during an action potential. D. bind to actin. E. bind to ATP.

B. bind to the protein that blocks the myosin-binding sites on actin.

The pleasant scent of roses is detected by ____________. A. thermoreceptors B. chemoreceptors C. mechanoreceptors D. electromagnetic receptors

B. chemoreceptors

Different species that occupy similar niches in isolated areas develop morphological similarities. This phenomenon is called _____. A. symbiosis B. convergent evolution C. adaptive radiation D. the founder effect

B. convergent evolution

In neurons, ____________ receive signals and ____________ transmit signals. A. cell body; axons B. dendrites; axons C. cell body; dendrites D. axons; dendrites

B. dendrites; axons

Photoreceptors are found in your _______________, whereas chemoreceptors are found in your _______________. A. skin; ears B. eyes; nose and mouth C. eyes; ears D. skin; nose and mouth

B. eyes; nose and mouth

The connection between form and ______ is a basic concept of biology. A. environment B. function C. adaptation D. structure

B. function

Which of the following lists (in order) the four stages of food processing? A. digestion, ingestion, absorption, elimination B. ingestion, digestion, absorption, elimination C. ingestion, absorption, elimination, digestion D. ingestion, digestion, elimination, absorption

B. ingestion, digestion, absorption, elimination

The organ of Corti is in the ______. A. Eustachian tube B. inner ear C. outer ear D. middle ear

B. inner ear

A person who has a stroke that damages the cerebellum might have difficulty ____________ A. regulating breathing rate B. learning and coordinating motor movements C. recalling emotional memories D. coordinating homeostatic regulation of thirst and hunger

B. learning and coordinating motor movements

The transmission of a nerve impulse first triggers the _____. A. action of the sodium-potassium pump B. opening of voltage-gated sodium channels and the diffusion of sodium ions into the neuron C. opening of voltage-gated sodium channels and the diffusion of sodium ions out of the neuron D. opening of voltage-gated potassium channels and the diffusion of potassium ions out of the neuron E. opening of voltage-gated potassium channels and the diffusion of potassium ions into the neuron

B. opening of voltage-gated sodium channels and the diffusion of sodium ions into the neuron

A(n) _____ is the contractile unit of skeletal muscle. A. thick filament B. sarcomere C. myosin filament D. thin filament E. actin filament

B. sarcomere

Animals that possess homologous structures probably __________. A. by chance had similar mutations in the past B. shared a common ancestor C. have increased genetic diversity D. are headed for extinction

B. shared a common ancestor

Absorption of food monomers occurs primarily in the _____. A. lining of the oral cavity and the esophagus B. small intestine C. stomach D. large intestine

B. small intestine

Realizing that you did not study as much as you needed to for this exam, you start to take the test. However, it is difficult to concentrate because your heart is racing, your stomach seems tied in a knot, you are breathing too quickly, and your mouth is dry. Most likely, you are experiencing the effects of the ______. A. central nervous system B. sympathetic nervous system C. somatic nervous system D. parasympathetic nervous system

B. sympathetic nervous system

The ________________ directs the flow of information between the cerebrum and brain stem. A. cerebellum B. thalamus C. hypothalamus D. pons

B. thalamus

When a neuron is at its resting potential A. sodium-potassium pumps transport sodium ions into the cell. B. there are more potassium ions inside the neuron than outside. C. sodium-potassium pumps transport both sodium and potassium ions out of the cell. D. gated sodium channels are open. E. the inside of the cell is positively charged relative to the outside.

B. there are more potassium ions inside the neuron than outside.

Which of the following is a true statement? A. As dinosaurs became extinct, reptiles remained as their sole descendants. B. Pangaea started to break up to form geographic isolation for many species about 65 million years ago. C. Massive extinction of species results in less species diversity but is followed by an explosive diversification of certain remaining species. D. Mammals were the prominent species just before the extinction of dinosaurs.

C. Massive extinction of species results in less species diversity but is followed by an explosive diversification of certain remaining species.

What causes the inside of a membrane to become positively charged during an action potential? A. Positively charged ions rush in, and negatively charged ions rush out. B. Negatively charged ions rush out. C. Positively charged ions rush in. D. Negatively charged ions rush in.

C. Positively charged ions rush in.

A baby is born with the normal number and distribution of rods, but no cones. We would expect that the baby's vision would be __________. A. normal on the right side of the visual field but totally blind on the left side B. perfectly fine C. color-blind, easily blinded by bright light, and capable only of coarse resolving power D. normal on the left side of the visual field but blurred and gray on the right side E. absent; the baby would be totally blind

C. color-blind, easily blinded by bright light, and capable only of coarse resolving power

Signal transduction involves ____________. A. convergence of multiple stimuli at a single receptor B. rerouting of a stimulus to appropriate receptors C. conversion of a stimulus to an electrical signal D. jamming of signals by neurons

C. conversion of a stimulus to an electrical signal

Organs that come into contact with the environment are lined with which one of the following types of tissue? A. loose connective B. adipose C. epithelial D. smooth muscle E. skin

C. epithelial

Homeostasis is the __________. A. correlation of structure and function B. exchange of materials with the surrounding environment C. maintenance of a relatively constant internal environment D. idea that all vertebrates are built in a similar way E. cooperation of body parts to form tissues, organs, and systems

C. maintenance of a relatively constant internal environment

In _____ isolation, it is physically impossible for two species to mate with each other, often because their genitalia do not fit together properly. A. behavioral B. temporal C. mechanical D. habitat

C. mechanical

Chyme enters the small intestine from the stomach. At this point, _____. A. most absorption is complete, but mechanical processing is still required B. digestion and absorption are complete; the next step is elimination C. mechanical digestion is essentially complete, but the other processes are ongoing or have not yet begun D. the only remaining steps are absorption of excess water and elimination

C. mechanical digestion is essentially complete, but the other processes are ongoing or have not yet begun

Alzheimer's disease is characterized by ______. A. extreme mood swings B. increased energy and extreme talkativeness C. mental deterioration, memory loss, and personality changes D. loss of energy and suicidal thoughts

C. mental deterioration, memory loss, and personality changes

Starch is a type of _____. A. disaccharide B. nucleotide C. polysaccharide D. fatty acid E. monosaccharide

C. polysaccharide

A stimulus has opened the voltage-gated sodium channels in an area of a neuron's plasma membrane. As a result, _____ rushes into the neuron and diffuses to adjacent areas; this in turn results in the _____ in the adjacent areas. A. potassium ... opening of voltage-gated potassium channels B. sodium ... opening of voltage-gated potassium channels C. sodium ... opening of voltage-gated sodium channels D. sodium ... closing of voltage-gated sodium channels E. potassium ... opening of voltage-gated sodium channels

C. sodium ... opening of voltage-gated sodium channels

Protein digestion begins in the _____. A. mouth B. esophagus C. stomach D. small intestine E. large intestine

C. stomach

The naming and classifying of organisms is called _____. A. gradualism B. genetics C. taxonomy D. biology E. polyploidy

C. taxonomy

The ________________ directs the flow of information between the cerebrum and brain stem. A. pons B. hypothalamus C. thalamus D. cerebellum

C. thalamus

Most nutrient absorption occurs in which part of the digestive system? A. stomach B. duodenum C. the several meters of the small intestine that come after the duodenum D. large intestine

C. the several meters of the small intestine that come after the duodenum

A switch is to a light, as a ____________________ is to an action potential. A. neuron B. axon C. threshold D. membrane potential

C. threshold

A neuron has a resting potential of about _____ millivolts. A. +50 B. +35 C. -55 D. -70 E. -80

D. -70

Uranium-235, with a half-life of 713,000,000 years, decays to lead-207. If a rock sample is determined to have one-quarter of the uranium-235 content it had when it formed, the age of the rock sample can be estimated to be approximately ______ years old. A. 178 million B. 713 million C. 28.5 billion D. 1.4 billion

D. 1.4 billion

What is the main digestive function of the pancreas? A. It secretes mucus into the small intestine. B. It produces bile. C. It produces digestive enzymes and bile. D. It produces digestive enzymes and neutralizes stomach acids.

D. It produces digestive enzymes and neutralizes stomach acids.

Which of the following events is the first to occur during an action potential? A. Potassium channels open. B. Sodium ions flow into the neuron, making the inside of the neuron positively charged relative to the outside. C. Sodium channels close. D. Sodium channels open. E. Potassium ions flow out of the neuron.

D. Sodium channels open.

_____ is(are) a type of mechanoreceptor. A. Taste buds B. Cone cells C. Rod cells D. Stretch receptors E. The retina

D. Stretch receptors

Which one of the following statements is true? A. Cones are more sensitive to light than rods. B. Rods can distinguish color. C. The best way to see stars is to look straight at them. D. There are three different types of cones in the human eye.

D. There are three different types of cones in the human eye.

Which of the following statements apply to freshwater fish? A. They pump out ions via the gills. B. They lose water by osmosis. C. The concentration of solutes in their internal fluids is lower than in the surrounding water. D. They produce dilute urine.

D. They produce dilute urine.

The rapid reversal of ions across the plasma membrane of a neuron is known as a(n) __________. A. resting potential B. membrane potential C. threshold D. action potential

D. action potential

When digested, proteins are broken down into _____. A. glycerol only B. fatty acids only C. monosaccharides D. amino acids E. both glycerol and fatty acids

D. amino acids

Which of these enzymes begins the breakdown of starch? A. bile B. disaccharidases C. lipase D. amylase E. nucleases

D. amylase

Which of these causes the release of neurotransmitter molecules? A. the receipt of a signal from the postsynaptic neuron B. the opening of voltage-regulated calcium channels and the diffusion of calcium ions out of the neuron C. an action potential reaching the end of the cell body D. an action potential reaching the end of the axon E. an action potential reaching the end of the dendrite

D. an action potential reaching the end of the axon

The parasympathetic division of the nervous system is part of the __________. A. autonomic nervous system component of the central nervous system B. somatic nervous system component of the central nervous system C. somatic nervous system component of the peripheral nervous system D. autonomic nervous system component of the peripheral nervous system

D. autonomic nervous system component of the peripheral nervous system

Which of the following is the usual cause of heartburn? A. compression of the lower esophagus by an overfilled stomach B. retention of food at the bottom of the esophagus by a sphincter that is reluctant to open C. irritation of the lower esophagus by substances in spicy food D. backflow of chyme from the stomach into the esophagus

D. backflow of chyme from the stomach into the esophagus

Which of these is NOT one of the four major categories of tissue? A. muscle B. epithelial C. connective D. blood E. nervous

D. blood

If the dendrites are the "ears" of a neuron, and the axon is the "mouth" of the neuron, what is the "cell body" analogous to? A. hands B. neck C. nose D. brain

D. brain

Our receptors for taste, smell, and hearing are, respectively, __________. A. chemoreceptor, chemoreceptor, and electromagnetic receptor B. thermoreceptor, chemoreceptor, and electromagnetic receptor C. thermoreceptor, chemoreceptor, and mechanoreceptor D. chemoreceptor, chemoreceptor, and mechanoreceptor E. mechanoreceptor, chemoreceptor, and mechanoreceptor

D. chemoreceptor, chemoreceptor, and mechanoreceptor

Homology is evidence of ______. A. convergent evolution B. punctuated evolution C. paedomorphosis D. common ancestry

D. common ancestry

Analogous structures are evidence of ______. A. divergent evolution B. stabilizing selection C. common ancestry D. convergent evolution

D. convergent evolution

Photoreceptors are a type of ______________. A. chemoreceptor B. thermoreceptor C. mechanoreceptor D. electromagnetic receptor

D. electromagnetic receptor

Which of the following nutrients begins undergoing digestion only when it reaches the small intestine? A. starch B. complex carbohydrate C. protein D. fat

D. fat

The cerebrum develops from the _______________ A. hindbrain B. midbrain C. brain stem D. forebrain

D. forebrain

Your small intestine can absorb ____ without their being further digested. A. starches B. fats C. proteins D. fructoses E. nucleic acids

D. fructoses

The ____________________ is the master control center for the endocrine system. A. midbrain B. thalamus C. medulla oblongata D. hypothalamus

D. hypothalamus

The ____________________ is the master control center for the endocrine system. A. thalamus B. medulla oblongata C. midbrain D. hypothalamus

D. hypothalamus

Which one of the following correctly pairs the structure with its major function(s)? A. cerebellum-regulates memory, learning, and speech B. thalamus-coordinates balance C. brainstem-input center for sensory data going to the cerebrum D. hypothalamus-regulates body temperature, blood pressure, and hunger

D. hypothalamus-regulates body temperature, blood pressure, and hunger

Macroevolution includes __________. A. adaptation of populations over the short term B. loss of features such as feathers C. merging of species D. increase in the number of species over time E. extinction of a single species

D. increase in the number of species over time

A person who has a stroke that damages the cerebellum might have difficulty ____________ A. regulating breathing rate B. coordinating homeostatic regulation of thirst and hunger C. recalling emotional memories D. learning and coordinating motor movements

D. learning and coordinating motor movements

The brain stem consists of the ____________. A. medulla oblongata, hypothalamus, and thalamus B. medulla oblongata, pons, and cerebellum C. medulla oblongata, pons, and hypothalamus D. medulla oblongata, pons, and midbrain

D. medulla oblongata, pons, and midbrain

A muscle cell contains bundles of long A. sarcomeres. B. calcium ions. C. muscle fibers. D. myofibrils. E. action potentials.

D. myofibrils.

Which lists the major segments of the alimentary canal in the correct order? A. oral cavity, stomach, esophagus, small intestine, large intestine B. esophagus, oral cavity, stomach, small intestine, large intestine C. oral cavity, esophagus, stomach, large intestine, small intestine D. oral cavity, esophagus, stomach, small intestine, large intestine

D. oral cavity, esophagus, stomach, small intestine, large intestine

Which of the following levels of structure encompasses all the others? A. organ system B. cell C. tissue D. organism E. organ

D. organism

A nerve poison that blocked neurotransmitter receptors on the dendrites would __________. A. inhibit the regeneration of neurotransmitter for use by the synaptic terminals B. cause continued stimulation of the membrane of the receiving neuron D. prevent transmission across the synaptic cleft E. reverse the flow of information

D. prevent transmission across the synaptic cleft

The Cretaceous extinctions were followed by the __________. A. adaptive radiation of dinosaurs B. appearance of the first land plants C. appearance of hard-shelled marine organisms D. rapid diversification of mammals and birds E. appearance of insects

D. rapid diversification of mammals and birds

In humans, the photoreceptors of the eye are found on the _____. A. blind spot B. sclera C. iris D. retina E. lens

D. retina

You reach for a rose and suddenly feel the poke of a thorn. Feeling unexpected pain, you quickly withdraw your hand. Which of the following is the correct sequence of functions of the nervous system that occurred? A. motor output, integration, sensory input B. integration, sensory input, motor output C. motor output, sensory input, integration D. sensory input, integration, motor output E. integration, motor output, sensory input

D. sensory input, integration, motor output

Imagine an invertebrate that lives in an estuary where salinity varies cyclically with the tides. If this animal practices homeostasis with respect to the salt concentration of its body fluids, its salt concentration will show ______. A. a cyclic variation identical to that of the surrounding water B. no variations C. slight variations, but only when the external salinity is changing rapidly D. slight, continuous fluctuations

D. slight, continuous fluctuations

Several important enzymes and other secretions aid in digestion as food moves down the alimentary canal, as follows: in the oral cavity, salivary amylase helps break down _____; in the stomach, pepsin helps break down _____; and in the small intestine, bile helps break down _____. A. fats and oils; proteins; starches B. starches; fats and oils; proteins C. proteins; starches; fats and oils D. starches; proteins; fats and oils

D. starches; proteins; fats and oils

The resting potential of a resting neuron is defined as __________. A. the stimulus B. the action potential C. a synaptic cleft D. the difference in charge across the plasma membrane of a resting neuron

D. the difference in charge across the plasma membrane of a resting neuron

At rest, which of these plays a role in establishing the charge differential across a neuron's plasma membrane? A. the sodium-potassium pump moving sodium ions into the neuron and potassium ions out of the neuron B. the diffusion of sodium ions out of the neuron C. the diffusion of potassium ions into the neuron D. the sodium-potassium pump moving sodium ions out of the neuron and potassium ions into the neuron E. the diffusion of sodium ions into the neuron

D. the sodium-potassium pump moving sodium ions out of the neuron and potassium ions into the neuron

What is the main component of gastric juice? A. inactive pepsin B. amylase C. hydrochloric acid D. water E. bile

D. water

_____ is secreted by the _____ and acts to emulsify _____ in the _____. A. Lipase ... small intestine ... fats ... small intestine B. Trypsin ... pancreas ... fats ... small intestine C. Nucleases ... pancreas ... nucleic acids ... stomach D. Amylase ... salivary glands ... starch ... stomach E. Bile ... liver ... fats ... small intestine

E. Bile ... liver ... fats ... small intestine

What causes an action potential to be conducted along a neuron's axon? A. The change in charge difference across the membrane spreads from open potassium channels, causing sodium channels farther along the axon to open. B. The change in charge difference across the membrane spreads from open sodium channels, causing the sodium-potassium pumps to move ions across the neuron's membrane. C. The axon returns to its resting potential. D. The change in charge difference across the membrane spreads from open potassium channels, causing potassium channels farther along the axon to open. E. The change in charge difference across the membrane spreads from open sodium channels, causing sodium channels farther along the axon to open.

E. The change in charge difference across the membrane spreads from open sodium channels, causing sodium channels farther along the axon to open.

Which of these is an example of negative feedback? A. The first enzyme in a reaction sequence lowers the activation energy of the reaction. B. The end product of a reaction sequence speeds up the reaction sequence. C. The end product of a reaction sequence has no effect on the reaction sequence. D. The first enzyme in a reaction sequence makes the free energy change of the reaction more negative. E. The end product of a reaction sequence shuts down the reaction sequence.

E. The end product of a reaction sequence shuts down the reaction sequence.

When digested, fats are broken down into _____. A. glycerol only B. fatty acids only C. monosaccharides D. amino acids E. both glycerol and fatty acids

E. both glycerol and fatty acids

Starch can be broken down into the disaccharide known as _____. A. lactose B. glucose C. sucrose D. fructose E. maltose

E. maltose

Sodium-potassium pumps A. do not require energy from ATP. B. are open all the time, allowing potassium ions to leave the cell. C. move both sodium and potassium ions into the cell. D. move only sodium ions into the cell. E. restore the distribution of ions inside and outside a neuron's membrane following an action potential.

E. restore the distribution of ions inside and outside a neuron's membrane following an action potential.

Neurons store neurotransmitter molecules in vesicles located within _____. A. the cell body B. myelin C. the synaptic cleft D. dendrites E. synaptic terminals

E. synaptic terminals

When a sarcomere contracts A. calcium ions bind to myosin. B. actin heads bind to and pull myosin. C. the myosin-binding sites on actin are blocked by another protein. D. no ATP is required. E. the actin and myosin filaments do not change in length.

E. the actin and myosin filaments do not change in length.

When ATP attaches to a myosin head, A. calcium ions are released from the endoplasmic reticulum. B. the muscle relaxes. C. the myosin head pulls the actin filament, shortening the sarcomere. D. the myosin head extends. E. the myosin head detaches from actin.

E. the myosin head detaches from actin.