Which of the following represents an idea that Darwin learned from the writings of Thomas Malthus?
A) Technological innovation in agricultural practices will permit exponential growth of the human population into the foreseeable future.
B) Populations tend to increase at a faster rate than their food supply normally allows.
C) Earth changed over the years through a series of catastrophic upheavals.
D) The environment is responsible for natural selection.
E) Earth is more than 10,000 years old.

Answer: B

Given a population that contains genetic variation, what is the correct sequence of the following events, under the influence of natural selection?
1. Well-adapted individuals leave more offspring than do poorly adapted individuals.
2. A change occurs in the environment.
3. Genetic frequencies within the population change.
4. Poorly adapted individuals have decreased survivorship.

A) 2 → 4 → 1 → 3
B) 4 → 2 → 1 → 3
C) 4 → 1 → 2 → 3
D) 4 → 2 → 3 → 1
E) 2 → 4 → 3 → 1

Answer: A

Which of the following must exist in a population before natural selection can act upon that population?
A) genetic variation among individuals
B) variation among individuals caused by environmental factors
C) sexual reproduction
D) Three of the responses are correct.
E) Two of the responses are correct.

Answer: A

Which of Darwin's ideas had the strongest connection to Darwin having read Malthus's essay on human population growth?
A) descent with modification
B) variation among individuals in a population
C) struggle for existence
D) the ability of related species to be conceptualized in "tree thinking"
E) that the ancestors of the Galápagos finches had come from the South American mainland

Answer: C

Of the following anatomical structures, which is homologous to the bones in the wing of a bird?
A) cartilage in the dorsal fin of a shark
B) bones in the hind limb of a kangaroo
C) chitinous struts in the wing of a butterfly
D) bony rays in the tail fin of a flying fish
E) bones in the flipper of a whale

Answer: E

If two modern organisms are distantly related in an evolutionary sense, then one should expect that
A) they live in very different habitats.
B) they should share fewer homologous structures than two more closely related organisms.
C) their chromosomes should be very similar.
D) they shared a common ancestor relatively recently.
E) they should be members of the same genus.

Answer: B

Structures as different as human arms, bat wings, and dolphin flippers contain many of the same bones, these bones having developed from very similar embryonic tissues. How do biologists interpret these similarities?
A) by identifying the bones as being homologous structures
B) by the principle of convergent evolution
C) by proposing that humans, bats, and dolphins share a common ancestor
D) Three of the statements above are correct.
E) Two of the statements above are correct.

Answer: E

Which of the following pieces of evidence most strongly supports the common origin of all life on Earth?
A) All organisms require energy.
B) All organisms use essentially the same genetic code.
C) All organisms reproduce.
D) All organisms show heritable variation.
E) All organisms have undergone evolution.

Answer: B

During an individual organism's lifetime, which of these is most likely to help the organism respond properly to changes in its environment?
A) microevolution
B) change in allele or gene frequency
C) change in gene expression
D) change in average heterozygosity

Answer: C

Which of these variables is likely to undergo the largest change in value as the result of a mutation that introduces a brand-new allele into a population's gene pool at a locus that had formerly been fixed?
A) average heterozygosity
B) nucleotide variability
C) geographic variability
D) average number of loci

Answer: A

Although each of the following has a better chance of influencing gene frequencies in small populations than in large populations, which one most consistently requires a small population as a precondition for its occurrence?
A) mutation
B) nonrandom mating
C) genetic drift
D) natural selection
E) gene flow

Answer: C

In modern terminology, diversity is understood to be a result of genetic variation. Which of the following is a recognized source of variation for evolution?
A) mistakes in translation of structural genes
B) mistakes in protein folding
C) rampant changes to the dictionary of the genetic code
D) binary fission
E) recombination by crossing over in meiosis

Answer: E

Which statement about variation is true?
A) All phenotypic variation is the result of genotypic variation.
B) All genetic variation produces phenotypic variation.
C) All nucleotide variability results in neutral variation.
D) All new alleles are the result of nucleotide variability.
E) All geographic variation results from the existence of clines.

Answer: D

In the formula for determining a population's genotype frequencies, the 2 in the term 2pq is necessary because
A) the population is diploid.
B) heterozygotes can come about in two ways.
C) the population is doubling in number.
D) heterozygotes have two alleles.

Answer: B

In the formula for determining a population’s genotype frequencies, the pq in the term 2pq is necessary because
A) the population is diploid.
B) heterozygotes can come about in two ways.
C) the population is doubling in number.
D) heterozygotes have two alleles.

Answer: D

Hardy-Weinberg equilibrium must occur in populations wherein
A) an allele remains fixed.
B) no genetic variation exists.
C) natural selection is not operating.
D) All three of the responses above are correct.
E) Only two of the responses above are correct.

Answer: E

Evolution
A) must happen, due to organisms’ innate desire to survive.
B) must happen whenever a population is not well-adapted to its environment.
C) can happen whenever any of the conditions for Hardy-Weinberg equilibrium are not met.
D) requires the operation of natural selection.
E) requires that populations become better suited to their environments.

Answer: C

What is true of natural selection?
A) Natural selection is a random process.
B) Natural selection creates beneficial mutations.
C) The only way to eliminate harmful mutations is through natural selection.
D) Mutations occur at random; natural selection can preserve and distribute beneficial mutations.
E) Mutations occur when directed by the good of the species; natural selection edits out harmful mutations and causes populations to adapt to the beneficial mutations.

Answer: D

Natural selection changes allele frequencies because some ________ survive and reproduce more successfully than others.
A) alleles
B) loci
C) gene pools
D) species
E) individuals

Answer: E

What is true of macroevolution?
A) It is the same as microevolution, but includes the origin of new species.
B) It is evolution above the species level.
C) It is defined as the evolution of microscopic organisms into organisms that can be seen with the naked eye.
D) It is defined as a change in allele or gene frequency over the course of many generations.
E) It is the conceptual link between irritability and adaptation.

Answer: B

Which of the following statements about species, as defined by the biological species concept, is (are) correct?
I. Biological species are defined by reproductive isolation.
II. Biological species are the model used for grouping extinct forms of life.
III. The biological species is the largest unit of population in which successful interbreeding is possible.
A) I and II
B) I and III
C) II and III
D) I, II, and III

Answer: B

Which of the various species concepts distinguishes two species based on the degree of genetic exchange between their gene pools?
A) phylogenetic
B) ecological
C) biological
D) morphological

Answer: C

There is still some controversy among biologists about whether Neanderthals should be placed within the same species as modern humans or into a separate species of their own. Most DNA sequence data analyzed so far indicate that there was probably little or no gene flow between Neanderthals and Homo sapiens. Which species concept is most applicable in this example?
A) phylogenetic
B) ecological
C) morphological
D) biological

Answer: D

You are confronted with a box of preserved grasshoppers of various species that are new to science and have not been described. Your assignment is to separate them into species. There is no accompanying information as to where or when they were collected. Which species concept will you have to use?
A) biological
B) phylogenetic
C) ecological
D) morphological

Answer: D

Dog breeders maintain the purity of breeds by keeping dogs of different breeds apart when they are fertile. This kind of isolation is most similar to which of the following reproductive isolating mechanisms?
A) reduced hybrid fertility
B) hybrid breakdown
C) mechanical isolation
D) habitat isolation
E) gametic isolation

Answer: D

What does the biological species concept use as the primary criterion for determining species boundaries?
A) geographic isolation
B) niche differences
C) gene flow
D) morphological similarity
E) molecular (DNA, RNA, protein) similarity

Answer: C

The difference between geographic isolation and habitat differentiation is the
A) relative locations of two populations as speciation occurs.
B) speed (tempo) at which two populations undergo speciation.
C) amount of genetic variation that occurs among two gene pools as speciation occurs.
D) identity of the phylogenetic kingdom or domain in which these phenomena occur.
E) the ploidy of the two populations as speciation occurs.

Answer: A

Among known plant species, which of these have been the two most commonly occurring phenomena that have led to the origin of new species?

1. allopatric speciation
2. sympatric speciation
3. sexual selection
4. polyploidy

A) 1 and 3
B) 1 and 4
C) 2 and 3
D) 2 and 4

Answer: D

According to the concept of punctuated equilibrium, the "sudden" appearance of a new species in the fossil record means that
A) the species is now extinct.
B) speciation occurred instantaneously.
C) speciation occurred in one generation.
D) speciation occurred rapidly in geologic time.
E) the species will consequently have a relatively short existence, compared with other species.

Answer: D

According to the concept of punctuated equilibrium,
A) natural selection is unimportant as a mechanism of evolution.
B) given enough time, most existing species will branch gradually into new species.
C) a new species accumulates most of its unique features as it comes into existence.
D) evolution of new species features long periods during which changes are occurring, interspersed with short periods of equilibrium, or stasis.
E) transitional fossils, intermediate between newer species and their parent species, should be abundant.

Answer: C

Speciation
A) occurs at such a slow pace that no one has ever observed the emergence of new species.
B) occurs only by the accumulation of genetic change over vast expanses of time.
C) must begin with the geographic isolation of a small, frontier population.
D) and microevolution are synonymous.
E) can involve changes to a single gene.

Answer: E

Which of the following statements about speciation is correct?
A) The goal of natural selection is speciation.
B) When reunited, two allopatric populations will interbreed freely if speciation has occurred.
C) Natural selection chooses the reproductive barriers for populations.
D) Prezygotic reproductive barriers usually evolve before postzygotic barriers.
E) Speciation is a basis for understanding macroevolution.

Answer: E

In order for speciation to occur, what must be true?
A) The number of chromosomes in the gene pool must change.
B) Changes to centromere location or chromosome size must occur within the gene pool.
C) Large numbers of genes that affect a single phenotypic trait must change.
D) Large numbers of genes that affect numerous phenotypic traits must change.
E) At least one gene, affecting at least one phenotypic trait, must change.

Answer: E

In a hypothetical situation, a certain species of flea feeds only on pronghorn antelopes. In rangelands of the western United States, pronghorns and cattle often associate with one another. If some of these fleas develop a strong preference for cattle blood and mate only with other fleas that prefer cattle blood, then over time which of these should occur, if the host mammal can be considered as the fleas' habitat?

1. reproductive isolation
2. sympatric speciation
3. habitat isolation
4. prezygotic barriers

A) 1 only
B) 2 and 3
C) 1, 2, and 3
D) 2, 3, and 4
E) 1 through 4

Answer: E

The most likely explanation for the high rate of sympatric speciation that apparently existed among the cichlids of Lake Victoria in the past is
A) sexual selection.
B) habitat differentiation.
C) polyploidy.
D) pollution.
E) introduction of a new predator.

Answer: A

How were conditions on the early Earth of more than 3 billion years ago different from those on today's Earth?
A) Only early Earth was intensely bombarded by large space debris.
B) Only early Earth had an oxidizing atmosphere.
C) Less ultraviolet radiation penetrated early Earth's atmosphere.
D) Early Earth's atmosphere had significant quantities of ozone.

Answer: A

What is true of the amino acids that might have been delivered to Earth within carbonaceous chondrites?
A) They had the same proportion of L and D isomers as Earth does today.
B) Their abundance would have been dramatically reduced upon passage through early Earth's oxidizing atmosphere.
C) There were more kinds of amino acids on the chondrites than are found in living organisms today.
D) They were delivered in the form of polypeptides.

Answer: C

Which of the following is the correct sequence of events in the origin of life?

I. formation of protobionts
II. synthesis of organic monomers
III. synthesis of organic polymers
IV. formation of DNA-based genetic systems

A) I, II, III, IV
B) I, III, II, IV
C) II, III, I, IV
D) II, III, IV, I

Answer: C

Which of the following is a defining characteristic that all protobionts had in common?
A) the ability to synthesize enzymes
B) a surrounding membrane or membrane-like structure
C) RNA genes
D) the ability to replicate RNA

Answer: B

The first genes on Earth were probably
A) DNA produced by reverse transcriptase from abiotically produced RNA.
B) DNA molecules whose information was transcribed to RNA and later translated in polypeptides.
C) auto-catalytic RNA molecules.
D) oligopeptides located within protobionts.

Answer: C

The synthesis of new DNA requires the prior existence of oligonucleotides to serve as primers. On Earth, these primers are small RNA molecules. This latter observation is evidence in support of the hypothesized existence of
A) a snowball Earth.
B) earlier genetic systems than those based on DNA.
C) the abiotic synthesis of organic monomers.
D) the delivery of organic matter to Earth by meteors and comets.
E) the endosymbiotic origin of mitochondria and chloroplasts.

Answer: B

Which measurement(s) would help determine absolute dates by radiometric means?
A) the accumulation of the daughter isotope
B) the loss of parent isotopes
C) the loss of daughter isotopes
D) Three of the responses above are correct.
E) Two of the responses above are correct.

Answer: E

Approximately how far back in time does the fossil record extend?
A) 3.5 million years
B) 5.0 million years
C) 3.5 billion years
D) 5.0 billion years

Answer: C

What is true of the fossil record of mammalian origins?
A) It is a good example of punctuated equilibrium.
B) It shows that mammals and birds evolved from the same kind of dinosaur.
C) It includes transitional forms with progressively specialized teeth.
D) It indicates that mammals and dinosaurs did not overlap in geologic time.
E) It includes a series that shows the gradual change of scales into fur.

Answer: C

An early consequence of the release of oxygen gas by plant and bacterial photosynthesis was to
A) generate intense lightning storms.
B) change the atmosphere from oxidizing to reducing.
C) make it easier to maintain reduced molecules.
D) cause iron in ocean water and terrestrial rocks to rust (oxidize).
E) prevent the formation of an ozone layer.

Answer: D

Which of the following statements provides the strongest evidence that prokaryotes evolved before eukaryotes?
A) Prokaryotic cells lack nuclei.
B) The meteorites that have struck Earth contain fossils only of prokaryotes.
C) Laboratory experiments have produced liposomes abiotically.
D) Liposomes closely resemble prokaryotic cells.
E) The oldest fossilized cells resemble prokaryotes.

Answer: E

What is true of the Cambrian explosion?
A) There are no fossils in geological strata that are older than the Cambrian explosion.
B) Only the fossils of microorganisms are found in geological strata older than the Cambrian explosion.
C) The Cambrian explosion is evidence for the instantaneous creation of life on Earth.
D) The Cambrian explosion marks the appearance of filter-feeding animals in the fossil record.
E) Recent evidence supports the contention that the Cambrian explosion may not have been as "explosive" as was once thought.

Answer: E

Fossilized stromatolites
A) all date from 2.7 billion years ago.
B) formed around deep-sea vents.
C) resemble structures formed by bacterial communities that are found today in some warm, shallow, salty bays.
D) provide evidence that plants moved onto land in the company of fungi around 500 million years ago.
E) contain the first undisputed fossils of eukaryotes and date from 2.1 billion years ago.

Answer: C

The oxygen revolution changed Earth's environment dramatically. Which of the following took advantage of the presence of free oxygen in the oceans and atmosphere?
A) the evolution of cellular respiration, which used oxygen to help harvest energy from organic molecules
B) the persistence of some animal groups in anaerobic habitats
C) the evolution of photosynthetic pigments that protected early algae from the corrosive effects of oxygen
D) the evolution of chloroplasts after early protists incorporated photosynthetic cyanobacteria
E) the evolution of multicellular eukaryotic colonies from communities of prokaryotes

Answer: A

If one organ is an exaptation of another organ, then what must be true of these two organs?
A) They are both vestigial organs.
B) They are both homologous organs.
C) They are undergoing convergent evolution.
D) They are found together in the same hybrid species.
E) They have the same function.

Answer: B

A swim bladder is a gas-filled sac that helps fish maintain buoyancy. The evolution of the swim bladder from lungs of an ancestral fish is an example of
A) an evolutionary trend.
B) exaptation.
C) changes in Hox gene expression.
D) paedomorphosis.
E) adaptive radiation.

Answer: B

Mycoplasmas are bacteria that lack cell walls. On the basis of this structural feature, which statement concerning mycoplasmas should be true?
A) They are gram-negative.
B) They are subject to lysis in hypotonic conditions.
C) They lack a cell membrane as well.
D) They should contain less cellulose than do bacteria that possess cell walls.
E) They possess typical prokaryotic flagella.

Answer: B

Though plants, fungi, and prokaryotes all have cell walls, we place them in different taxa. Which of these observations comes closest to explaining the basis for placing these organisms in different taxa, well before relevant data from molecular systematics became available?
A) Some closely resemble animals, which lack cell walls.
B) Their cell walls are composed of very different biochemicals.
C) Some have cell walls only for support.
D) Some have cell walls only for protection from herbivores.
E) Some have cell walls only to control osmotic balance.

Answer: B

Jams, jellies, preserves, honey, and other foodstuffs with high sugar content hardly ever become contaminated by bacteria, even when the food containers are left open at room temperature. This is because bacteria that encounter such an environment

A) undergo death by plasmolysis.
B) are unable to metabolize the glucose or fructose, and thus starve to death.
C) experience lysis.
D) are obligate anaerobes.
E) are unable to swim through these thick and viscous materials.

Answer: A

Which two structures play direct roles in permitting bacteria to adhere to each other, or to other surfaces?
1. capsules
2. endospores
3. fimbriae
4. plasmids
5. flagella

Answer: B

The typical prokaryotic flagellum features
A) an internal 9 + 2 pattern of microtubules.
B) an external covering provided by the plasma membrane.
C) a complex "motor" embedded in the cell wall and plasma membrane.
D) a basal body that is similar in structure to the cell's centrioles.
E) a membrane-enclosed organelle with motor proteins.

Answer: C

Prokaryotic ribosomes differ from those present in eukaryotic cytosol. Because of this, which of the following is correct?
A) Some antibiotics can block protein synthesis in bacteria without effects in the eukaryotic host.
B) Eukaryotes did not evolve from prokaryotes.
C) Translation can occur at the same time as transcription in eukaryotes but not in prokaryotes.
D) Some antibiotics can block the synthesis of peptidoglycan in the walls of bacteria.
E) Prokaryotes are able to use a much greater variety of molecules as food sources than can eukaryotes.

Answer: A

Prokaryotes' essential genetic information is located in the
A) nucleolus.
B) nucleoid.
C) nucleosome.
D) plasmids.
E) exospore.

Answer: B

Regarding prokaryotic genetics, which statement is correct?
A) Crossing over during prophase I introduces some genetic variation.
B) Prokaryotes feature the union of haploid gametes, as do eukaryotes.
C) Prokaryotes exchange some of their genes by conjugation, the union of haploid gametes, and transduction.
D) Mutation is a primary source of variation in prokaryote populations.
E) Prokaryotes skip sexual life cycles because their life cycle is too short.

Answer: D

Which of these statements about prokaryotes is correct?
A) Bacterial cells conjugate to mutually exchange genetic material.
B) Their genetic material is confined within vesicles known as plasmids.
C) They divide by binary fission, without mitosis or meiosis.
D) The persistence of bacteria throughout evolutionary time is due to their genetic homogeneity (in other words, sameness).
E) Genetic variation in bacteria is not known to occur, because of their asexual mode of reproduction.

Answer: C

Carl Woese and collaborators identified two major branches of prokaryotic evolution. What was the basis for dividing prokaryotes into two domains?
A) microscopic examination of staining characteristics of the cell wall
B) metabolic characteristics such as the production of methane gas
C) metabolic characteristics such as chemoautotrophy and photosynthesis
D) genetic characteristics such as ribosomal RNA sequences
E) ecological characteristics such as the ability to survive in extreme environments

Answer: D

A hypothetical bacterium swims among human intestinal contents until it finds a suitable location on the intestinal lining. It adheres to the intestinal lining using a feature that also protects it from phagocytes, bacteriophages, and dehydration. Fecal matter from a human in whose intestine this bacterium lives can spread the bacterium, even after being mixed with water and boiled. The bacterium is not susceptible to the penicillin family of antibiotics. It contains no plasmids and relatively little peptidoglycan.

54) Adherence to the intestinal lining by this bacterium is due to its possession of
A) fimbriae.
B) pili.
C) a capsule.
D) a flagellum.
E) a cell wall with an outer lipopolysaccharide membrane.

Answer: C

Genetic variation in bacterial populations cannot result from
A) transduction.
B) transformation
C) conjugation
D) mutation.
E) meiosis.

Answer: E

All protists are
A) unicellular.
B) eukaryotic.
C) symbionts.
D) monophyletic.
E) mixotrophic.

Answer: B

An individual mixotroph loses its plastids, yet continues to survive. Which of the following most likely accounts for its continued survival?
A) It relies on photosystems that float freely in its cytosol.
B) It must have gained extra mitochondria when it lost its plastids.
C) It engulfs organic material by phagocytosis or by absorption.
D) It has an endospore.
E) It is protected by a case made of silica.

Answer: C

Which of the following was derived from an ancestral cyanobacterium?
A) chloroplast
B) mitochondrion
C) hydrogenosome
D) mitosome
E) Two of the responses above are correct.

Answer: A

Which of the following statements about dinoflagellates is true?
A) They possess two flagella.
B) All known varieties are autotrophic.
C) Their walls are usually composed of silica plates.
D) Many types lack mitochondria.
E) Their dead cells accumulate on the seafloor, and are mined to serve as a filtering material.

Answer: A

Which process results in genetic recombination, but is separate from the process by which the population size of Paramecium increases?
A) budding
B) meiotic division
C) mitotic division
D) conjugation
E) binary fission

Answer: D

A large seaweed that floats freely on the surface of deep bodies of water would be expected to lack which of the following?
A) thalli
B) bladders
C) holdfasts
D) gel-forming polysaccharides

Answer: C

The chloroplasts of land plants are thought to have been derived according to which evolutionary sequence?
A) cyanobacteria → green algae → land plants
B) cyanobacteria → green algae → fungi → land plants
C) red algae → brown algae → green algae → land plants
D) cyanobacteria → red algae → green algae → land plants

Answer: A

The chloroplasts of all of the following are thought to be derived from ancestral red algae, except those of
A) golden algae.
B) diatoms.
C) dinoflagellates.
D) green algae.
E) brown algae.

Answer: D

Green algae differ from land plants in that many green algae
A) are heterotrophs.
B) are unicellular.
C) have plastids.
D) have alternation of generations.
E) have cell walls containing cellulose.

Answer: B

According to the endosymbiotic theory of the origin of eukaryotic cells, how did mitochondria originate?
A) from infoldings of the plasma membrane, coupled with mutations of genes for proteins in energy-transfer reactions
B) from engulfed, originally free-living proteobacteria
C) by secondary endosymbiosis
D) from the nuclear envelope folding outward and forming mitochondrial membranes
E) when a protoeukaryote engaged in a symbiotic relationship with a protocell

Answer: B

Which protists are in the same eukaryotic supergroup as land plants?
A) green algae
B) dinoflagellates
C) red algae
D) brown algae
E) both green algae and red algae

Answer: E

The structural integrity of bacteria is to peptidoglycan as the structural integrity of plant spores is to
A) lignin.
B) cellulose.
C) secondary compounds.
D) sporopollenin.

Answer: D

All of the following are common to both charophytes and land plants except
A) sporopollenin.
B) lignin.
C) chlorophyll a.
D) cellulose.
E) chlorophyll b.

Answer: B

The functional role of sporopollenin is primarily to
A) comprise spore surface structures that catch the wind and assist in spore dispersal.
B) reduce dehydration.
C) make spores less dense and able to disperse more readily.
D) repel toxic chemicals.
E) provide nutrients to spores.

Answer: B

The following are all adaptations to life on land except
A) rings of cellulose-synthesizing complexes.
B) cuticles.
C) tracheids.
D) reduced gametophyte generation.
E) seeds.

Answer: A

Which of the following is true of the life cycle of mosses?
A) The haploid generation grows on the sporophyte generation.
B) Spores are primarily distributed by water currents.
C) Antheridia and archegonia are produced by gametophytes.
D) The sporophyte generation is dominant.
E) The growing embryo gives rise to the gametophyte.

Answer: C

In which of the following taxa does the mature sporophyte depend completely on the gametophyte for nutrition?
A) Pterophyta
B) Bryophyta
C) horsetail (Equisetum)
D) Pterophyta, Bryophyta, and horsetail (Equisetum)
E) Pterophyta and Bryophyta

Answer: B

Which of the following is not evidence that charophytes are the closest algal relatives of plants?
A) similar sperm structure
B) the presence of chloroplasts
C) similarities in cell wall formation during cell division
D) genetic similarities in chloroplasts
E) similarities in proteins that synthesize cellulose

Answer: B

Which of the following is a land plant that has flagellated sperm and a sporophyte-dominated life cycle?
A) fern
B) moss
C) liverwort
D) charophyte
E) hornwort

Answer: A

The seed coat's most important function is to provide
A) a nonstressful environment for the megasporangium.
B) the means for dispersal.
C) dormancy.
D) a nutrient supply for the embryo.
E) desiccation resistance.

Answer: E

In addition to seeds, which of the following characteristics are unique to the seed-producing plants?
A) sporopollenin
B) lignin present in cell walls
C) pollen
D) use of air currents as a dispersal agent
E) megaphylls

Answer: C

Gymnosperms differ from both extinct and extant (living) ferns because they
A) are woody.
B) have macrophylls.
C) have pollen.
D) have sporophylls.
E) have spores.

Answer: C

Which of the following statements correctly describes a portion of the pine life cycle?
A) Female gametophytes use mitosis to produce eggs.
B) Seeds are produced in pollen-producing cones.
C) Pollen grains contain female gametophytes.
D) A pollen tube slowly digests its way through the triploid endosperm.

Answer: A

Which of the following statements is true of the pine life cycle?
A) Cones are homologous to the capsules of moss plants.
B) The pine tree is a gametophyte.
C) Male and female gametophytes are in close proximity during gamete synthesis.
D) Conifer pollen grains contain male gametophytes.
E) Double fertilization is a relatively common phenomenon.

Answer: D

All of the following cellular structures are functionally important in cells of the gametophytes of both angiosperms and gymnosperms except
A) haploid nuclei.
B) mitochondria.
C) cell walls.
D) chloroplasts.
E) peroxisomes.

Answer: D

Which structure is common to both gymnosperms and angiosperms?
A) stigma
B) carpel
C) ovule
D) ovary
E) anthers

Answer: C

What is true of stamens, sepals, petals, carpels, and pinecone scales?
A) They are female reproductive parts.
B) None are capable of photosynthesis.
C) They are modified leaves.
D) They are found on flowers.
E) They are found on angiosperms.

Answer: C

Which of the following is a characteristic of all angiosperms?
A) complete reliance on wind as the pollinating agent
B) double internal fertilization
C) free-living gametophytes
D) carpels that contain microsporangia
E) ovules that are not contained within ovarie

Answer: B

Carpels and stamens are
A) sporophyte plants in their own right.
B) gametophyte plants in their own right.
C) gametes.
D) spores.
E) modified sporophylls.

Answer: E

Which of the following is a true statement about angiosperm carpels?
A) Carpels are features of the gametophyte generation.
B) Carpels consist of anther and stamen.
C) Carpels are structures that directly produce male gametes.
D) Carpels surround and nourish the female gametophyte.
E) Carpels consist of highly modified microsporangia.

Answer: D

Which of the following flower parts develops into a seed?
A) ovule
B) ovary
C) fruit
D) stamen

Answer: A

Which of the following flower parts develops into the pulp of a fleshy fruit?
A) stigma
B) style
C) ovule
D) ovary
E) micropyle

Answer: D

Angiosperms are the most successful terrestrial plants. Which of the following features is unique to them and helps account for their success?
A) wind pollination
B) dominant gametophytes
C) fruits enclosing seeds
D) embryos enclosed within seed coats
E) sperm cells without flagella

Answer: C

What is the greatest threat to plant diversity?
A) insects
B) grazing and browsing by animals
C) pathogenic fungi
D) competition with other plants
E) human population growth

Answer: E

Gymnosperms and angiosperms have the following in common except
A) seeds.
B) pollen.
C) vascular tissue.
D) ovaries.
E) ovules.

Answer: D

Which of the following is not a characteristic that distinguishes gymnosperms and angiosperms from other plants?
A) alternation of generations
B) ovules
C) integuments
D) pollen
E) dependent gametophytes

Answer: A

Which structure(s) must pass through the micropyle for successful fertilization to occur in angiosperms?
A) only one sperm nucleus
B) two sperm nuclei
C) the pollen tube
D) Two of the responses above are correct.

Answer: D

How have fruits contributed to the success of angiosperms?
A) by nourishing the plants that make them
B) by facilitating dispersal of seeds
C) by attracting insects to the pollen inside
D) by producing sperm and eggs inside a protective coat
E) by producing triploid cells via double fertilization

Answer: B

Which of the following statements is true of monocots?
A) They are currently thought to be polyphyletic.
B) The veins of their leaves form a netlike pattern.
C) They, along with the eudicots, magnoliids, and basal angiosperms, are currently placed in the phylum Anthophyta.
D) Each possesses multiple cotyledons.
E) They are in the clade that includes most of our crops, except the cereal grains.

Answer: C

Which of the following are structures of angiosperm gametophytes?
A) immature ovules
B) pollen tubes
C) ovaries
D) stamens
E) sepals

Answer: B

Which of the following sex and generation combinations most directly produces the megasporangium of pine ovules?
A) male gametophyte
B) female gametophyte
C) male sporophyte
D) female sporophyte

Answer: D

Which of the following conclusions is supported by the research of both Went and Charles and Francis Darwin on shoot responses to light?
A) When shoots are exposed to light, a chemical substance migrates toward the light.
B) Agar contains a chemical substance that mimics a plant hormone.
C) A chemical substance involved in shoot bending is produced in shoot tips.
D) Once shoot tips have been cut, normal growth cannot be induced.
E) Light stimulates the synthesis of a plant hormone that responds to light.

Answer: C

According to the acid growth hypothesis, auxin works by
A) dissolving sieve plates, permitting more rapid transport of nutrients.
B) dissolving the cell membranes temporarily, permitting cells that were on the verge of dividing to divide more rapidly.
C) changing the pH within the cell, which would permit the electron transport chain to operate more efficiently.
D) increasing wall plasticity and allowing the affected cell walls to elongate.
E) greatly increasing the rate of deposition of cell wall material.

Answer: D

The rapid leaf movements resulting from a response to touch (thigmotropism) primarily involve
A) rapid growth response.
B) potassium channels.
C) nervous tissue.
D) aquaporins.
E) stress proteins.

Answer: B

Acoelomates are characterized by
A) the absence of a brain.
B) the absence of mesoderm.
C) deuterostome development.
D) a coelom that is not completely lined with mesoderm.
E) a solid body without a cavity surrounding internal organs.

Answer: E

The distinction between sponges and other animal phyla is based mainly on the absence versus the presence of
A) a body cavity.
B) a complete digestive tract.
C) a circulatory system.
D) true tissues.
E) mesoderm.j

Answer: D

Which characteristic(s) is (are) shared by both cnidarians and flatworms?
A) dorsoventrally flattened bodies
B) true muscle
C) radial symmetry
D) a digestive system with a single opening
E) two of these

Answer: D

A land snail, a clam, and an octopus all share
A) a mantle.
B) a radula.
C) gills.
D) embryonic torsion.
E) distinct cephalization

Answer: A

Which phylum is characterized by animals that have a segmented body?
A) Cnidaria
B) Platyhelminthes
C) Porifera
D) Arthropoda
E) Mollusca

Answer: D

Which of the following combinations of phylum and description is incorrect?
A) Echinodermata–bilateral symmetry as a larva, coelom present
B) Nematoda–roundworms, pseudocoelomate
C) Cnidaria–radial symmetry, polyp and medusa body forms
D) Platyhelminthes–flatworms, gastrovascular cavity, acoelomate
E) Porifera–gastrovascular cavity, coelom present

Answer: E

What do all craniates have that earlier chordates did not have?
A) brain
B) vertebrae
C) cartilaginous pipe surrounding notochord
D) partial or complete skull
E) bone

Answer: D

The swim bladder of ray-finned fishes
A) was probably modified from simple lungs of chondrichthyans.
B) developed into lungs in saltwater fishes.
C) first appeared in sharks.
D) provides for regulation of buoyancy.
E) Two of the options listed are correct.

Answer: D

Which of these species is currently thought to have coexisted (at the same time and places) with H. neanderthalensis?
A) H. erectus
B) H. ergaster
C) H. habilis
D) H. sapiens

Answer: D

Which of the following is the most inclusive (most general) group, all of whose members have fully opposable thumbs?
A) apes
B) Homo
C) anthropoids
D) hominins
E) primates

Answer: C

Due to its system of nine air sacs connected to the lungs, the respiratory system of birds is arguably the most effective respiratory system of all air-breathers. Upon inhalation, air first flows into posterior air sacs, then into the lungs, and then into anterior air sacs on the way to being exhaled. Thus, there is one-way flow of air through the lungs, along thousands of tubules called parabronchi.

94) Which feature of some carinates has the same effect on weight as the presence of air sacs?
A) presence of a large, heavily keratinized beak
B) absence of a urinary bladder
C) presence of a carina (keel)
D) number of chambers in the heart
E) presence of large pectoral muscles

Answer: B