Bio 2 Flashcards

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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 undergo ready fossilization in sedimentary rock.

E) They possess typical prokaryotic flagella.

B)They are subject to lysis in hypotonic conditions


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.



Which is the bacterial structure that acts as a selective barrier, allowing nutrients to enter the cell and wastes to leave the cell ?

A) plasma membrane

B) capsule

C) cell wall
D) nucleoid region

E) pili



Which statement about bacterial cell walls is false?

A) Bacterial cell walls differ in molecular composition from plant cell walls

.B) Cell walls prevent cells from bursting in hypotonic environments.

C) Cell walls prevent cells from dying in hypertonic conditions.

D) Bacterial cell walls are similar in function to the cell walls of many protists, fungi, and


E) Cell walls provide the cell with a degree of physical protection from the environment.



Which of these is the most common compound in the cell walls of gram-positive bacteria?

A) cellulose

B) lipopolysaccharide

C) lignin
D) peptidoglycan

E) protein



Penicillin is an antibiotic that inhibits enzymes from catalyzing the synthesis of peptidoglycan, so which prokaryotes should be most vulnerable to inhibition by penicillin?

A) mycoplasmas
B) gram-positive bacteria

C) archaea
D) gram-negative bacteria

E) endospore-bearing bacteria



The predatory bacterium, Bdellovibrio bacteriophorus, drills into a prey bacterium and, once inside, digests it. In an attack upon a gram-negative bacterium that has a slimy cell covering which can inhibit phagocytosis, what is the correct sequence of structures penetrated by B. bacteriophorus on its way to the preyʹs cytoplasm?

1. membrane composed mostly of lipopolysaccharide 2. membrane composed mostly of phospholipids
3. peptidoglycan
4. capsule

Correct sequence would be:


Capsule - Membrane composed of polysaccharide-peptidoglycan-membrane composed of phospholipids


Jams, jellies, preserves, honey, and other foodstuffs with a 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) undergo death by lysis. D) are obligate anaerobes.

E) are unable to swim through these thick and viscous materials.



In a hypothetical situation, the genes for sex pilus construction and for tetracycline resistance are located together on the same plasmid within a particular bacterium. If this bacterium readily performs conjugation involving a copy of this plasmid, then the result should be

A) a transformed bacterium.
B) the rapid spread of tetracycline resistance to other bacteria in that habitat.

C) the subsequent loss of tetracycline resistance from this bacterium. D) the production of endospores among the bacteriumʹs progeny.

E) the temporary possession by this bacterium of a completely diploid genome.



In a bacterium that possesses antibiotic resistance and the potential to persist through very adverse conditions, such as freezing, drying, or high temperatures, DNA should be located within, or be part of, which structures?

1.nucleoid region






A) 1 only

B)1 and 4

C) 1 and 5

D) 1,3, and 5



Which 2 structures play direct roles in permitting bacteria to adhere to each other, or to other surfaces

1. capsules




5. flagella

A) 1 and 2

B) 1 and 3

C) 2and3

D) 3 and 4

E) 3 and 5



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 ʺmotorʺ embedded in the cell wall and plasma membrane.

D) a basal body that is similar in structure to the cellʹs centrioles.



Prokaryotic ribosomes differ those present in eukaryotic cytosol. Because of this, which of the following is correct?

A) Some selective antibiotics can block protein synthesis of bacteria without effects on protein synthesis 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


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.



Which statement about the genomes of prokaryotes is correct?

A) Prokaryotic genomes are diploid throughout most of the cell cycle.

B) Prokaryotic chromosomes are sometimes called plasmids.

C) Prokaryotic cells have multiple chromosomes, ʺpackedʺ with a relatively large

amount of protein.

D) The prokaryotic chromosome is not contained within a nucleus but, rather, is found at

the nucleoid region.

E) Prokaryotic genomes are composed of linear DNA (that is, DNA existing in the form

of a line with two ends).



If a bacterium regenerates from an endospore that did not possess any of the plasmids that were contained in its original parent cell, the regenerated bacterium will probably

A) lack antibiotic-resistant genes. B) lack a cell wall.

C) lack a chromosome.
D) lose base pairs from its chromosome.

E) be unable to survive in its normal environment.



Relative to G positive

Which of the following is composed almost entirely of peptidoglycan?

A) endospore

B) sex pilus

C) flagellum

D) cell wall

E) capsule



Which of the following requires ATP to function, and permits some species to respond to taxes (plural of taxis)?

A) endospore

B) sex pilus

C) flagellum

D) cell wall

E) capsule



Not present in all bacteria, this cell covering enables cells that possess it to resist the defenses of host organisms:

A) endospore

B) sex pilus

C) flagellum

D) cell wall

E) capsule



Not present in all bacteria, this structure enables those that possess it to germinate after exposure to harsh conditions, such as boiling:

A) endospore

B) sex pilus

C) flagellum

D) cell wall




Which of the following is a structure that permits conjugation to occur?

A) endospore

B) sex pilus

C) flagellum

D) cell wall

E) capsule



If this structure connects the cytoplasm of two bacteria, one of these cells may gain new genetic material:

A) Endospore

B) Sex pilus

C) flagellum

D) capsule



Which of the following contains a copy of the chromosome, along with a small amount of dehydrated cytoplasm, w within a tough wall

A) endospore

B) sex pilus

C) flagellum

D) cell wall

E) capsule



Regarding prokaryotic reproduction, which statement is correct?A) Prokaryotes form gametes by meiosis.

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.



Which of these statements about prokaryotes is correct?

A) Bacterial cells conjugate to mutually exchange genetic material.

B) Their genetic material is confined within a nuclear envelope.

C) They divide by binary fission, without mitosis or meiosis.

D) The persistence of bacteria throughout evolutionary time is due to their genetic

homogeneity (i.e., sameness).

E) Genetic variation in bacteria is not known to occur, nor should it occur, because of

their asexual mode of reproduction.



In this 8-year experiment, 12 populations of E. coli, each begun from a single cell, were grown in low-glucose conditions for 20,000 generations. Each culture was introduced to fresh growth medium every 24 hours. Occasionally, samples were removed from the populations, and their fitness in low-glucose conditions was tested against that of members sampled from the ancestral (common ancestor) E. coli population

Which term best describes what has occurred among the experimental populations of cells over this 8-year period?

A) microevolution

B) speciation

C) adaptive radiation

D) sexual selection

E) stabilizing selection



If it occurs in the absence of any other type of adaptation listed here, which of these is least reasonable in terms of promoting bacterial survival over evolutionary time in a low-glucose environment



What can be inferred from figure 27.1 ?

A) Most of the genetic change that permitted adaptation to the new, low-glucose

environment occurred toward the conclusion of the experiment.

B) Rates of mitosis increased over the course of the experiment.

C) The highest rate of genetic change occurred during the first quarter of the experiment.

D) After 5,000 generations, the bacteria were 100% more fit than the original, ancestral




If the vertical axis to figure 27.1 refers to, "Darwinian fitness", then which of these is the most valid and accurate measure of fitness ?

A) number of daughter cells produced per mother cell per generation

B) amount of ATP generated per cell per unit time

C) average swimming speed of cells through the growth medium

D) amount of glucose synthesized per unit time

E) number of generations per unit time



If new genetic variations in the experimental populations arose solely by spontaneous mutations, then the most effective process for subsequently increasing the prevalence of the beneficial mutations in the population over the course of generations is


B) binary fission.

C) conjugation.
D) transformation.

E) meiosis.



E. coli cells typically make most of their ATP by metabolizing glucose. Under the conditions of this experiment, what should be true of E. coliʹs generation time (especially early in the course of the experiment, but less so later on)?

A) Generation time should be the same as in the typical environment.

B) Generation time should be faster than in the typical environment.

C) Generation time should be slower than in the typical environment.

D) It is theoretically impossible to make any predictions about generation time, under these conditions.



32) If the experimental population of E. coli lacks an F factor or F plasmid, and if bacteriophage are excluded from the bacterial cultures, then which of these is a means by which beneficial mutations might be transmitted horizontally to other E. coli cells?

A) via sex pili
B) via transduction

C) via conjugation
D) via transformation

E) both A and C above



Which term is least closely associated with the others?

A) Hfr cells making use of a sex pilus

B) rolling circle replication
C) the ʺtoilet paperʺ model of replication

D) conjugation involving an F factor

E) recombination involving a bacteriophage



What is occurring at Time C that is decreasing the DNA content?

A) crossing-over

B) cytokinesis
C) meiosis
D) degradation of DNA that was not retained in the recipientʹs chromosome

E) reversal of the direction of conjugation



How is the recipient cell different at Time D than it was at Time A?

A) It has a greater number of genes.

B) It has a greater mass of DNA.
C) It has a different sequence of base pairs. D) It contains bacteriophage DNA.

E) It has a greater number of introns.



Which two processes are responsible for the shape of the curve at Time B?

1. transduction
2. entry of single-stranded Hfr DNA
3. rolling circle replication of single-stranded Hfr DNA

4. activation of DNA pumps in plasma membrane
5. ʺtoilet paperʺ replication of recipient cellʹs plasmids

A) 1 and 4

B) 2 and 3

C) 3and5

D) 1 and 3

E) 4 and 5



During which two times can the recipient accurately be described as ʺrecombinantʺ due to the sequence of events portrayed in Figure 27.2?

A) during Times C and D

B) during Times A and C

C) during Times B and C

D) during Times A and B

E) during Times B and D



Which question, arising from the results depicted in Figure 27.2, is most interesting from a genetic perspective, and has the greatest potential to increase our knowledge base?

A) If reciprocal crossing-over could occur even if the piece of donated Hfr DNA is identical to the homologous portion of the recipientʹs chromosome, what prevents this from occurring?

B) Why do geneticists refer to the same structure by at least three different names: sex pilus, mating bridge, and conjugation tube? Why all the jargon?

C) What forces are generally responsible for disrupting the mating bridge?

D) How is it that a recipient cell does not necessarily become an Hfr cell as the result of

conjugation with an Hfr cell?

E) What makes a cell an ʺHfr cellʺ?



1. autotroph 2. heterotroph 3. phototroph 4. chemotroph

40) an organism that obtains its energy from chemicals

A) 1 only

B) 2 only

C) 3 only

D) 4 only

E) 1 and 4



1. autotroph 2. heterotroph 3. phototroph 4. chemotroph

A prokaryote that obtains both energy and carbon as it decomposes seas organisms



1. autotroph 2. heterotroph 3. phototroph 4. chemotroph

an organism that obtains both carbon and energy by ingesting prey

A) 1 only

B) 4 only

C) 1and3

D) 2 and 4

E) 1, 3, and 4



1. autotroph 2. heterotroph 3. phototroph 4. chemotroph

an organism that relies on photons to excite electrons within its membranes

A) 1 only

B) 3 only

C) 1and3

D) 2 and 4

E) 1, 3, and 4



Which of the following are responsible for many human diseases?

A) photoautotrophs

B) photoheterotrophs
C) chemoautotrophs
D) chemoheterotrophs that perform decomposition

E) parasitic chemoheterotrophs



Cyanobacteria are
A) photoautotrophs.

B) photoheterotrophs.
C) chemoautotrophs.
D) chemoheterotrophs that perform decomposition.

E) parasitic chemoheterotrophs.



Which of the following use light energy to synthesize organic compounds from CO2?

A) photoautotrophs

B) photoheterotrophs

C) chemoautotrophs
D) chemoheterotrophs that perform decomposition

E) parasitic chemoheterotrophs



Which of the following obtain energy by oxidizing inorganic substances; energy that is used, in part, to fix co2

A) photoautotrophs

B) photoheterotrophs

C) chemoautotrophs
D) chemoheterotrophs that perform decomposition

E) parasitic chemoheterotrophs



Which of the following use light energy to generate ATP, but do not release oxygen?

A) photoautotrophs

B) photoheterotrophs

C) chemoautotrophs

D) chemoheterotrophs that perform decomposition

E) parasitic chemoheterotrophs



Which of the following use light energy to generate ATP, but do not release oxygen?

A) photoautotrophs

B) photoheterotrophs
C) chemoautotrophs
D) chemoheterotrophs that perform decomposition

E) parasitic chemoheterotrophs



Which of the following are responsible for high levels of O2 in Earthʹs atmosphere?

A) photoautotrophs

B) photoheterotrophs

C) chemoautotrophs
D) chemoheterotrophs that perform decomposition

E) parasitic chemoheterotrophs



Modes of obtaining nutrients, used by at least some bacteria, include all of the following


A) chemoautotrophy.

B) photoautotrophy.

C) heteroautotrophy.

D) chemoheterotrophy.

E) photoheterotrophy.



Only certain prokaryotes can perform nitrogen fixation, but nitrogen-fixing prokaryotes are not known to live inside animals. Thus, how do animals gain access to fixed nitrogen?

A) They may breathe it in from air that has experienced lightning discharges.

B) They may ingest nitrogen fixers.

C) They may ingest plants that harbor nitrogen fixers, or plants that absorbed fixed nitrogen from the soil.

D) They may ingest other animals that had done either (B) or (C) above.

  1. E) Answers (B), (C), and (D) above are all possible.



Given that the enzymes that catalyze nitrogen fixation are inhibited by oxygen, what are two ʺstrategiesʺ that nitrogen-fixing prokaryotes might use to protect these enzymes from oxygen?

1couple them with photosystem II (the 2photosystem that splits water molecules) 3package them in membranes that are 4impermeable to all gases
5be obligate anaerobes
6be strict aerobes

package these enzymes in specialized cells or compartments that inhibit oxygen entry

A) 1 and 4

B) 2 and 4

C) 2and5

D) 3 and 4

E) 3 and 5



The data were collected from the heterocytes of a nitrogen-fixing cyanobacterium inhabiting equatorial ponds. Study the graph below and choose the most likely explanation for the shape of the curve.

A) Enough O2 enters heterocytes during hours of peak photosynthesis to have a somewhat-inhibitory affect on nitrogen fixation.

B) Light-dependent reaction rates must be highest between 1800 hours and 0600 hours.

C) Atmospheric N2 levels increase at night because plants are no longer metabolizing

this gas, so are not absorbing this gas through their stomata.

D) Heterocyte walls become less permeable to N2 influx during darkness.

E) The amount of fixed nitrogen that is dissolved in the pond water in which the cyanobacteria are growing peaks at the close of the photosynthetic day (1800 h).



Mitochondria are thought to be the descendants of certain alpha -proteobacteria. They are, however, no longer able to lead independent lives because most genes originally present on their chromosome have moved to the nuclear genome. Which phenomenon accounts for the movement of these genes?

A) horizontal gene transfer

B) binary fission

C) alternative gene splicing

D) meiosis

E) plasmolysis



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



Which statement about the domain Archaea is false?

A) Genetic prospecting has recently revealed the existence of many previously unknown

archean species.

B) Some archaeans can reduce CO2 to methane.

C) The genomes of archaeans are unique, containing no genes that originated within bacteria.

D) Some archaeans can inhabit solutions that are nearly 30% salt.

E) Some archaeans are adapted to waters with temperatures above the boiling point.



If archaeans are more closely related to eukaryotes than to bacteria, then which of the following is a reasonable prediction?

A) Archaean DNA should have no introns.
B) Archaean chromosomes should have no protein bonded to them.

C) Archaean DNA should be single-stranded.
D) Archaean ribosomes should be larger than typical prokaryotic ribosomes.

E) Archaeans should lack cell walls.



Which of the following traits do archaeans and bacteria share?

1composition of the cell wall

2presence of plasma membrane

3lack of a nuclear envelope

4identical rRNA sequences

A) 1 only

B) 3 only

C) 1and3

D) 2 and 3

E) 2 and 4



Assuming that each of these possesses a cell wall, which prokaryotes should be expected to be most strongly resistant to plasmolysis in hypertonic environments?

A) extreme halophiles

B) extreme thermophiles

C) methanogens

D) cyanobacteria

E) nitrogen-fixing bacteria that live in root nodules



The thermoacidophile, Sulfolobus acidocaldarius lacks peptidoglycan. What is likely to be true of this species?
1. It is a bacterium.
2. It is an archaean.

3. The optimal pH of its enzymes will lie above pH 7.

4. The optimal pH of its enzymes will lie below pH 7.

5. It could inhabit certain hydrothermal springs.
6. It could inhabit alkaline hot springs.

A) 1, 3, and 6

B) 2, 4, and 6

C) 2,4,and5

D) 1, 3, and 5

E) 1, 4, and 5



A fish that had been salt-cured subsequently develops a reddish color. You suspect that the fish has been contaminated by the extreme halophile, Halobacterium. Which of these features of cells removed from the surface of the fish, if confirmed, would support your suspicion?

1. the presence of the same photosynthetic pigments found in cyanobacteria 2. cell walls that lack peptidoglycan
3. cells that are isotonic to conditions on the surface of the fish
4. its cells contain bacteriorhodopsin

5. the presence of very large numbers of ion pumps in its plasma membrane

A) 2 and 5

B) 3 and 4

C) 1,4,and5

D) 3, 4, and 5

E) 2, 3, 4, and 5



The termite gut protist, Mixotricha paradoxa, has at least two kinds of bacteria attached to its outer surface. One kind is a spirochete that propels its host through the termite gut. A second type of bacteria synthesizes ATP, some of which is used by the spirochetes. The locomotion provided by the spirochetes introduces the ATP-producing bacteria to new food sources. Which term(s) is (are) applicable to the relationship between the two kinds of bacteria?

4metabolic cooperation

A) 1 only

B) 1 and 2

C) 2and3

D) 1, 3, and 4
E) all four terms



What is the primary ecological role of prokaryotes?

A) parasitizing eukaryotes, thus causing diseases

B) breaking down organic matter
C) metabolizing materials in extreme environments

D) adding methane to the atmosphere

E) serving as primary producers in terrestrial environments



If all prokaryotes on Earth suddenly vanished, which of the following would be the most likely and most direct result?

A) The number of organisms on Earth would decrease by 10—20%.

B) Human populations would thrive in the absence of disease.

C) Bacteriophage numbers would dramatically increase.
D) The recycling of nutrients would be greatly reduced, at least initially.

E) There would be no more pathogens on Earth.



How can prokaryotes be considered to be more successful on Earth than humans?

A) Prokaryotes are much more numerous and have more biomass.

B) Prokaryotes occupy more diverse habitats. C) Prokaryotes are more diverse in metabolism.

D) Only B and C are correct.

E) A, B, and C are correct.



Many physicians administer antibiotics to patients at the first sign of any disease symptoms. Why can this practice cause more problems for these patients, and for others not yet infected?

A) The antibiotic administered may kill viruses that had been keeping the bacteria in check.

B) Antibiotics may cause other side effects in patients.

C) Overuse of antibiotics can select for antibiotic-resistant strains of bacteria.

D) Particular patients may be allergic to the antibiotic.

E) Antibiotics may interfere with the ability to identify the bacteria present.



Broad-spectrum antibiotics inhibit the growth of most intestinal bacteria. Consequently, assuming that nothing is done to counter the reduction of intestinal bacteria, a hospital patient who is receiving broad-spectrum antibiotics is most likely to become

A) unable to fix carbon dioxide.

B) antibiotic resistant.

C) unable to fix nitrogen.
D) unable to synthesize peptidoglycan.

E) deficient in certain vitamins.



Which statement about gram-negative bacteria is correct?

A) Penicillins are the best antibiotics to use against them.

B) They often possess an outer membrane containing toxic lipopolysaccharides.

C) Their chromosomes are composed of DNA tightly wrapped around large amounts of

histone proteins.

D) Their cell walls are primarily composed of peptidoglycan.



Protists are alike in that all are

A) unicellular.

B) eukaryotic.
C) symbionts.
D) monophyletic.

E) autotrophic.



Biologists have long been aware that the defunct kingdom Protista is paraphyletic. Which of these statements is both true and consistent with this conclusion?

A) Many species within this kingdom were once classified as monerans.

B) Animals, plants, and fungi arose from different protist ancestors.

C) The eukaryotic condition has evolved only once among the protists, and all eukaryotes are descendants of that first eukaryotic cell.

D) Chloroplasts among various protists are similar to those found in prokaryotes.

E) Some protists, all animals, and all fungi share a protist common ancestor, but these

protists, animals, and fungi are currently assigned to three different kingdoms.



The strongest evidence for the endosymbiotic origin of eukaryotic organelles is the similarity between extant prokaryotes and which of the following?

A) nuclei and chloroplasts
B) mitochondria and chloroplasts

C) cilia and mitochondria

D) mitochondria and nuclei

E) mitochondria and cilia



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 prokaryotes
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 protobiont

Answer: B



Which of these statements is false and therefore does not support the hypothesis that certain eukaryotic organelles originated as bacterial endosymbionts? Such organelles

A) are roughly the same size as bacteria.

B) can be cultured on agar, because they make all their own proteins.

C) contain circular DNA molecules.

D) have ribosomes that are similar to those of bacteria.

E) have internal membranes that contain proteins homologous to those of bacterial plasma membranes.



Which process allowed the nucleomorphs of chlorarachniophytes to be first reduced, and then (in a few species) lost altogether, without the loss of any genetic information?

A) conjugation
B) horizontal gene transfer

C) binary fission

D) phagocytosis

E) meiosis



Which organisms represent the common ancestor of all photosynthetic plastids found in eukaryotes?

A) autotrophic euglenids

B) diatoms

C) dinoflagellates

D) red algae

E) cyanobacteria



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 siliceous case.



Which of these was not derived from an ancestral alpha proteobacterium?

A) chloroplast

B) mitochondrion

C) hydrogenosome

D) mitosome

E) kinetoplast



Which of these taxa contains species that produce potent toxins that can cause extensive fish kills, contaminate shellfish, and poison humans?

A) red algae


C) diplomonads

D) euglenids

E) golden algae



Which of the following pairs of protists and their characteristics is mismatched?

A) apicomplexans : internal parasites

B) golden algae : planktonic producers

C) euglenozoans : unicellular flagellates

D) ciliates : red tide organisms

E) entamoebas : ingestive heterotrophs



Which of these statements about dinoflagellates is false?

A) They possess two flagella.

B) Some cause red tides.

C) Their walls are composed of cellulose plates.

D) Many types contain chlorophyll.

E) Their dead cells accumulate on the seafloor, and are mined to serve as a filtering material.



Which group includes members that are important primary producers in ocean food webs, causes red tides that kill many fish, and may even be carnivorous?

A) ciliates
B) apicomplexans

C) dinoflagellates

D) brown algae

E) golden algae



You are given an unknown organism to identify. It is unicellular and heterotrophic. It is motile, using many short extensions of the cytoplasm, each featuring the 9+2 filament pattern. It has well-developed organelles and three nuclei, one large and two small. This organism is most likely to be a member of which group?

A) foraminiferans

B) radiolarians

C) ciliates
D) kinetoplastids

E) slime molds



Which of the following is not characteristic of ciliates?
A) They use cilia as locomotory structures or as feeding structures.

B) They are relatively complex cells.
C) They can exchange genetic material with other ciliates by the process of mitosis.

D) Most live as solitary cells in fresh water.

E) They have two or more nuclei.



Which process results in genetic recombination, but is separate from the process wherein the population size of Paramecium increases?

A) budding
B) meiotic division

C) mitotic division

D) conjugation

E) binary fission



Why is the filamentous morphology of the water molds considered a case of convergent evolution with the hyphae (threads) of fungi?

A) Fungi are closely related to the water molds.

B) Body shape reflects ancestor-descendant relationships among organisms.

C) In both cases, filamentous shape is an adaptation for the absorptive nutritional mode of a decomposer.

D) Filamentous body shape is evolutionarily ancestral for all eukaryotes.

E) Both A and B are correct.



The Irish potato famine was caused by an organism that belongs to which group?

A) ciliates

B) oomycetes
C) diatoms
D) apicomplexans

E) dinoflagellates



If one were to apply the most recent technique used to fight potato late blight to the fight against the malarial infection of humans, then one would

A) increase the dosage of the least-expensive antimalarial drug administered to humans.

B) increase the dosage of the most common pesticide used to kill Anopheles mosquitoes.

C) introduce a predator of the malarial parasite into infected humans.

D) use a ʺcocktailʺ of at least three different pesticides against Anopheles mosquitoes.

E) insert genes from a Plasmodium-resistant strain of mosquito into Anopheles mosquitoes.



Diatoms are mostly asexual members of the phytoplankton. Diatoms lack any organelles that might have the 9+2 pattern. They obtain their nutrition from functional chloroplasts, and each diatom is encased within two porous, glasslike valves. Which question would be

most important for one interested in the day-to-day survival of individual diatoms?

A) How does carbon dioxide get into these protists with their glasslike valves?

B) How do diatoms get transported from one location on the waterʹs surface layers to

another location on the surface?

C) How do diatoms with their glasslike valves keep from sinking into poorly lit waters?

D) How do diatoms with their glasslike valves avoid being shattered by the action of


E) How do diatom sperm cells locate diatom egg cells?



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) blades

D) holdfasts

E) gel-forming polysaccharides



The following are all characteristic of the water molds (oomycetes) except A) the presence of filamentous feeding structures.

B) flagellated zoospores.
C) a nutritional mode that can result in the decomposition of dead organic matter. D) a morphological similarity to fungi that is the result of evolutionary convergence.

E) a feeding plasmodium.



Using dead diatoms to ʺpumpʺ CO2 to the seafloor is feasible only if dead diatoms sinkquickly. Consequently, application of mineral fertilizers, such as iron, should be most effective at times when diatom

A) valves are thickest, and laminarin is being produced rather than oil.

B) valves are thickest, and oil is being produced rather than laminarin.

C) valves are thinnest, and laminarin is being produced rather than oil.

D) valves are thinnest, and oil is being produced rather than laminarin.



Thread-like pseudopods that can perform phagocytosis are generally characteristic of which group?

A) radiolarians and forams

B) gymnamoebas

C) entamoebas
D) amoeboid stage of cellular slime molds

E) oomycetes



Which of the following produce the dense glassy ooze found in certain areas of the deep-ocean floor?

A) forams
B) dinoflagellates

C) radiolarians

D) ciliates

E) apicomplexans



A snail-like, coiled, porous test (shell) of calcium carbonate is characteristic of which group?

A) diatoms
B) foraminiferans

C) radiolarians

D) gymnamoebas

E) ciliates



Typically as cells grow, their increase in volume outpaces their increase in surface area, and continued survival requires undergoing asexual reproduction to reestablish a healthy surface area to volume ratio. Thus, which of these is least likely to contribute to the ability of a single-celled foraminiferan to grow to a diameter of several centimeters?

A) Its threadlike pseudopods dramatically increase its surface area to volume ratio. B) Its symbiotic algae provide oxygen to the cytoplasm.

C) Its symbiotic algae absorb metabolic waste products from the cytoplasm. D) Its symbiotic algae provide glucose to the cytoplasm.

E) Its calcium carbonate test contributes extra mass.



What makes certain red algae appear red?

A) They live in warm coastal waters.

B) They possess pigments that reflect and transmit red light.

C) They use red light for photosynthesis.
D) They lack chlorophyll.

E) They contain the pigment bacteriorhodopsin.



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 plant

s D) red algae → cyanobacteria → land plants

E) cyanobacteria → red algae → green algae → land plants



The chloroplasts of all of the following are derived from ancestral red algae, except those of

A) golden algae.

B) diatoms.
C) dinoflagellates.

D) green algae.

E) brown algae.



A biologist discovers an alga that is marine, multicellular, and lives at a depth reached only by blue light. This alga probably belongs to which group?

A) red algae
B) brown algae

C) green algae
D) dinoflagellates

E) golden algae



Green algae often differ from land plants in that some green algae

A) are heterotrophs.

B) are unicellular.
C) have plastids.
D) have alternation of generations.

E) have cell walls containing cellulose.



Which taxon of eukaryotic organisms is thought to be directly ancestral to the plant kingdom?

A) golden algae

B) radiolarians

C) foraminiferans

D) apicomplexans

E) green algae



The best evidence for not classifying the slime molds as fungi comes from slime moldsʹ

A) DNA sequences.

B) nutritional modes.

C) choice of habitats.

D) physical appearance.

E) reproductive methods.



Which pair of alternatives is highlighted by the life cycle of the cellular slime molds, such as Dictyostelium?

A) prokaryotic or eukaryotic

B) plant or animal

C) unicellular or multicellular

D) diploid or haploid

E) autotroph or heterotroph



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.



Which kind of plant tissue should lack phragmoplasts?

A) bryophyte tissues

B) diploid tissues of charophytes
C) spore-producing tissues of all land plants
D) tissues performing nuclear division without intervening cytokineses

E) the meristematic tissues of fern gametophytes



The following are common to both charophytes and land plants except

A) sporopollenin.

B) lignin.
C) chlorophyll a.

D) cellulose.

E) chlorophyll b.



The following are common to both charophytes and land plants except

A) sporopollenin.

B) lignin.
C) chlorophyll a.

D) cellulose.

E) chlorophyll b.



A number of characteristics are very similar between charophytes and members of the kingdom Plantae. Of the following, which characteristic does not provide evidence for a close evolutionary relationship between these two groups?

A) alternation of generations

B) chloroplast structure

C) cell plate formation during cytokinesis

D) sperm cell structure

E) ribosomal RNA nucleotide sequences



A researcher wants to develop a test that will distinguish charophytes and land plants from green algae. Which of the following chemicals would be the best subject for such an assay?

A) chlorophylla photosynthetic pigment

B) carotenoidsa class of accessory photosynthetic pigments

C) starcha food storage material

D) glycolate oxidasean peroxisomal enzyme that is associated with photorespiration

E) flavonoidsa class of phenolic compounds that is often associated with chemical signaling



In animal cells and in the meristem cells of land plants, the nuclear envelope disintegrates during mitosis. This disintegration does not occur in the cells of most protists and fungi. According to our current knowledge of plant evolution, which group of organisms should feature mitosis most similar to that of land plants?

A) unicellular green algae

B) cyanobacteria

C) charophytes

D) red algae

E) multicellular green algae



On a field trip, a student in a marine biology class collects an organism that has differentiated organs, cell walls of cellulose, and chloroplasts with chlorophyll a. Based on this description, the organism could be a brown alga, a red alga, a green alga, a charophyte recently washed into the ocean from a freshwater or brackish water source, or a land plant washed into the ocean. The presence of which of the following features would definitively identify this organism as a land plant?

A) alternation of generations

B) sporopollenin

C) rosette cellulose-synthesizing complexes

D) flagellated sperm

E) embryos



Some green algae exhibit alternation of generations. All land plants exhibit alternation of generations. No charophytes exhibit alternation of generations. Keeping in mind the recent evidence from molecular systematics, the correct interpretation of these observations is that

A) charophytes are not related to either green algae or land plants.

B) plants evolved alternation of generations independently of green algae.

C) alternation of generations cannot be beneficial to charophytes.

D) land plants evolved directly from the green algae that perform alternation of


E) scientists have no evidence to indicate whether or not land plants evolved from any

kind of alga.



Which of the following characteristics, if observed in an unidentified green organism, would make it unlikely to be a charophyte?

A) phragmoplast

B) peroxisome

C) apical meristem
D) chlorophylls a and b

E) rosette cellulose-synthesizing complex



Whereas the zygotes of charophytes may remain within maternal tissues during their initial development, one should not expect to observe

A) any nutrients from maternal tissues being used by the zygotes.

B) specialized placental transfer cells surrounding the zygotes.

C) the zygotes undergoing nuclear division.
D) mitochondria in the maternal tissues, or in the tissues of the zygotes.

E) the zygotes digested by enzymes from maternal lysosomes.



Which taxon is essentially equivalent to the ʺembryophytesʺ?

A) Viridiplantae

B) Plantae
C) Pterophyta

D) Bryophyta

E) Charophycea



protection from predators

A) tracheids and phloem

B) secondary compounds
C) cuticle
D) alternation of generations



protection from desiccation

A) tracheids and phloem

B) secondary compounds
C) cuticle
D) alternation of generations



transport of water, minerals, and nutrients

A) tracheids and phloem

B) secondary compounds
C) cuticle
D) alternation of generations



16) Which of the following was not a challenge for survival of the first land plants?

A) sources of water

B) sperm transfer

C) desiccation
D) animal predation

E) absorbing enough light



The following are all adaptations to life on land except

A) rosette cellulose-synthesizing complexes.

B) cuticles.
C) tracheids.
D) reduced gametophyte generation.

E) seeds.



Mitotic activity by the apical meristem of a root makes which of the following more possible?

A) increase of the above-ground stem.
B) decreased absorption of mineral nutrients.

C) increased absorption of CO2.

D) increased number of chloroplasts in roots. E) effective lateral growth of the stem.



Which of the following is a secondary compound of embryophytes?

A) adenosine triphosphate

B) alkaloids
D) chlorophyll a

E) chlorophyll b



Which event during the evolution of land plants probably made the synthesis of secondary compounds most beneficial?

A) the greenhouse effect present throughout the Devonian period

B) the reverse-greenhouse effect during the Carboniferous period

C) the association of the roots of land plants with fungi

D) the rise of herbivory

E) the rise of wind pollination



Which of the following taxa includes the largest amount of genetic diversity among plantlike organisms?

A) Embryophyta

B) Viridiplantae

C) Plantae
D) Charophyceae

E) Tracheophyta



The following characteristics all helped seedless plants become better adapted to land


A) a dominant gametophyte.

B) vascular tissue.

C) a waxy cuticle.
D) stomata on leaves.

E) a branched sporophyte.



A botanist discovers a new species of plant in a tropical rain forest. After observing its anatomy and life cycle, the following characteristics are noted: flagellated sperm, xylem with tracheids, separate gametophyte and sporophyte generations with the sporophyte dominant, and no seeds. This plant is probably most closely related to

A) mosses.
B) charophytes.

C) ferns.
D) gymnosperms.

E) flowering plants.