Bio 2 Final Exam Practice (2)

Which of the following agents of evolution adapts populations to their environment?
A. Natural selection
B. Nonrandom mating
C. Gene flow
D. Genetic drift

Natural selection

Which of the following statements is false?
A. Darwin's theory of evolution by natural selection was influenced by his experiences as a pigeon breeder.
B. Individuals evolve according to Darwin's theory.
C. Death rates in nature are usually high.
D. Offspring tend to resemble their parents.

Individuals evolve according to Darwin's theory

In a hypothetical population of sawflies, 20 percent is homozygous for allele a. Assuming that A and a are the only alleles at this locus, what percent of the population is heterozygous?
A. 10 percent
B. 20 percent
C. 35 percent
D. 45 percent

35 percent

Assuming that there are only two alleles at a given locus, if the frequency of one allele is 0.6, what is the frequency of the other allele?
A. -0.6
B. 0
C. 0.4
D. 0.6
E. 1

0.4

The ultimate origin of genetic variation is
A. genetic drift
B. mutation
C. natural selection
D. nonrandom mating

mutation

If a population with two alleles is at Hardy-Weinberg equilibrium and the frequency of one allele is 0.7, what is the heterozygote frequency?
A. 0.7
B. 0.42
C. 0.3
D. 0.21

0.42

Which of the following is not required for a population at Hardy-Weinberg equilibrium?
A. There is no migration between populations
B. Natural Selections is not acting on the alleles in the population
C. Mating is random
D. Multiple alleles must be present at every locus

Multiple alleles must be present at every locus

Due to various causes, including DDT poisoning, the population size of whooping cranes was reduced to about a dozen during the 1970s. The population size has since rebounded, and there are now hundreds of whooping cranes. Which of the following would you not expect to see in whooping cranes?
A. Very low levels of genetic variation
B. Very few heterozygous individuals
C. Differences in allele frequency between current populations of cranes and historical populations
D. Considerable genetic polymorphism

Considerable genetic polymorphism

Natural selection works \_______ on the genotype and \_______ on the phenotype.
A. directly; directly
B. directly; indirectly
C. directly; not at all
D. indirectly; directly

indirectly; directly

Which of the following modes of selection arises when individuals at both extremes of the distribution have high fitness?
A. Stabilizing selection
B. Directional selection
C. Disruptive selection
D. Both a and b

Disruptive selection

Suppose that females of a species of beetles prefer to mate with males that have relatively rare color patterns. This observation would be an illustration of
A. genetic drift.
B. the founder effect.
C. frequency-dependent selection.
D. disruptive selection.

frequency-dependent selection

Random genetic drift would probably have its greatest effect on a
A. small, isolated population.
B. large population in which mating is nonrandom.
C. large population in which mating is random.
D. large population with regular immigration from a neighboring population.

small, isolated population

As adaptions for flight, the wings of bats and the wings of birds are an example of
A. synapomorphy.
B. monophyly.
C. paraphyly.
D. convergent evolution.

convergent evolution

The common ancestor of humans and the other "great apes" walked on all fours, while humans are bipeds. Bipedalism is thus the \_______ trait.
A. ancestral
B. homoplasic
C. synapomorphic
D. derived

derived

A taxon that includes a common ancestor, all descendants of that ancestor, and no other organisms is considered to be
A. paraphyletic.
B. polyphyletic.
C. monogamous.
D. monophyletic.

monophyletic

The \_______ species concept holds that "species are groups of actually or potentially interbreeding natural populations that are reproductively isolated from other
A. Darwinian
B. biological
C. morphological
D. Linnaean

biological

Geographical speciation is also known as
A. reinforcement.
B. sympatric speciation.
C. Darwinian speciation.
D. allopatric speciation.

allopatric speciation

What was Darwin's explanation for the evolution of bright colors and other apparently useless (and potentially deleterious) but conspicuous characters in
A. Stabilizing selection
B. Genetic drift
C. Sexual selection
D. Gene flow

Sexual selection

Which of the following factors led to the diversification of Darwin's finches?
A. Environmental conditions are the same among the different islands.
B. Most of the islands are sufficiently distant from one another such that dispersal among populations on different islands is limited.
C. Because the Galápagos Islands are only 100 km from Ecuador, they receive a continual input of new genes from the mainland.
D. Birds can easily move from one island to another.

Most of the islands are sufficiently distant from one another such that dispersal among populations on different islands is limited.

The most common means of sympatric speciation occurs via
A. geographic barriers.
B. the hawthorn process.
C. disruptive selection.
D. polyploidy.

polyploidy

Females of the species Drosophila pseudoobscura respond less well to courtship signals from males of their close relative D. persimilis than they do to those of males of their own species. This is an example of
A. gametic isolation.
B. hybrid infertility.
C. behavioral isolation.
D. adaptive radiation.

behavioral isolation

Which of the following is not a postzygotic isolation mechanism?
A. Abnormal meiosis following fertilization
B. Infertile hybrids
C. Reduced viability of hybrids
D. Variation in mating pheromones

Variation in mating pheromones

When hybrid offspring are at a fitness disadvantage and reinforcement does not occur, which of the following is likely to occur?
A. The spreading of hybrids through both populations, resulting in the combining of both gene pools and no new species
B. An adaptive radiation
C. The formation of a new species via polyploidy
D. The formation of a hybrid zone

The formation of a hybrid zone

What must be true of any organ that is described as vestigial?
A. It need be neither homologous nor analogous to some feature in an ancestor.
B. It must be analogous to some feature in an ancestor.
C. It must be homologous and analogous to some feature in an ancestor.
D. It must be homologous to some feature in an ancestor.

It must be homologous to some feature in an ancestor.

Which of the following statements about HIV or AIDS is false?
A. AIDS is a zoonotic disease.
B. HIV likely entered into humans from only one animal species.
C. HIV likely entered human populations from hunters who cut themselves as they were skinning animals.
D. HIV likely originated in Africa.

HIV likely entered into humans from only one animal species.

Select the best answer from the choices listed that describes punctuated equilibrium. It is an evolutionary process that involves
A. gradual change observable in the fossil record with very little if any stasis.
B. "spurts" of change observable in the fossil record followed by periods of stasis.
C. gradual change observable in the fossil record followed by periods of stasis.
D. "spurts" of change observable in the fossil record with very little if any stasis.

"spurts" of change observable in the fossil record followed by periods of stasis.

The most direct ancestors of land plants were probably \_____.
A. kelp (brown alga) that formed large beds near the shorelines
B. photosynthesizing prokaryotes (cyanobacteria)
C. green algae
D. liverworts and mosses

green algae

Vascular plant tissue includes all of the following cell types
A. cambium cells.
B. vessel elements
C. companion cells.
D. sieve cells.

cambium cells

Tracheids, vessel elements, and sclereids are similar in that they all
A. lack secondary cell walls.
B. conduct water and minerals.
C. function when dead.
D. have open ends

function when dead

Trichomes \_____.
A. repel or trap insects
B. open and close to allow gas exchange
C. absorb sunlight, increasing the temperature of leaves
D. increase water loss from leaves

repel or trap insects

Which of the following is (are) unique to animals?
A. Heterotrophy.
B. Nervous conduction.
C. Flagellated gametes.
D. Cells that have mitochondria.

Nervous conduction

What do animals as diverse as corals and monkeys have in common?
A. Body cavity between body wall and digestive system.
B. Presence of Hox genes.
C. Type of body symmetry.
D. Number of embryonic tissue layers.

Presence of Hot genes

Which of the following traits is not shared by all animals?
A. Specific types of cell-cell junctions.
B. A common set of extracellular matrix molecules.
C. A complete gut.
D. Similarities in their Hox genes.

A complete gut

Contact of a sperm with signal molecules in the coat of an egg causes the sperm to undergo
A. depolarization.
B. apoptosis.
C. vitellogenesis.
D. acrosomal reaction.

acrosomal reaction

Even in the absence of sperm, metabolic activity in an egg can be artificially activated by
A. injection of calcium ions into the cytosol.
B. exposure to the low pH of the uterus.
C. abnormally high levels of carbonic acid in the cytosol.
D. depletion of its ATP supplies.

injection of calcium ions into the cytosol

The first cavity formed during sea urchin development is the
A. anus.
B. blastocoel.
C. mouth.
D. blastopore.

blastocoel

Changes in both cell shape and cell position occur extensively during
A. cleavage, but not gastrulation or organogenesis.
B. gastrulation, but not organogenesis or cleavage.
C. organogenesis, but not gastrulation or cleavage.
D. gastrulation, organogenesis, and cleavage.

gastrulation, organogenesis, and cleavage

In a frog embryo, gastrulation
A. occurs along the primitive streak in the animal hemisphere.
B. occurs within the inner cell mass that is embedded in the large amount of yolk.
C. produces a blastocoel displaced into the animal hemisphere.
D. proceeds by involution as cells roll over the lip of the blastopore.

proceeds by involution as cells roll over the lip of the blastopore

The protein of the bicoid gene in Drosophila determines the \_____ of the embryo.
A. anterior-posterior axis
B. anterior-lateral axis
C. posterior-dorsal axis
D. posterior-ventral axis

anterior-posterior axis

Which of the following cells develops into a human embryo?
A. Trophoblast
B. Extraembryonic membrane
C. Inner cell mass
D. Cumulus

Inner cell mass

Which of the following is not derived from mesoderm?
A. Blood
B. Heart
C. Notochord
D. Spinal cord

Spinal cord

Which of the following directors of embryonic development can be found within unfertilized eggs?
A. Tissue-specific proteins
B. Cytoplasmic determinants
C. Binding protein
D. mRNAs transcribed from embryonic genome

Cytoplasmic determinants

To prepare flight muscles for use on a cool morning, hawkmoths
A. rapidly contract and relax these muscles to generate metabolic warmth.
B. decrease their standard metabolic rate.
C. walks to shaded areas to avoid direct sunlight.
D. relaxes the muscles completely until after they launch themselves into the air

rapidly contract and relax these muscles to generate metabolic warmth

Panting by an overheated dog achieves cooling by
A. shivering thermogenesis.
B. torpor.
C. evaporation.
D. acclimatization.

evaporation

Most biological Q10 values are between \_______ and \_______.
A. 0; 1
B. 1; 2
C. 2; 3
D. 2; 10

2;3

Mammals and birds eat more often than reptiles. Which of the following traits shared by mammals and birds best explains this habit?
A. Endothermy
B. Ectothermy
C. Amniotic egg
D. Terrestrial

Endothermy

Which of the following is the thermoregulatory response of the hypothalamus to a rise in temperature?
A. Increased metabolic heat production.
B. Dilation of blood vessels in the skin.
C. Resetting of the thermostat to a higher setting.
D. Overall increase in body temperature

Dilation of blood vessels in the skin.

The body's automatic tendency to maintain a constant and optimal internal environment is termed \_____.
A. static equilibrium
B. balanced equilibrium
C. physiological chance
D. homeostasis

homeostasis

A woman standing and watching the stars on a cool, calm night will lose most of her body heat by \_____.
A. Radiation
B. Evaporation
C. Conduction
D. Convection

Radiation

The process by which water is "pulled" up through the xylem columns of plants as it evaporates out of the leaves is called
A. respiration. B. transpiration.
C. osmosis.
D. anhydration.

transpiration

Pollination begins when pollen is transferred from the \________ to the \________ of a flower.
A. anther, ovary
B. anther, receptacle
C. anther, stigma
D. stigma, embryo sac

anther, stigma

Endosperm tissue of angiosperms has what ploidy level?
A. n
B. 2n
C. 3n
D. 4n

3n

Which structure does NOT represent a mode
of vegetative reproduction?
A. runners
B. rhizoids
C. adventitious plantlets D. stolons

rhizoids

The angiosperm carpel serves to
A. protects the ovules and seeds.
B. attracts pollinators.
C. produces sugars via photosynthesis.
D. prevents cross-pollination

protects the ovules and seeds

Which of the following can be found in gymnosperms?
A. Pollen
B. Fruits
C. Carpels
D. Triploid endosperm

Pollen

Angiosperm double fertilization is so-called because it features the formation of
A. one embryo from one egg fertilized by two sperm cells.
B. one embryo involving one sperm cell and an endosperm involving a second sperm cell.
C. two embryos from one egg and two sperm cells.
D. two embryos from two sperm cells and two eggs.

one embryo involving one sperm cell and an endosperm involving a second sperm cell

Turgor is most directly related to the plant cells'
A. total water potential.
B. pressure potential.
C. solute potential.
D. osmosis

pressure potential

Which of these characteristics does not promote outcrossing in flowering plants?
A. Self-incompatibility
B. Dioecism
C. Physical separation of flower parts
D. Apomixis

Apomixis

Which process makes the water potential in a leaf more negative?
A. The pressure placed on the leaf by the cuticle.
B. The evaporation of water from mesophyll cells.
C. The movement of water into the leaf by root pressure.
D. The increased K+ pumped out of guard cells.

The evaporation of water from mesophyll cells.

All of the following have an effect on water potential (Ψ) in plants except
A. physical pressure.
B. osmosis.
C. dissolved solutes.
D. DNA structure

DNA structure

In which plant cell or tissue would the pressure component of water potential most often be negative?
A. Root cortex cell
B. Stem phloem
C. Root epidermis
D. Stem xylem

Stem xylem

The opening of stomata is thought to involve
A. active transport of water out of the guard cells.
B. a decrease in the solute concentration of the stoma.
C. an increase in the solute concentration of the guard cells.
D. decreased turgor pressure in guard cells.

an increase in the solute concentration of the guard cells

Water moves through a plant by each of the following methods except
A. from cell to cell through plasmodesmata.
B. through the Casparian strip.
C. through the spaces between cells.
D. from cell to cell across plasma membranes

through the Casparian strip

Which of the following is the correct order of floral organs from the outside to the inside of a complete flower?
A. Sepals-petals-stamens-carpels.
B. Sepals-stamens-petals-carpels.
C. Petals-sepals-stamens-carpels.
D. Petals-stamens-sepals-carpels

Sepals-petals-stamens-carpels

The function of the pollen tube is to
A. eject pollen from the microsporangium.
B. direct pollen to the megasporangium.
C. digest the sporophyte tissue as it elongates toward the female gametophyte.
D. produce pollen

digest the sporophyte tissue as it elongates toward the female gametophyte

In mammals, most gas exchange between the atmosphere and the pulmonary blood occurs in the
A. larynx.
B. alveoli.
C. bronchioles.
D. bronchi.

alveoli

Sponges, cnidarians, and flatworms lack a specialized gas exchange surface because
A. they do not produce carbon dioxide.
B. countercurrent exchange mechanisms cannot function well in their living conditions.
C. they are too large for a circulatory system to operate well.
D. nearly all of their cells are in direct contact with the external environment.

nearly all of their cells are in direct contact with the external environment

Air rushes into the lungs of humans during inhalation because
A. the rib muscles and diaphragm contract, increasing the lung volume.
B. pulmonary muscles contract and pull on the outer surface of the lungs.
C. gas flows from a region of lower pressure to a region of higher pressure.
D. the volume of the alveoli increases as smooth muscles contract.

the rib muscles and diaphragm contract, increasing the lung volume.

An increase from pH 7.2 to pH 7.4 around hemoglobin causes
A. an increase in the binding affinity of hemoglobin to hydrogen molecules.
B. an increase in the binding affinity of hemoglobin to oxygen molecules.
C. hemoglobin to give up its oxygen molecules.
D. hemoglobin to denature

an increase in the binding affinity of hemoglobin to oxygen molecules

The largest proportion of CO2 carried by the blood is in the form of
A. bicarbonate ions (HCO3-) carried in the plasma.
B. molecular CO2 dissolved in the plasma.
C. bicarbonate ions (HCO3-) carried within the red blood cells
D. molecular CO2 chemically bound to hemoglobin

bicarbonate ions (HCO3-) carried in the plasma.

In the evolution of the vertebrate circulatory system, a transitional step led to separate pulmonary and systemic circuits. This step can be observed in
A. lungfish.
B. mammals.
C. birds.
D. amphibians

lunfish

The diversity among antibodies occurs mainly through
A. posttranslational modifications.
B. protein-folding differences.
C. different patterns of methylation.
D. DNA changes

DNA changes

Acidity in human sweat is an example of
A. antibody activation.
B. acquired immunity.
C. adaptive immunity.
D. innate immunity.

innate immunity

Interactions between macrophages and lymphocytes are coordinated by
A. antibodies.
B. T cell receptors.
C. mast cells.
D. MHC proteins.

MHC proteins

The activation of helper T cells is likely
A. when an antigen is displayed by a dendritic cell.
B. when a cytotoxic T cell releases cytokines.
C. when B cells respond to T-independent antigens.
D. when natural killer cells come in contact with a tumor cell.

when a cytotoxic T cell releases cytokines

Among the last line of defenses against prolonged exposure to an extracellular pathogen is
A. lysis by natural killer cells.
B. phagocytosis by neutrophils.
C. antibody production by plasma cells.
D. histamine release by basophils.

antibody production by plasma cells

Select the pathway that would lead to the activation of cytotoxic T cells.
A. B cell contact antigen, helper T cell is activated, clonal selection occurs.
B. Complement is secreted, B cell contacts antigen, helper T cell activated, cytokines released.
C. Body cell becomes infected with a virus, new viral proteins appear, class I MHC molecule-antigen complex displayed on cell surface.
D. cytotoxic T cells, class II MHC molecule-antigen complex displayed, cytokines released, cell lysis

Body cell becomes infected with a virus, new viral proteins appear, class I MHC molecule-antigen complex displayed on cell surface

Which of the following does not arise from a myeloid progenitor cell?
A. Macrophage
B. T lymphocyte
C. Basophil
D. Mast cell

T lymphocyte

Which of the following statements about natural killer cells is false?
A. They are a class of lymphocytes.
B. They can distinguish between normal cells and cells that have been infected by viruses.
C. They release cytokines.
D. They initiate lysis of targeted cells

They release cytokines

The body fluids of an osmoconformer would be \________ with its \________ environment.
A. isoosmotic; saltwater
B. isotonic; freshwater
C. hyperosmotic; saltwater
D. hyperosmotic; freshwater

isoosmotic; saltwater

Birds that live in marine environments and thus lack access to fresh drinking water
A. drinks seawater and secrete excess ions through their kidneys only.
B. drinks seawater and secrete excess ions mainly through their nasal salt glands.
C. obtains water by eating only osmoregulating prey.
D. osmoregulates without using a transport epithelium for this purpose.

drinks seawater and secrete excess ions mainly through their nasal salt glands.

The nitrogenous waste that requires the most energy to produce is
A. ammonium.
B. ammonia.
C. urea.
D. uric acid.

uric acid

An excretory system that is partly based on the filtration of fluid under high hydrostatic pressure is the
A. Malpighian tubules of insects.
B. kidneys of vertebrates.
C. flame bulb system of flatworms.
D. metanephridia of earthworms.

kidneys of vertebrates

Processing of filtrate in the proximal and distal tubules
A. regulates the speed of blood flow through the nephrons.
B. maintains homeostasis of pH in body fluids.
C. reabsorbs urea to maintain osmotic balance.
D. achieves the conversion of toxic ammonia to less toxic urea

maintains homeostasis of pH in body fluids

Increased ADH secretion is likely after
A. blood pressure is abnormally high.
B. ingestion of ethanol (drinking alcoholic drinks).
C. eating a small sugary snack.
D. sweating-induced dehydration increases plasma osmolarity.

sweating-induced dehydration increases plasma osmolarity.

Blood enters a nephron's vascular component by way of the
A. peritubular capillaries.
B. glomerulus.
C. efferent arteriole.
D. afferent arteriole

afferent arteriole

\_______________ is an excretory system that actively transports uric acid and ions into blind tubules found in insects and most terrestrial arthropods.
A. Protonephridia
B. Metanephridia
C. Malpighian tubule
D. Nephron

Malpighian tubule

Which of the following is not a factor in the movement of water into tissues?
A. Osmotic gradient
B. Fluid pressure
C. Active transport of water
D. Diffusion

Active transport of water

The functional unit of the kidney is
A. Bowman's capsule.
B. a capillary.
C. the glomerulus.
D. the nephron

the nephron

. The "threshold" potential of a membrane
A. is the peak amount of depolarization seen in an action potential.
B. is the lowest frequency of action potentials a neuron can produce.
C. is the minimum hyperpolarization needed to prevent the occurrence of action potentials.
D. is the minimum depolarization needed to operate the voltage-gated sodium channels

is the minimum depolarization needs to operate the voltage-gated sodium channels

A simple nervous system
A. must include chemical senses, mechanoreception, and vision.
B. includes sensory information, an integrating center, and effectors.
C. has information flow in only one direction: toward an integrating center.
D. has information flow in only one direction: away from an integrating center

includes sensory information, an integrating center, and effectors.

In a simple synapse, neurotransmitter chemicals are released by
A. cell bodies.
B. axon hillocks.
C. dendritic membrane.
D. presynaptic membrane

presynaptic membrane

A graded hyperpolarization of a membrane can be induced by
A. increasing its membrane's permeability to Ca2+.
B. increasing its membrane's permeability to K+.
C. increasing its membrane's permeability to Na+.
D. decreasing its membrane's permeability to Cl-.

increasing its membrane's permeability to K+.

Saltatory conduction is a term applied to
A. an action potential that skips the axon hillock in moving from the dendritic region to the axon terminal.
B. rapid movement of an action potential reverberating back and for the along a neuron.
C. jumping from one node of Ranvier to the next in a myelinated neuron.
D. jumping from one neuron to an adjacent neuron.

jumping from one node of Ranvier to the next in a myelinated neuron.

When several EPSPs arrive at the axon hillock from different dendritic locations, depolarizing the postsynaptic cell to threshold for an action potential, this is an example of
A. the refractory state.
B. tetanus.
C. spatial summation.
D. temporal summation.

spatial summation

Neurons
A. have a uniform shape throughout the nervous system.
B. are more numerous than glial cells in the nervous system.
C. are found in mammals and birds only.
D. communicate with other cells at synapses.

communicate with other cells at synapses.

The resting potential of a neuron is produced by
A. voltage-gated channels in the membrane.
B. chemically gated channels in the membrane.
C. potassium channels in the membrane that are permanently open.
D. the concentration difference in Na+ across the membrane.

potassium channels in the membrane that are permanently open.

You find yourself standing next to a beautiful rosebush. Based on the current evolutionary data, which of the following do you and the rose have in common?
A. You both are multicellular.
B. You both lack a membrane-bound nucleus.
C. You are both prokaryotic.
D. You and the rose have nothing in common.

You both are multicellular.

Which of the following statements is false?
A. Darwin's theory of evolution by natural selection was influenced by his experiences as a pigeon breeder.
B. Individuals evolve according to Darwin's theory.
C. Death rates in nature are usually high.
D. Offspring tend to resemble their parents.

Individuals evolve according to Darwin's theory.

Convergent evolution occurs when two species living in
A. the same area becomes reproductively isolated.
B. different areas become reestablished and are able to reproduce.
C. the same area are competing for the same resource thus causing one to evolve away from the other.
D. different areas evolve similarities through natural selection acting on those characteristics.

different areas evolve similarities through natural selection acting on those characteristics