Because you want to be as prepared as possible for Biology 110, you want to find out if this weeks' recitation will include a quiz or discussion. The best course of action is to:

a. get that info by emailing Melissa

b. consult page x of the Read Me First Document

c. email Dr. Bos or ask him after class

d. email Dr. Browning - he's a wealth of knowledge

e. Just cowboy up and go to recitation. There is no way to find out that information ahead of time

b. consult page x (roman numeral 10) of the Read Me First Document

In comparing two atoms, you discover that atom #1 has 13 protons and a mass of 26. Atom #2 has 13 protons and a mass of 27. From this you can reasonably conclude:

a. The two atoms are isotopes of the same element

b. Atom #2 is a radioisotope of atom #1

c. Atom #2 carries a charge

d. The two atoms are different elements

e. These atoms will likely form ions by gaining electrons to fill their outer shell

Chemical reactivity is best predicted by:

a. the isotopes of that element

b. the charge of the protons in the nucleus

c. electrons closest to the nucleus

d. the number of neutrons in the energy shells

e. the filling of outer energy shells

Carbon (4 electrons in outer shell)-nitrogen(3 electrons in outer shell) (CN) compounds are common in biochemistry and bonded through

a. ionic bonds, formed by nitrogen gaining the valence electrons from carbon

b. nonpolar covalent bonds

c. polar covalent bonds with carbon having a partial negative charge

d. polar covalent bonds with nitrogen having a partial negative charge

e. hydrophobic interactions because of the equal sharing of electrons

A liquid solution with a hydrogen ion (H+) concentration of 10^-9 is

a. acidic, with a pH of 9

b. neutral

c. basic, with a pH of 10

d. basic, with a pH of 9

e. acidic, with a pH of 10

When adding another acid (for example, HCl) to weak acid solution, you expect the weak acid to

a. accept more protons (H+ ions), lowering the pH dramatically

b. accept more protons, raising the pH dramatically

c. accept more protons, keeping the pH relatively unchanged

d. accept more protons, behaving like an acid

e. donate more protons, behaving like an acid

The properties of water

a. include high heat of vaporization and surface tension, and are due to hydrophobic interactions between water molecules

b. include cohesion and high specific heat, and are due to hydrogen bonding of water molecules

c. make nonpolar compounds soluble in water

d. make it impossible to dissolve ionic solids

e. are due to the partial positive charge of oxygen and the partial negative charge of hydrogen

The four classes of macromolecules

a. are made from the same monomers

b. cannot be broken down into individual subunits

c. are assembled by the process of condensation

d. are soluble in water

e. are assembled because equilibrium favors synthesis

Glucose is used to make the following three molecules:

a.  proteins, nucleic acids, and carbohydrates

b. sucrose, maltose, and lactose

c. Glycerol, fatty acids, and phosphate

d. Glycerol, starch, and cellulose

e. fructose, galactose, and glyceraldehyde

Examination of a short polypeptide reveals that all of the monomers contain carbon ring or methyl (-CH3) R groups. Therefore, the polypeptide is:

a. hydrophobic

b. acidic

c. soluble in water

d. charged

e. polar

The sequence of amino acids in a protein includes all possible amino acids but the protein is made of a single polypeptide. With this information, how would you characterize this protein?

a. high secondary structual diversity, and low tertiary structural diversity

b. high tertiary and quaternary structural diversity

c. acidic due to the many amino acids

d. a transmembrane protein due to hydrophobic amino acids

e. high primary structural diversity, and lacking quaternary structural diversity

A nucleic acid polymer that is not in the nucleus is most likely:

a. RNA

b. DNA

c. nucleotides

d. double stranded

e. found in the nucleolus

What is a characteristic that all lipids share, at least in part?

a. similar monomers

b. formation of hydrogen bonds

c. fatty acid chains

d. functioning as an energy storage molecule

e. nonpolarity

What best describes the dominant property of a pure phospholipid membrane?

a. acidic

b. basic

c. saturated

d. hydrophobic

e. hydrophilic

What information can you gain by comparing the surface area of a monolayer of phospholipids with the surface area of the cells from which those phospholipids came?

a. surface area to volume ratio of the cells

b. the size of the cells

c. how saturated the fatty acids of the phospholipids are

d. how many layers of phospholipids the membrane has

e. how many proteins are in the cell membrane

Which of the following molecules would most easily be able to pass through a pure phospholipid membrane?

a. amino acids

b. DNA

c. Glycogen

d. NA+ (sodium ion)

e. O2 (gaseous oxygen)

A medical doctor reports having patients with "leaky" blood vessels, where fluid is able to escape by passing between cells of the blood vessels. In consultation with Biol 110 students, the good doctor learns that this is probably due to a problem with:

a. tight junctions

b. desmosomes

c. gap junctions

d. plasmodesmata

e. anchoring junctions

After a cold night, a single-celled paramecium living in a cattle pond moves to a warm, sunny spot to feed in. In response to this movment, the paramecium will most efficiently adjust its cell membranes by:

a. including longer and more unsaturated fatty acids in membrane phospholipids

b. include shorter and more unsaturated fatty acids in membrane phospholipids

c. include longer and more saturated fatty acids in membrane phospholipids

d. include shorter and more saturated fatty acids in membrane phospholipids

e. applyling SPF 45 sunscreen

The kinetics of transport by faciliated diffusion indicate that even though you keep increasing the concentration of an ion, the rate of movement is constant, and does not increase. You conclude that the ion is moving into the cell by:

a. simple diffusion

b. a carrier protein

c. active transport

d. a channel protein

e. an antiporter

A membrane protein transports calcium ions into a cell only when there is a high concentration of those ions outside of the cell. That same protein causes sodium ions to accumulate to a high concentration outside of the cell, being transported from the inside. These ions are being moved by:

a. faciliated diffusion using a channel protein

b. simple diffusion

c. coupled transport using an antiporter

d. coupled transport using a symporter

e. an ATP-driven uniporter

Active transport of molecules across a cell membrane requires

a. a channel protein and ATP

b. ATP or coupled transport for energy

c. a carrier or channel protein

d. a concentration gradient

e. an isotonic solution

Placing a cell in hypotonic solution will cause water to:

a. move out of the cell by osmosis

b. move into the cell by osmosis

c. have no net movement

d. move into the cell by active transport

e. move out of the cell by active transport

When large amounts of cholesterol are needed by a cell, the likely mechanism of transport will be:

a. endocytosis

b. active transport

c. facilitated diffusion

d. simple diffusion

e. exocytosis

A certain cell's function is to synthesize and secrete a protein. In direct connection with its function, that cell will likely have

a. an extensive smooth ER

b. many mitochondria

c. numberous cytoplasmic ribosomes

d. many lysosomes

e. an extensive rough ER

What is the universal organelle?

a. nucleus

b. mitochondra

c. golgi

d. ribosomes

e. lysosomes

Which of the following organelles are involved in manufacture and trafficking of a protein destined to be exported from the cell?

a. smooth ER, rough ER, transport vesicles, Golgi

b. rough ER, transport vesicle, golgi, secretory vesicle

c. rough ER, lysosome, golgi, secretory vesicle

d. cytoplasmic ribosome, smooth ER, transport vesicle, golgi

e. cytoplasmic ribosome, rough ER, transport vesicle, golgi

Mitochondria, chloroplasts, and the nucleus all have what in common?

a. nuclear pores

b. Cristae

c. a double layer membrane

d. grana

e. similar function

A protein that needs modification prior to proper functioning will undergo those modifications in the:

a. smooth ER and rough ER

b. rough ER and golgi

c. smooth ER and golgi

d. golgi and the transport vesicle

e. rough ER and lysosome

Despite the fact that eukaryotic cells share many features, the following are only found in plant cells, not animal cells:

a. chloroplasts, plastides, and a cell wall

b. mitochondria, plastids, and vacuoles

c. lysosomes, desmosomes, and plasmodesmata

d. vacuoles, nucleolus, cholorplasts

e. plasmodesmata, vacuoles, and nuclear pores

Intermediate filaments are characterized as

a. unbranched, dynamic and involved in cell movement

b. unbranched, dynamic and involved in movement within the cell

c. branched dynamic fibers involved in cell movement

d. being closely associated with motor proteins like dynein and mysoin

e. branched, stable fibers that provide structure to the cell

Cells in a localized area are able to rapidly respond to growth factor signaling molecules because of:

a. ribosomes

b. the extra cellular matrix

c. nuclear pores

d. endocytosis

e. channel proteins

In an energetically closed system at a constant termperature, the reversible reaction, xy ↔ zw occurs. If the G (free energy) = 12 in xy and G = 6 in zw, then:

a. xy→zw will occur spontaneously

b. xy←zw will occur spontaneously

c. xy↔zw will increase enthalpy in the system

d. xy←zw will increase entropy in the system

e. xy→zw will increase the free energy in the system

If the results of an experiment indicate that before adding an enzyme, the ΔG of a reaction is 4.6, but after adding an enzyme, the ΔG=-2.1, then:

a. the activation energy has been lowered

b. these data indicate an increase in the rate of the reaction

c. the enzyme binds more than one type of substrate

d. the reaction did not eneed an enzyme to proceed in the first place

e. the data are falsified; no such change can take place with an enzyme

The molecule and reaction most often coupled to endergonic reactions is:

a. ATP → ADP + Pi

b. ADP → ATP + Pi

c. NADPh → NADP+ + H+

d. ADP + Pi → ATP

e. NAD+ + H+ → NADH

Arranging electron carriers according to increasing affinity for electrons

a. catalyzes the oxidation of water by photosystem II

b. creates an electron transport chain

c. allows energy to be released in one large, efficient step

d. prevents redox reactions from occuring

e. allows a braod absorbance spectrum in plants

During photosynthesis, O2 is produced from the

a. oxidation of CO2

b. reduction of CO2

c. reduction of H2O

d. oxidation of H2O

e. oxidation of C6H12O6 (simple sugars)

In photosynthesis, ATP is directly produced via

a. chemiosmosis

b. substrate-level phosphorylation

c. the Calvin cycle

d. photosystem I

e. NADPH oxidation

If a plant cell lacks the energy to synthesize ATP during photosynthesis, what is the most likely direct cause of this problem?

a. ATP synthase

b. the B6f complex

c. NADPH

d. Clyceraldehyde-3-phosphate (G3P)

 e. photosystem I

During the light reactions, electrons flow

a. from photosystem I to photosystem II

b. from ATP to ADP

c. from NADPH to NAHP+

d. from water to NADPH

e. from water to carbon dioxide

Where do the reactions of the Calvin cycle take place?

a. thylakoid disk compartment

b. stroma

c. thylakoid membrane

d. the antenna complex

e. the B6f complex

If the Calvin cycle stops because there are no electrons to drive the reduction of carbons, what is the most likely cause?

a. the thylakoid membrane is not intact

b. RuBP has not been regenerated

c. we have not completed the 6 reactions required to complete the cycle

d. there is a failure in the B6f complex

e. photosystem I is not functioning properly

If the Calvin cycle procedds normally until failure of the carbon reduction reactions, but there are electrons to drive that reaction, what is the most likely cause?

a. insufficient NADPH

b. insufficient ATP

c. insufficient RuBP

d. insufficient sunlight

e. insufficient sources of inorganic carbon

How many times have the reactions of the Calvin cycle been complete if we have produced twelve G3P molecules?

a. one

b. two

c. four

d. six

e. twelve

What is the main function of chlorophyll molecules in photosynthesis?

a. oxidize water

b. reduce carbon dioxide

c. act as a proton pump

d. absorb and transfer light energy

e. catalyze the reactions of ATP synthesis

What is the source of energy for the active transport of protons in the light reactions?

a. the flow of electrons along an electron transport chain

b. ATP hydrolysis

c. Glucose metabolism

d. coupled transport

e. reduction of NADP+

What is the main organelle involved in photosynthesis?

a. mitochondria

b. chloroplasts

c. nucleus

d. ribosomes

e. stroma

What is the direct product of the Calvin cycle?

a. 3-PGA

b. Glucose

c. CO2

d. G3P

e. ATP

What is the general relationship between the energy and metabolic reactions?

a. anabolic reactions build & and are endergonic, catabolic reactions break down & are exergonic

b. anabolic reactions break down & and are endergonic, catabolic reactions build up & are exergonic

c. anabolic reactions build & and are exergonic, catabolic reactions break down & are endergonic

d. anabolic reactions break down & and are exergonic, catabolic reactions build up & are endergonic

e. anabolid reactions create energy; catabolic reactions change energy forms

What three processes are incluced in cellular respiration?

a. carbon fixation, reduction of carbon, and regeneration

b. priming reaction, splitting of glucose, oxidation of pyruvate

c.  oxidation ofpyruvate, krebs cycle, chemiosmosis

d. krebs cycle, carbon fixation, chemiosmosis

e. oxidation of pyruvate, glycolysis, chemiosmosis

What is a main difference between substrate-level phosphorylation and oxidative phosphorylation?

a. substrate-level phosphorylation only occurs in the cytoplasm

b. substrate-level phosphorylation uses organic phophate, oxidative phosphorylation uses inorganic phosphate

c. substrate-level phosphorylation produce ATP, oxidative phosphorlyation produces ADP

d. substrate-level phosphorylation uses NADP+, oxidative phosphorylation uses ATP

e. substrate-level phosphorylation is endergonic, oxidative phosphorylation is exergonic

What is the mechanism and process responsible for ATP produce in the cytoplasm?

a. oxidative phosphorylation/glycolysis

b. substrate-level-phosphorylation/oxidation of pyruvate

c.  oxidative phosphorylation/ krebs cycle

d. substrate-level phosphorylation/ krebs cycle

e. substrate-level phosphorylation/ glycolysis

What is the end product of glycolysis?

a. pryuvate

b. an acetyl molecule

c. ethanol

d. CO2

e. acetaldehyde

What is the net energy yield of glycoysis (total output after subtracting energy used in the priming reaction)?

a. 2 ATP

b. 2 NADH

c. 1 ATP; 1 NADH

d. 2 ATP; 1 NADH

e. 2 ATP; 2 NADH

e. 2 ATP; 2 NADH

You are presented with an unknown vegetable oil at room temperature and asked to characterize it in a lab. Without experimentation you already know that:

a. it is unsaturated and contains some carbon-carbon double bonds

b. it contains three fatty acid chains

c. it contains two fatty acid chains

d. is is saturated and contains some carbon-carbon double bonds

e. is is unsaturated and does not contain carbon-carbon double bonds

What is the difference between the fermentation of ethanol and fermentation of lactate (lactic acid)?

a. one is an oxidation reaction the other is a reduction reaction

b. the production of ATP

c. the regeneration of NAD+

d. the removal of CO2

e. the electron donor is different

Fermentation and cellular respiration accomplish what important task that enables continual glycolysis?

a. oxidation of NADH

b. reduction of NADH

c. oxidation of FADH2

d. regeneration of the Krebs cycle starting materials

e. the synthesis of organic sugars

Which of the following processes does not include a redox reaction?

a. oxidation of pyruvate

b. fermentation

c. calvin cycle

d. oxidative phosphorylation

e. substrate-level phosphorylation

e. substrate-level phosphorylation

What step in the oxidation of glucose is directly responsible for the majority of ATP production?

a. oxidation of pyruvate

b. chemiosmosis

c. glycolysis

d. fermentation

e. Krebs cycle

The process of providing energy through the facilitated diffusion of protons to drive the endergonic synthesis of ATP is named:

a. chemiosmosis

b. substrate-level phosphorylation

c. redox reactions

d. fermentation

e. glycolysis

If the mitochondrial membrane were not intact, what process would be most adversely affected?

a. glycolysis

b. the calvin cycle

c. chemiosmosis

d. the krebs cycle

e. substrate-level phosphorylation

Which process completes the oxidation of glucose?

a. glycolysis

b. chemiosmosis

c. krebs cycle

d. oxidative phosphorylation

e. calvin cycle

Which molecule donates electrons to the second member of the electron transport chain of the mitochondria?

a. ATP

b. NADH

c. NADPH

d. FADH2

e. Acetyl-CoA

Electron transport chain members in the mitochondrea pumps protons into the:

a. stroma

b. mitochondrial matrix

c. intermembrane space

d. cytoplasm

e. thylakoid disk space

If an animal cell lacks oxygen, what is the first process likely to be adversly affected?

a. the electron transport chain

b. the krebs cycle

c. the oxidation of pyruvate

d. glycolysis

e. fermentation

During which two stages of the oxidation of glucose is CO2 produced?

a. krebs cycle; chemiosmosis

b. glycolysis; krebs cycle

c. glycolysis; oxidation of pyruvate

d. glycolysis; chemiosmosis

e. krebs cycle; oxidation of pyruvate

e. krebs cycle; oxidation of pyruvate

A cell that is lacking the ability to synthesize cholesterol and membrane lipids probably has a problem with its:

a. mitochondria

b. golgi

c. smooth ER

d. rough ER

e. transport vesicles

Heterotrophs are dependent on autotrophs for what two important products?

A. energy and organic matter

B. food and water

C. free energy and entropy

D. decomposition and incorporation of organic matter

E. football tickets and movie tickets

Why is the sun so important to all living organisms?

A. without it, we have no energy input in biology and entropy would dominate, creating disorder

B. without it, energy would not be able to cycle through reservoirs in the ecosystem

C. the sun is not important, as evidenced by the fact that so little of the sun's energy is captured by biological systems

D. without the sun we would be unable to emit thermal energy into space

E. withouth the sun's energy, heterotrophs would not be able to capture and transfer energy in biological systems

Where does an organism that is at the first trophic level get its energy?

A. from trophic level 0 and 2

B. from eating herbivores

C. from eating primary consumers

D. from the sun

E. from eating plant matter

Detritovores, such as decomposing bacteria, obtain matter and energy from which trophic level(s)?

A. trophic level 1

B. trophic level 2

C. trophic levels 1 and 2

D. trophic levels 1-3

E. all trophic levels

E. all trophic levels

What is the main source and the chemical forms of bioavailable nitrogen?

A. nitrogen fixation; NH3 and NO3

B. nitrogen fixation; N2 and NH3

C. nitrogen recycling; N2 and NH3

D. nitrogen recycling; NH3 and NO3

E. nitrogen recycling; NO3 and N2

What is an easy way to disrupt the water cycle in terrestrial ecosystems and why?

A. remove detritovores - they break down water molecules to purify them

B. remove the fungi - they provide essential elements that are delivered by water to plants

C. remove trees - they provide transpiration, which brings about precipitation

D. remove the nitrogen fixing bacteria - they provide the nitrates necessary for the splitting of water in photosynthesis

E. remove the nitrifying bacteria - they provide ammonia necessary for the splitting of water in photosynthesis

An individual believes that a forest of fir tress has a certain dollar value because that is how much the lumber for those trees is worth. Is this an accurate value of the forest? Why or why not?

A. yes - the value of any part of the ecosystem is what it can be sold for at the appropriate market

B. yes - this represents the true value of that forest ecosystem in terms of benfits to mankind

C. no - this does not account for the production that is gained by converting the forest land to agriculture

D. no - the tre value of the ecosystem must account for all services and products provided by that ecosystem, not just those that can be sold at market

E. no - the value does not account for the cost incurred to re-plant the forest

What may be the likely result to damage to any one part of an ecosystem?

A. the ability to perform life-sustaining services will be decreased because the interconnectedness of the ecosystem will be diminished

B. ecosystems are highly interconnected, so damage to just one part will have no effect on ecosystem functioning

C. all parts of an ecosystems can be easily restored in a short amount of time, so effects will be short term

D. the flow of energy in a system may be reversed

E. trophic level energy transfer efficiency will increase to 25%

What limits the number of trophic levels in an ecosystem?

A. the number of carnivores in the ecosystems

B. the number of detritovores available for decomposition

C. the amount of water in an ecosystem

D. the reproductive rate of lower trophic levels

E. the large amount of energy lost at each trophic level

E. the large amount of energy lost at each trophic level

The only population of a species is decimated by disease, leaving a small number of individuals. Which of the following can we safely assume is a major force affecting allele fequencies in this population?

A. genetic dominance

B. genetic drift

C. migration

D. mutation

E. nonrandom mating

In a diploid population of 100 individuals, 20 copies of allele A are present. What is the frequency of allele A?

A. 2%

B. 5%

C. 10%

D. 20%

E. 40%

What is one reason why genotype and phenotype might not perfectly correspond?

A. allelic dominance

B. genetic drift

C. population size

D. migration

E. population growth

Esponential growth rates are influenced by:

A. K

B. K-N/K

C. N(K-N/K)r

D. rN

E. dN/dT

Which of the following factors does not contribute to carrying capacity?

A. availability of food

B. build up of waste

C. competition

D. allelic dominance

E. disease

How many genotypes are possible in diploid organism for a gene with two alleles?

A. 1

B. 2

C. 3

D. 4

E. 6

Which of the following ideas associated with evolution has not been observed in nature?

A. descent with modification

B. differential reproduction

C. inheritance of acquired characteristics

D. variation in a population

E. excess reproduction

Which evolutionary phenomenon is most closely tied to fitness?

A. survival

B. reproduction

C. the condition of the animal

D. size

E. surviving the Spanish flu epidemic

Which two brances of science are unified in the modern synthesis?

A. disruptive selection and directional selection

B. artificial selection and natural selection

C. genetics and evolution

D. religion and natural selection

E. natural selection and inheritance of acquired characteristics

If in a natural population where the animals have a variety of coat colors, those with the darkest coat color and the lightest coat color are the most reproductively successful, what type of selection is occuring?

A. directional selection

B. disruptive selection

C. stabilizing selection

D. artificial selection

E. a first-round draft selection

What is the process whereby a bacterium acqures antibiotic resistance by obtaining DNA from another bacterium that is already resistant?

A. graduation

B. matriculation

C. conjugation

D. transformation

E. mutation

A gene with only a single allele cannot evolve by natural selection because:

A. genetic loci don't reproduce - the organisms that carry them do

B. no variation exists

C. genetic loci don't suffer mortaility and die

D. geneitc variation isn't inheritable and can't be passed on to offspring

E. genetic loci never experience beneficial mutations

At a party someone presents an argument against evolution based on the probabilities of complex structures arising. Most people are surprised to find that a mathematician who knows nothing of evolution rejects this argument entirely. This mathematician can do this because:

A. evolution, unlike other scientific ideas, is just a theory

B. probabilities can't be applied to events that have already occured

C. natural selection probabilities are increased because it works through the accumulation of small changes

D. mathematicians are odd characters - they reject ideas at random

E. evolution is based on random mutations and one cannot calculate the probabilities of random mutations

The venom of a wild population of snakes paralyzes their only food source in an average of 97 seconds. Twenty generations later, the descendents of the original population now paralyzes their food in an average of 92 seconds. This is most likely an example of:

A. genetic drift

B. inheritance of acquired characteristics

C. artificial selection

D. migration

E. descent with modification

E. descent with modification

Attacking evolution because it imposes on religious beliefs is unfounded because

A. religious beliefs of supernatual phenomena are immune from attacks by science because science is restricted to the natual world

B. evolution is just a theory anyway, so it is of no consequence

C. evolution and the origin of life are the same things and since we don't know anything about the origin of life, we dont' know anything about evolution

D. evolution is a new idea in science and has yet to be proven

E. scientists and philosophers have shown that evolution ceased to exist around 1066

Two individuals are considered different species according to the biological species concept when what conditions are met?

A. they are on different branches of a phylogenetic tree

B. they are geographically separated

C. they have established reproductive isolation

D. they are no longer similar in appearance

E. they have estabilished different allele frequencies

Two organisms occur in the same area but occupy different habitats and so rarely encounter one another. This is an example of what type of reproductive isolating mechanism?

A. temporal isolation

B. ecological isolation

C. behavior isolation

D. mechanical isolation

E. geographical isolation

The colonization of a remote area by a few individuals and the subsequent speciation between the colonists and the source population is an example of what type of speciation?

A. allopatric

B. sympatric

C. instntaneous

D. genetic drift

E. founder effect

Plants commonly achieve speciation through what type of reproductive isolation that is rare in animals?

A. behavioral isolation

B. geographic isolation

C. ecological isolation

D. temporal isolation

E. polyploidy

E. polyploidy

Sharp declines in biodiversity are due to what?

A. unexploited ecological niches

B. nonrandom mating

C. speciation

D. extinction

E. predation

A fossil that has some structures that resemble older, more primitive organisms and some that resemble more advanced organisms is

A. a dinosaur

B. homologous

C. analogous

D. a transitional form

E. a new species according to the biological species concept

Scientific theories remain theories because they can never be proven true in all cases. This is because science often proceeds by what type of reasoning?

A. induction

B. deduction

C. metaphysical

D. supernatural

E. physical

What is the science of recovering the ancestor-descendant relationships among species?

A. phylogenetics

B. systematics

C. speciation

D. species interaction

E. paleontology

Structures on two different species appear very different in shape and function, but have been shown to be inherited from a common ancestor. This structure must be:

A. allopatric

B. sympatric

C. homologous

D. analogous

E. the target of genetic drift