EXAM 2 Flashcards

The various taxonomic levels (namely, genera, classes, etc.) of the hierarchical classification system differ from each other on the basis of
A) how widely the organisms assigned to each are distributed throughout the environment.
B) their inclusiveness.
C) the relative genome sizes of the organisms assigned to each.
D) morphological characters that are applicable to all organisms.

Linnaeus was a "fixist" who believed that species remained fixed in the form in which they had been created. Linnaeus would have been uncomfortable with
A) classifying organisms using the morphospecies concept.
B) the scientific discipline known as taxonomy.
C) phylogenies.
D) nested, ever-more inclusive categories of organisms.
E) a hierarchical classification scheme.

Which of the following is (are) problematic when the goal is to construct phylogenies that accurately reflect evolutionary history?
A) polyphyletic taxa
B) paraphyletic taxa
C) monophyletic taxa
D) Two of the responses are correct.

Which individual would make the worst systematist? One who is uncomfortable with the
A) Linnaean system of classification.
B) notion of hypothetical phylogenies.
C) PhyloCode method of classification.
D) notion of permanent polytomies

The best classification system is that which most closely
A) unites organisms that possess similar morphologies.
B) conforms to traditional, Linnaean taxonomic practices.
C) reflects evolutionary history.
D) reflects the basic separation of prokaryotes from eukaryotes.

Which of the following pairs are the best examples of homologous structures?
A) bones in the bat wing and bones in the human forelimb
B) owl wing and hornet wing
C) bat wing and bird wing
D) eyelessness in the Australian mole and eyelessness in the North American mole

Some molecular data place the giant panda in the bear family (Ursidae) but place the lesser panda in the raccoon family (Procyonidae). Consequently, the morphological similarities of these two species are probably due to
A) inheritance of acquired characteristics.
B) sexual selection.
C) inheritance of shared derived characters.
D) possession of analogous structures.
E) possession of shared primitive characters.

The importance of computers and of computer software to modern cladistics is most closely linked to advances in
A) light microscopy.
B) radiometric dating.
C) fossil discovery techniques.
D) Linnaean classification.
E) molecular genetics.

Which mutation should least require realignment of homologous regions of a gene that is common to several related species?
A) three-base insertion
B) one-base substitution
C) four-base insertion
D) one-base deletion
E) three-base deletion

Which of the following is true of all horizontally oriented phylogenetic trees, where time advances to the right?
A) Each branch point represents a point in absolute time.
B) Organisms represented at the base of such trees are descendants of those represented at higher levels.
C) The fewer branch points that occur between two taxa, the more divergent their DNA sequences should be.
D) The common ancestor represented by the rightmost branch point existed more recently in time than the common ancestors represented at branch points located to the left.
E) The more branch points there are, the fewer taxa are likely to be represented.

When using a cladistic approach to systematics, which of the following is considered most important for classification?
A) shared primitive characters
B) analogous primitive characters
C) shared derived characters
D) the number of homoplasies
E) overall phenotypic similarity

Cladograms (a type of phylogenetic tree) constructed from evidence from molecular systematics are based on similarities in
A) morphology.
B) the pattern of embryological development.
C) biochemical pathways.
D) habitat and lifestyle choices.
E) mutations to homologous genes.

There is some evidence that reptiles called cynodonts may have had whisker-like hairs around their mouths. If true, then what can be properly said of hair?
A) It is a shared derived character of mammals, even if cynodonts continue to be classified as reptiles.
B) It is a shared derived character of the amniote clade, and not of the mammal clade.
C) It is a shared ancestral character of the amniote clade, but only if cynodonts are reclassified as mammals.
D) It is a shared derived character of the mammals, but only if cynodonts are reclassified as mammals.

A researcher wants to determine the genetic relatedness of several breeds of dog (Canis lupus familiaris). The researcher should compare homologous sequences of this type of biochemical________which can be described as ________.

A) fatty acids; highly conserved
B) lipids; poorly conserved
C) proteins; highly conserved
D) amino acids; highly conserved
E) nucleic acids, poorly conserved

Species that are not closely related and that do not share many anatomical similarities can still be placed together on the same phylogenetic tree by comparing their
A) plasmids.
B) mitochondrial genomes.
C) homologous genes that are poorly conserved.
D) homologous genes that are highly conserved.

The lakes of northern Minnesota are home to many similar species of damselflies of the genus Enallagma that have apparently undergone speciation from ancestral stock since the last glacial retreat about 10,000 years ago. Sequencing which of the following would probably be most useful in sorting out evolutionary relationships among these closely related species?
A) nuclear DNA
B) mitochondrial DNA
C) small nuclear RNA
D) ribosomal RNA
E) amino acids in proteins

What important criterion was used in the late 1960s to distinguish between the three multicellular eukaryotic kingdoms of the five-kingdom classification system?
A) the number of cells present in individual organisms
B) the geological stratum in which fossils first appear
C) the nutritional modes they employ
D) the biogeographic province where each first appears
E) the features of their embryos

Which eukaryotic kingdom is polyphyletic, and therefore unacceptable, based on cladistics?
A) Plantae
B) Fungi
C) Animalia
D) Protista
E) Monera

A large proportion of archaeans are extremophiles, so called because they inhabit extreme environments with high acidity, salinity, and/or temperature. Such environments are thought to have been much more common on the primitive Earth. Thus, modern extremophiles survive only in places that their ancestors became adapted to long ago. Which of the following is, consequently, a valid statement about modern extremophiles, assuming that their habitats have remained relatively unchanged?
A) Among themselves, they should share relatively few ancestral traits, especially those that enabled ancestral forms to adapt to extreme conditions.
B) On a phylogenetic tree whose branch lengths are proportional to the amount of genetic change, the branches of the extremophiles should be shorter than the non-extremophilic archaeans.
C) They should contain genes that originated in eukaryotes that are the hosts for numerous species of bacteria.
D) They should currently be undergoing a high level of horizontal gene transfer with non-extremophilic archaeans.

Which extinct species should be the best candidate to serve as the outgroup for the clade whose common ancestor occurs at position 2 in Figure 26.1?
A) A
B) B
C) C
D) D
E) E

If Figure 26.1 is an accurate depiction of relatedness, then which of the following should be correct?

1. The entire tree is based on maximum parsimony.
2. If all species depicted here make up a taxon, this taxon is monophyletic.
3. The last common ancestor of species B and C occurred more recently than the last common ancestor of species D and E.
4. Species A is the direct ancestor of both species B and species C.
5. The species present at position 3 is ancestral to C, D, and E.

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

Traditionally, whales and hippopotamuses have been classified in different orders, the Cetacea and the Artiodactyla, respectively. Recent molecular evidence, however, indicates that the whales' closest living relatives are the hippos. This has caused some zoologists to lump the two orders together into a single clade, the Cetartiodactyla. There is no consensus on whether the Cetartiodactyla should be accorded order status or superorder status. This is because it remains unclear whether the whale lineage diverged from the lineage leading to the hippos before or after the other members of the order Artiodactyla (pigs, camels, etc.) diverged (see Figure 26.2).

Figure 26.2 contrasts the "Within the artiodactyls" origin of the whale lineage with the "Without the artiodactyls" origin of the whale lineage

If it turns out that the whale lineage diverged from the lineage leading to hippos after the divergence of the lineage leading to the pigs and other artiodactyls, and if the whales continue to be classified in the order Cetacea, then what becomes true of the order Artiodactyla?

A) It becomes monophyletic.
B) It becomes paraphyletic.
C) It becomes polyphyletic.
D) It is incorporated into the order Cetacea

Traditionally, whales and hippopotamuses have been classified in different orders, the Cetacea and the Artiodactyla, respectively. Recent molecular evidence, however, indicates that the whales' closest living relatives are the hippos. This has caused some zoologists to lump the two orders together into a single clade, the Cetartiodactyla. There is no consensus on whether the Cetartiodactyla should be accorded order status or superorder status. This is because it remains unclear whether the whale lineage diverged from the lineage leading to the hippos before or after the other members of the order Artiodactyla (pigs, camels, etc.) diverged (see Figure 26.2).

Figure 26.2 contrasts the "Within the artiodactyls" origin of the whale lineage with the "Without the artiodactyls" origin of the whale lineage

If it turns out that the whale lineage diverged from the lineage leading to hippos after the divergence of the lineage leading to the pigs and other artiodactyls, and if the whales continue to be classified in the order Cetacea, then what becomes true of the taxon Cetartiodactyla?

A) It should be considered as one monophyletic order.
B) It should be considered a superorder that consists of two monophyletic orders.
C) It should be established as a paraphyletic order.
D) It should be thrown out or modified by taxonomists if classification is to reflect evolutionary history.

Traditionally, whales and hippopotamuses have been classified in different orders, the Cetacea and the Artiodactyla, respectively. Recent molecular evidence, however, indicates that the whales' closest living relatives are the hippos. This has caused some zoologists to lump the two orders together into a single clade, the Cetartiodactyla. There is no consensus on whether the Cetartiodactyla should be accorded order status or superorder status. This is because it remains unclear whether the whale lineage diverged from the lineage leading to the hippos before or after the other members of the order Artiodactyla (pigs, camels, etc.) diverged (see Figure 26.2).

Figure 26.2 contrasts the "Within the artiodactyls" origin of the whale lineage with the "Without the artiodactyls" origin of the whale lineage

One morphological feature of modern cetaceans is a vestigial pelvic girdle. If it is determined that cetacean lineage diverged from the artiodactyls' lineage after the divergence of pigs and other artiodactyla, then what should be true of the vestigial pelvic girdle of cetaceans?

A) It should be considered a shared ancestral character of the cetartiodactyls.
B) It should be considered a shared derived character of the cetartiodactyls.
C) It should be considered a shared ancestral character of the cetaceans.
D) It should be considered a shared derived character of the cetaceans.

Traditionally, whales and hippopotamuses have been classified in different orders, the Cetacea and the Artiodactyla, respectively. Recent molecular evidence, however, indicates that the whales' closest living relatives are the hippos. This has caused some zoologists to lump the two orders together into a single clade, the Cetartiodactyla. There is no consensus on whether the Cetartiodactyla should be accorded order status or superorder status. This is because it remains unclear whether the whale lineage diverged from the lineage leading to the hippos before or after the other members of the order Artiodactyla (pigs, camels, etc.) diverged (see Figure 26.2).

Figure 26.2 contrasts the "Within the artiodactyls" origin of the whale lineage with the "Without the artiodactyls" origin of the whale lineage

It was once thought that cetaceans had evolved from an extinct group of mammals called the mesonychids. If, in the future, it is determined that some organisms currently classified as cetaceans did actually evolve from mesonychids, whereas other cetaceans evolved from artiodactyl stock, then what will be true of the order Cetacea?
A) It will be paraphyletic.
B) It will be polyphyletic.
C) It will need to be thrown out or modified if classification is to reflect evolutionary history.
D) Two of the responses are correct.

Figure 26.5. Humans, chimpanzees, gorillas, and orangutans are members of a clade called the great apes, which shared a common ancestor about 18 million years ago (Figure 26.4). Gibbons and siamangs comprise a clade called the lesser apes. Tree-branch lengths indicate elapsed time.

The great apes comprise the family Hominidae, whereas the lesser apes comprise the family Hylobatidae. If the extant organisms on the far right side of Figure 26.5 comprise the next-most exclusive (i.e., specific) taxon, then they comprise different
A) subspecies.
B) species.
C) genuses.
D) genera.
E) orders.

Figure 26.5. Humans, chimpanzees, gorillas, and orangutans are members of a clade called the great apes, which shared a common ancestor about 18 million years ago (Figure 26.4). Gibbons and siamangs comprise a clade called the lesser apes. Tree-branch lengths indicate elapsed time.

Assuming chimps and gorillas are humans' closest relatives, removing humans from the great ape clade and placing them in a different clade has the effect of making the phylogenetic tree of the great apes
A) polyphyletic.
B) paraphyletic.
C) monophyletic.
D) conform with Linnaeus' view of great ape phylogeny.

Traditionally, zoologists have placed birds in their own class, Aves. More recently, molecular evidence has shown that birds are more closely related to reptiles than their anatomy reveals. Genetically, birds are more closely related to crocodiles than crocodiles are to turtles. Thus, bird anatomy has become highly modified as they have adapted to flight, without their genes having undergone nearly as much change.

62) Taxonomically, what should be done with the birds?
A) The traditional stance is correct. Such dramatic morphological change as undergone by birds merits that the birds be placed in their own order, separate from the reptiles.
B) The birds should be reclassified, and their new taxon should be the subclass Aves. Genetic similarity trumps morphological dissimilarity.
C) The rest of the reptiles should be reclassified as a subclass within the class Aves.
D) Science is consensual. Taxonomy is a science. Variant classification schemes involving the birds should be tolerated until consensus is reached.

Traditionally, zoologists have placed birds in their own class, Aves. More recently, molecular evidence has shown that birds are more closely related to reptiles than their anatomy reveals. Genetically, birds are more closely related to crocodiles than crocodiles are to turtles. Thus, bird anatomy has become highly modified as they have adapted to flight, without their genes having undergone nearly as much change.

64) For a proponent of PhyloCode classification, what is true of the reptile clade if birds are not included in it?
A) It becomes paraphyletic and, thus, an invalid reflection of evolutionary history.
B) It becomes a subclass, instead of a class.
C) It becomes a superclass, whereas the birds remain a class.
D) PhyloCode does not concern itself with what is, or is not, a clade.

The next question refer to the following table, which compares the % sequence homology of four different parts (two introns and two exons) of a gene that is found in five different eukaryotic species. Each part is numbered to indicate its distance from the promoter (e.g., Intron I is the one closest to the promoter). The data reported for species A were obtained by comparing DNA from one member of species A to another member of species A.

65) Based on the tabular data, and assuming that time advances vertically, which cladogram (a type of phylogenetic tree) is the most likely depiction of the evolutionary relationships among these five species?

A. SEE IMAGE
B. SEE IMAGE
C. SEE IMAGE
D. SEE IMAGE

Three living species X, Y, and Z share a common ancestor T, as do extinct species U and V. A grouping that consists of species T, X, Y, and Z (but not U or V) makes up
A) a valid taxon.
B) a monophyletic clade.
C) an ingroup, with species U as the outgroup.
D) a paraphyletic group.
E) a polyphyletic group.

In a comparison of birds and mammals, having four limbs is
A) a shared ancestral character.
B) a shared derived character.
C) a character useful for distinguishing birds from mammals.
D) an example of analogy rather than homology.
E) a character useful for sorting bird species.

To apply parsimony to constructing a phylogenetic tree,
A) choose the tree that assumes all evolutionary changes are equally probable.
B) choose the tree in which the branch points are based on as many shared derived characters as possible.
C) base phylogenetic trees only on the fossil record, as this provides the simplest explanation for evolution.
D) choose the tree that represents the fewest evolutionary changes, either in DNA sequences or morphology.
E) choose the tree with the fewest branch points.

72) Based on this tree, which statement is not correct?

A) The salamander lineage is a basal taxon.
B) Salamanders are a sister group to the group containing lizards, goats, and humans.
C) Salamanders are as closely related to goats as to humans.
D) Lizards are more closely related to salamanders than to humans.

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.

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.

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, what is the correct sequence of structures penetrated by B. bacteriophorus on its way to the prey's cytoplasm?

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

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

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
2. endospore
3. fimbriae
4. plasmids

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

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

A) 1 and 2
B) 1 and 3
C) 2 and 3
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 "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.

Which of the following is an important source of endotoxin in gram-negative species?
A) endospore
B) sex pilus
C) flagellum
D) cell wall
E) capsule

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.

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 true?
A) Genetic prospecting has recently revealed the existence of many previously unknown archaean species.
B) No archaeans can reduce CO₂ to methane.
C) The genomes of archaeans are unique, containing no genes that originated within bacteria.
D) No archaeans can inhabit solutions that are nearly 30% salt.
E) No archaeans are adapted to waters with temperatures above the boiling point.

Which of the following traits do archaeans and bacteria share?
1. composition of the cell wall
2. presence of plasma membrane
3. lack of a nuclear envelope
4. identical rRNA sequences

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

A fish that has 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. cells containing 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, and 5
D) 3, 4, and 5
E) 2, 3, 4, and 5

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.

In general, 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

In a hypothetical situation, a bacterium lives on the surface of a leaf, where it obtains nutrition from the leaf's nonliving, waxy covering while inhibiting the growth of other microbes that are plant pathogens. If this bacterium gains access to the inside of a leaf, however, it causes a fatal disease in the plant. Once the plant dies, the bacterium and its offspring decompose the plant. What is the correct sequence of ecological roles played by the bacterium in the situation described here? Use only those that apply.
1. nutrient recycler
2. mutualist
3. commensal
4.parasite
5. primary producer

A) 1, 3, 4
B) 2, 3, 4
C) 2, 4, 1
D) 1, 2, 5
E) 1, 2, 3

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 and nutrients.

Figure 27.2 depicts changes to the amount of DNA present in a recipient cell that is engaged in conjugation with an Hfr cell. Hfr cell DNA begins entering the recipient cell at Time A. Assume that reciprocal crossing over occurs (in other words, a fragment of the recipient's chromosome is exchanged for a homologous fragment from the Hfr cell's DNA). Use Figure 27.2 to answer the following question.

Figure 27.2

46) 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 recipient's chromosome
E) reversal of the direction of conjugation

Figure 27.2 depicts changes to the amount of DNA present in a recipient cell that is engaged in conjugation with an Hfr cell. Hfr cell DNA begins entering the recipient cell at Time A. Assume that reciprocal crossing over occurs (in other words, a fragment of the recipient's chromosome is exchanged for a homologous fragment from the Hfr cell's DNA). Use Figure 27.2 to answer the following question.

Figure 27.2

47) 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) Its membrane-bound DNA pumps are inactive

Figure 27.2 depicts changes to the amount of DNA present in a recipient cell that is engaged in conjugation with an Hfr cell. Hfr cell DNA begins entering the recipient cell at Time A. Assume that reciprocal crossing over occurs (in other words, a fragment of the recipient's chromosome is exchanged for a homologous fragment from the Hfr cell's DNA). Use Figure 27.2 to answer the following question.

Figure 27.2

48) 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

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

Figure 27.2 depicts changes to the amount of DNA present in a recipient cell that is engaged in conjugation with an Hfr cell. Hfr cell DNA begins entering the recipient cell at Time A. Assume that reciprocal crossing over occurs (in other words, a fragment of the recipient's chromosome is exchanged for a homologous fragment from the Hfr cell's DNA). Use Figure 27.2 to answer the following question.

Figure 27.2

49) During which two times can the recipient accurately be described as "recombinant" 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

Figure 27.2 depicts changes to the amount of DNA present in a recipient cell that is engaged in conjugation with an Hfr cell. Hfr cell DNA begins entering the recipient cell at Time A. Assume that reciprocal crossing over occurs (in other words, a fragment of the recipient's chromosome is exchanged for a homologous fragment from the Hfr cell's DNA). Use Figure 27.2 to answer the following question.

Figure 27.2

50) 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 recipient's chromosome, what prevents this from occurring?
B) What forces are generally responsible for disrupting the sex pilus?
C) How is it that a recipient cell does not necessarily become an Hfr cell as the result of conjugation with an Hfr cell?
D) What makes a cell an Hfr cell?

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.

53) This bacterium's ability to survive in a human who is taking penicillin pills may be due to the presence of
1. penicillin-resistance genes
2. a secretory system that removes penicillin from the cell
3. a gram-positive cell wall
4. a gram-negative cell wall
5. an endospore

A) 1 or 5
B) 2 or 3
C) 4 or 5
D) 2, 3, or 5
E) 2, 4, or 5

The following table depicts characteristics of five prokaryotic species (A—E). Use the information in the table to answer the following question.

Gram-variable prokaryotes are, sometimes, those without any peptidoglycan. Which two species are most likely to be archaeans?
A) species A and B
B) species A and C
C) species B and E
D) species C and D
E) species C and E

Bacteria perform each of the following ecological roles. Which role typically does not involve a symbiosis?
A) skin commensalist
B) decomposer
C) aggregates with methane-consuming archaea
D) gut mutualist
E) pathogen

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

Biologists have long been aware that the defunct kingdom Protista is polyphyletic. Which of these statements is most 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 more than once among the protists.
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.

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

Which two genera have members that can evade the human immune system by frequently changing their surface proteins?

1. Plasmodium
2. Trichomonas
3. Paramecium
4. Trypanosoma
5. Entamoeba

A) 1 and 2
B) 1 and 4
C) 2 and 3
D) 2 and 4
E) 4 and 5

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 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.

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

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

A snail-like, coiled, porous test (shell) of calcium carbonate is characteristic of which group?
A) diatoms
B) foraminiferans
C) radiolarians
D) gymnamoebas

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

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.

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 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.

If the Archaeplastidae are eventually designated a kingdom, and if land plants are excluded from this kingdom, then what will be true of this new kingdom?
A) It will be monophyletic.
B) It will more accurately depict evolutionary relationships than does the current taxonomy.
C) It will be paraphyletic.
D) It will be a true clade.
E) It will be polyphyletic.

Which of the following statements concerning protists is true?
A) All protists have mitochondria, though in some species they are much reduced and known by different names.
B) The primary organism that transmits malaria to humans by its bite is the tsetse fly.
C) All apicomplexans are autotrophic.
D) All slime molds have an amoeboid stage that may be followed by a stage during which spores are produced.
E) Euglenozoans that are mixotrophic lack functional chloroplasts.

Which of the following is correctly described as a primary producer?
A) oomycete
B) kinetoplastid
C) apicomplexan
D) diatom
E) radiolarian

You are given the task of designing an aerobic, mixotrophic protist that can perform photosynthesis in fairly deep water (for example, 250 m deep), and can also crawl about and engulf small particles. With which two of the following structures would you provide your protist?

1. hydrogenosome
2. apicoplast
3. pseudopods
4. chloroplast from red alga
5. chloroplast from green alga

A) 1 and 2
B) 2 and 3
C) 2 and 4
D) 3 and 4
E) 4 and 5

You are given the task of designing an aquatic protist that is a primary producer. It cannot swim on its own, yet must stay in well-lit surface waters. It must be resistant to physical damage from wave action. It should be most similar to a(n)
A) diatom.
B) dinoflagellate.
C) apicomplexan.
D) red alga.
E) radiolarian.

A gelatinous seaweed that grows in shallow, cold water and undergoes heteromorphic alternation of generations is most probably what type of alga?
A) red
B) green
C) brown
D) yellow

Living diatoms contain brownish plastids. If global warming causes blooms of diatoms in the surface waters of Earth's oceans, how might this be harmful to the animals that build coral reefs?
A) The coral animals, which capture planktonic organisms, may be outcompeted by the diatoms.
B) The coral animals' endosymbiotic dinoflagellates may get "shaded out" by the diatoms.
C) The coral animals may die from overeating the plentiful diatoms, with their cases of silica.
D) The diatoms' photosynthetic output may over-oxygenate the water.

Giardia lamblia is an intestinal parasite of humans and other mammals that causes intestinal ailments in most people who ingest the cysts. Upon ingestion, each cyst releases two motile cells, called trophozoites. These attach to the small intestine's lining via a ventral adhesive disk. The trophozoites anaerobically metabolize glucose from the host's intestinal contents to produce ATP. Reproduction is completely asexual, occurring by longitudinal binary fission of trophozoites, with each daughter cell receiving two, haploid nuclei (n = 5). A trophozoite will often encyst as it passes into the large intestine by secreting around itself a case that is resistant to cold, heat, and dehydration. Infection usually occurs by drinking untreated water that contains cysts.

47) Given the putative ancestry of Giardia's mitosome, what should we predict is true of the mitosome?
A) It has electron transport systems that use oxygen as the final electron acceptor.
B) It has a double membrane.
C) It has thylakoids.
D) It contains microtubules, arranged in the "9 + 2 pattern."
E) It contains 80S (eukaryotic) ribosomes.

Giardia lamblia is an intestinal parasite of humans and other mammals that causes intestinal ailments in most people who ingest the cysts. Upon ingestion, each cyst releases two motile cells, called trophozoites. These attach to the small intestine's lining via a ventral adhesive disk. The trophozoites anaerobically metabolize glucose from the host's intestinal contents to produce ATP. Reproduction is completely asexual, occurring by longitudinal binary fission of trophozoites, with each daughter cell receiving two, haploid nuclei (n = 5). A trophozoite will often encyst as it passes into the large intestine by secreting around itself a case that is resistant to cold, heat, and dehydration. Infection usually occurs by drinking untreated water that contains cysts.

52) The cysts of Giardia are most analogous to the
A) mitochondria of ancestral diplomonads.
B) nuclei of archaeans.
C) endospores of bacteria.
D) capsids of viruses.

Paulinella chromatophora is one of the few cercozoans that is autotrophic, carrying out aerobic photosynthesis with its two elongated "cyanelles." The cyanelles are contained within vesicles of the host cell, and each is derived from a cyanobacterium, though not the same type of cyanobacterium that gave rise to the chloroplasts of algae and plants.

55) The closest living relative of P. chromatophora is the heterotroph, P. ovalis. What type of evidence permits biologists to make this claim about relatedness?
A) morphological
B) ecological
C) biochemical
D) genetic
E) fossil

Paulinella chromatophora is one of the few cercozoans that is autotrophic, carrying out aerobic photosynthesis with its two elongated "cyanelles." The cyanelles are contained within vesicles of the host cell, and each is derived from a cyanobacterium, though not the same type of cyanobacterium that gave rise to the chloroplasts of algae and plants.

56) The closest living relative of P. chromatophora is the heterotroph, P. ovalis. P. ovalis uses threadlike pseudopods to capture its prey, which it digests internally. Which of the following, if observed, would be the best reason for relabeling P. chromatophora as a mixotroph?
A) a threadlike pseudopod
B) a pigmented central vacuole, surrounded by a tonoplast
C) a vacuole with food inside
D) a secretory vesicle
E) a contractile vacuole

Paulinella chromatophora is one of the few cercozoans that is autotrophic, carrying out aerobic photosynthesis with its two elongated "cyanelles." The cyanelles are contained within vesicles of the host cell, and each is derived from a cyanobacterium, though not the same type of cyanobacterium that gave rise to the chloroplasts of algae and plants.

57) P. chromatophora secretes around itself a test, or case, of plates made of silica. Which of the following is another rhizarian that would be in competition with P. chromatophora for the silica needed to make these plates, assuming limited quantities of silica in the environment?
A) radiolarians
B) foraminiferans
C) all other amoeboid cells
D) all other rhizaria
E) diatoms

Paulinella chromatophora is one of the few cercozoans that is autotrophic, carrying out aerobic photosynthesis with its two elongated "cyanelles." The cyanelles are contained within vesicles of the host cell, and each is derived from a cyanobacterium, though not the same type of cyanobacterium that gave rise to the chloroplasts of algae and plants.

58) Which of the following represents the true significance of the finding that the cyanelles of P. chromatophora stem from a different type of cyanobacterium than gave rise to chloroplasts?
A) This finding indicates that there is a second evolutionary lineage of photosynthetic eukaryotes.
B) This finding represents the first time that primary endosymbiosis has been directly observed.
C) This finding is the strongest evidence yet for the theory of endosymbiosis.
D) This finding is an example of the phenomenon known as "serial endosymbiosis."
E) This finding is the first evidence that eukaryotic cells do not necessarily digest prokaryotic cells that manage to gain access to their cytoplasm.

Paulinella chromatophora is one of the few cercozoans that is autotrophic, carrying out aerobic photosynthesis with its two elongated "cyanelles." The cyanelles are contained within vesicles of the host cell, and each is derived from a cyanobacterium, though not the same type of cyanobacterium that gave rise to the chloroplasts of algae and plants.

59) The genome of modern chloroplasts is roughly 50% the size of the genome of the cyanobacterium from which it is thought to have been derived. In comparison, the genome of P. chromatophora's cyanelle is only slightly reduced relative to the size of the genome of the cyanobacterium from which it is thought to have been derived. What is a valid conclusion that can be drawn from this comparison?
A) Lytic phage infections have targeted the chloroplast genome more often than the P. chromatophora genome.
B) P. chromatophora's cyanelle is the result of an evolutionarily recent endosymbiosis.
C) The genome of the chloroplast ancestor contained many more introns that could be lost without harm, compared to the cyanelle's genome.
D) All three of the conclusions above are valid.
E) Two of the conclusions above are valid.

Paulinella chromatophora is one of the few cercozoans that is autotrophic, carrying out aerobic photosynthesis with its two elongated "cyanelles." The cyanelles are contained within vesicles of the host cell, and each is derived from a cyanobacterium, though not the same type of cyanobacterium that gave rise to the chloroplasts of algae and plants.

60) If true, which of the following would be most important in determining whether P. chromatophora's cyanelle is still an endosymbiont, or is an organelle, as the term cyanelle implies?
A) If P. chromatophora is less fit without its cyanelle than with it.
B) If the cyanelle is less fit without the host cercozoan than with it.
C) If there is ongoing metabolic cooperation between the cyanelle and the host cercozoan.
D) If the magnesium-containing porphyrin ring in the cyanelle's chlorophyll molecules is built by the cyanelle, whereas the organic portion of the chlorophyll molecules is built by the host cercozoan.
E) If there has been movement of genes from the cyanelle genome to the nuclear genome, such that these genes are no longer present in the cyanelle genome.

Healthy individuals of Paramecium bursaria contain photosynthetic algal endosymbionts of the genus Chlorella. When within their hosts, the algae are referred to as zoochlorellae. In aquaria with light coming from only one side, P. bursaria gathers at the well-lit side, whereas other species of Paramecium gather at the opposite side. The zoochlorellae provide their hosts with glucose and oxygen, and P. bursaria provides its zoochlorellae with protection and motility. P. bursaria can lose its zoochlorellae in two ways: (1) if kept in darkness, the algae will die; and (2) if prey items (mostly bacteria) are absent from its habitat, P. bursaria will digest its zoochlorellae.

65) Which term most accurately describes the nutritional mode of healthy P. bursaria?
A) photoautotroph
B) photoheterotroph
C) chemoheterotroph
D) chemoautotroph
E) mixotroph

Healthy individuals of Paramecium bursaria contain photosynthetic algal endosymbionts of the genus Chlorella. When within their hosts, the algae are referred to as zoochlorellae. In aquaria with light coming from only one side, P. bursaria gathers at the well-lit side, whereas other species of Paramecium gather at the opposite side. The zoochlorellae provide their hosts with glucose and oxygen, and P. bursaria provides its zoochlorellae with protection and motility. P. bursaria can lose its zoochlorellae in two ways: (1) if kept in darkness, the algae will die; and (2) if prey items (mostly bacteria) are absent from its habitat, P. bursaria will digest its zoochlorellae.

66) Which term accurately describes the behavior of Paramecium species that lack zoochlorellae in an aquarium with light coming from one side only?
A) positive chemotaxis
B) negative chemotaxis
C) positive phototaxis
D) negative phototaxis

Healthy individuals of Paramecium bursaria contain photosynthetic algal endosymbionts of the genus Chlorella. When within their hosts, the algae are referred to as zoochlorellae. In aquaria with light coming from only one side, P. bursaria gathers at the well-lit side, whereas other species of Paramecium gather at the opposite side. The zoochlorellae provide their hosts with glucose and oxygen, and P. bursaria provides its zoochlorellae with protection and motility. P. bursaria can lose its zoochlorellae in two ways: (1) if kept in darkness, the algae will die; and (2) if prey items (mostly bacteria) are absent from its habitat, P. bursaria will digest its zoochlorellae.

67) Which term best describes the symbiotic relationship of well-fed P. bursaria to their zoochlorellae?
A) mutualistic
B) commensal
C) parasitic
D) predatory
E) pathogenic

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

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.

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) rings of 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 generations.
E) scientists have no evidence to indicate whether or not land plants evolved from any kind of alga.

Which taxon is essentially equivalent to the "embryophytes"?
A) Viridiplantae
B) Plantae
C) Pterophyta
D) Bryophyta
E) Charophycea

A student encounters a pondweed which, judging from its appearance, seems to be a charophyte. She brings a sample back to her biology lab. Using only a compound light microscope to study the sample, which of the following features should help her to determine whether the sample comes from a charophyte or from some other type of green alga?

1. molecular structure of enzymes inside peroxisomes
2. structure of sperm cells
3. presence of phragmoplasts
4. rings of cellulose-synthesizing complexes

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

What is true of charophytes?
A) They are the ancestors of green algae.
B) They are examples of seedless vascular plants.
C) They are the closest living algal relatives of land plants.
D) They share some features in common with land plants, namely spores surrounded by sporopollenin and alternation of generations.

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.

If the kingdom Plantae is someday expanded to include the charophytes, then the shared derived characteristics of the kingdom will include

1. rings of cellulose-synthesizing complexes.
2. chlorophylls a and b.
3. alternation of generations.
4. cell walls of cellulose.
5. ability to synthesize sporopollenin.

A) 1 and 5
B) 1, 2, and 3
C) 1, 3, and 5
D) 1, 4, and 5
E) 1, 2, 4, and 5

Mitotic activity by the apical meristem of a root makes which of the following more possible?
A) increase of the aboveground stem.
B) decreased absorption of mineral nutrients.
C) increased absorption of COâ‚‚.
D) increased number of chloroplasts in roots.
E) effective lateral growth of the stem.

Which of the following statements is true of archegonia?
A) They are the sites where male gametes are produced.
B) They may temporarily contain sporophyte embryos.
C) They are the same as sporangia.
D) They are the ancestral versions of animal gonads.
E) They are asexual reproductive structures.

Which of the following is a true statement about plant reproduction?
A) Embryophytes are small because they are in an early developmental stage.
B) Both male and female bryophytes produce gametangia.
C) Gametangia protect gametes from excess water.
D) Eggs and sperm of bryophytes swim toward one another.
E) Bryophytes are limited to asexual reproduction.

Assuming that they all belong to the same plant, arrange the following structures from largest to smallest.

1. antheridia
2. gametes
3. gametophytes
4. gametangia

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

The leaflike appendages of moss gametophytes may be one to two cell layers thick. Consequently, which of the following is least likely to be found associated with such appendages?
A) cuticle
B) rings of cellulose-synthesizing complexes
C) stomata
D) peroxisomes
E) phenolics

As is true of the gametophytes of all land plants, the gametophytes of true mosses lack stomata. Yet, the feather moss Pleurozium harbors nitrogen-fixing cyanobacteria. Which of the following is a feature of moss gametophytes that is most important for the continued survival of these cyanobacteria in the tissues of the feather moss gametophyte?
A) lack of cuticle
B) lack of vascular tissues
C) lack of true leaves or roots
D) lack of an independent sporophyte
E) lack of multiple cell layers in "leaves" of "buds"

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.

At some time during their existence, bryophytes may feature
A) microphylls.
B) true roots.
C) true leaves.
D) sporangia.
E) umbilical cells.

If you are looking for structures that transfer water and nutrients from a bryophyte gametophyte to a bryophyte sporophyte, then on which part of the sporophyte should you focus your attention?
A) spores
B) seta
C) foot
D) sporangium
E) peristome

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

If a fern gametophyte is a hermaphrodite (that is, has both male and female gametangia on the same plant), then it
A) belongs to a species that is homosporous.
B) must be diploid.
C) has lost the need for a sporophyte generation.
D) has antheridia and archegonia combined into a single sex organ.
E) is actually not a fern, because fern gametophytes are always either male or female.

Assuming that they all belong to the same plant, arrange the following structures from largest to smallest (or from most inclusive to least inclusive).

1. spores
2. sporophylls
3. sporophytes
4. sporangia

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

Arrange the following terms from most inclusive to least inclusive.

1. embryophytes
2. green plants
3. seedless vascular plants
4. ferns
5. tracheophytes

A) 1, 2, 5, 3, 4
B) 2, 1, 5, 3, 4
C) 2, 5, 1, 3, 4
D) 1, 4, 2, 5, 3
E) 2, 1, 5, 4, 3

Increasing the number of stomata per unit surface area of a leaf when atmospheric COâ‚‚ levels decline is most analogous to a human
A) breathing faster as atmospheric COâ‚‚ levels increase.
B) putting more red blood corpuscles (RBCs) into circulation when atmospheric Oâ‚‚ levels decline.
C) removing RBCs from circulation when atmospheric Oâ‚‚ levels increase.
D) breathing more slowly as atmospheric Oâ‚‚ levels increase.

Which of the following should have had gene sequences most similar to the charophyte that was the common ancestor of the land plants?
A) early angiosperms
B) early bryophytes
C) early gymnosperms
D) early lycophytes
E) early pterophytes

Of the following list, flagellated (swimming) sperm are generally present in which groups?

1. Lycophyta
2. Bryophyta
3. Angiosperms
4. Chlorophyta
5. Pterophyta

A) 1, 2, and 3
B) 1, 2, 4, and 5
C) 1, 3, 4, and 5
D) 2, 3, and 5
E) 2, 3, 4, and 5

If intelligent extraterrestrials visited Earth 475 million years ago, and then again 300 million years ago (at the close of the Carboniferous period), what trends would they have noticed in Earth's terrestrial vegetation over this period?

1.a trend from dominant gametophytes to dominant sporophytes
2. a trend from sporangia borne on modified leaves (sporophylls) to sporangia borne on stalks (seta)
3. a trend from no true leaves, to microphylls, to megaphylls
4. a trend from soil-surface-hugging plants to "overtopping" plants
5. a trend toward increased lignification of conducting systems

A) 1 and 3
B) 3, 4, and 5
C) 1, 2, 4, and 5
D) 1, 3, 4, and 5
E) 2, 3, 4, and 5

During glacial periods in the early evolution of land plants, which of the following would have been a beneficial adaptation regarding the number of stomata per unit surface area, and what accounts for it?
A) increased numbers of stomata, to maximize absorption of increasing levels of atmospheric COâ‚‚
B) increased numbers of stomata, to maximize ability to absorb low levels of atmospheric COâ‚‚
C) decreased numbers of stomata, to retain COâ‚‚ produced by the chloroplasts
D) decreased numbers of stomata, to maximize absorption of low levels of atmospheric COâ‚‚

Researchers decided to test the hypothesis that if the 2-m tall Polytrichum gametophyte-sporophyte plants had acted as a physical buffer, then they would have reduced water's ability to erode the soil and carry away its nitrogen. They began with four equal-sized areas where Polytrichum mosses grew to a height of 2 m above the soil surface. One of the four areas was not modified. In the second area, the mosses were trimmed to a height of 1 m above the soil surface. In the third area, the mosses were trimmed to a height of 0.5 m above the soil surface. In the fourth area, the mosses were trimmed all the way to the ground, leaving only the rhizoids. Water, simulating rainfall, was then added in a controlled fashion to all plots over the course of one year. Figure 29.2 presents four graphs that depict potential results of this experiment.

54) The 2-m height attainable by Polytrichum moss is at the upper end of the size range reached by mosses. What accounts for the relative tallness of Polytrichum?
A) the cuticle that is found along the ridges of "leaves"
B) "leaves" that are more than one cell layer thick
C) high humidity of surrounding air which provides support against gravity
D) reduced size, mass, and persistence of the sporophytes which allows gametophores to grow taller
E) the presence of conducting tissues in the "stem"

Big Bend National Park in Texas is mostly Chihuahuan desert, where rainfall averages about 10 inches per year. Yet, it is not uncommon when hiking in this bone-dry desert to encounter mosses and ferns. One such plant is called "flower of stone." It is not a flowering plant, nor does it produce seeds. Under arid conditions, its leaflike structures curl up. However, when it rains, it unfurls its leaves, which form a bright green rosette on the desert floor. Consequently, it is sometimes called the "resurrection plant." At first glance, it could be a fern, a true moss, or a spike moss.

64) Which of the following characteristics is (are) possessed in common by true mosses, ferns, and spike mosses, and therefore becomes useless at helping to determine to which of these groups flower of stone belongs?

1. a sporophyte generation that is dominant
2. true leaves and roots
3. flagellated sperm
4. strobili
5. alternation of generations

A) 5 only
B) 1 and 5
C) 2 and 3
D) 3 and 5
E) 2, 4, and 5

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

Which of the following characteristics of plants is absent in their closest relatives, the charophyte algae?
A) chlorophyll b
B) cellulose in cell walls
C) formation of a cell plate during cytokinesis
D) sexual reproduction
E) alternation of multicellular generations

Microphylls are found in which plant group?
A) mosses
B) liverworts
C) lycophytes
D) ferns
E) hornworts

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

Suppose an efficient conducting system evolved in a moss that could transport water and other materials as high as a tall tree. Which of the following statements about "trees" of such a species would not be true?
A) Fertilization would probably be more difficult.
B) Spore dispersal distances would probably increase.
C) Females could produce only one archegonium.
D) Unless its body parts were strengthened, such a "tree" would probably flop over.
E) Individuals would probably compete more effectively for access to light.

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.

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.

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

In seed plants, which of the following is part of a pollen grain and has a function most like that of the seed coat?
A) sporophyll
B) male gametophyte
C) sporopollenin
D) stigma
E) sporangium

Generally, wind pollination is most likely to be found in seed plants that grow
A) close to the ground.
B) in dense, single-species stands.
C) in relative isolation from other members of the same species.
D) along coastlines where prevailing winds blow from the land out to sea.
E) in well-drained soils.

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.

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.

Arrange the following structures, which can be found on male pine trees, from the largest structure to the smallest structure (or from most inclusive to least inclusive).

1. sporophyte
2. microspores
3. microsporangia
4. pollen cone
5. pollen nuclei

A) 1, 4, 3, 2, 5
B) 1, 4, 2, 3, 5
C) 1, 2, 3, 5, 4
D) 4, 1, 2, 3, 5
E) 4, 3, 2, 5, 1

Which trait(s) is (are) shared by many modern gymnosperms and angiosperms?

1. pollen transported by wind
2. lignified xylem
3. microscopic gametophytes
4. sterile sporophylls, modified to attract pollinators
5. endosperm

A) 1 only
B) 1 and 3
C) 1, 2, and 3
D) 1, 3, and 5
E) 2, 4, and 5

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

Reptilian embryos are protected from desiccation by a leathery shell. Similarly, which pair of structures protects seed plants' embryos and male gametophytes, respectively, from desiccation?
A) ovuleswaxy cuticle
B) ovariesfilaments
C) fruitsstamens
D) pollen grainswaxy cuticle
E) integumentssporopollenin

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

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

Given the differences between angiosperms and gymnosperms in the development of the integument(s), which of these statements is the most logical consequence?
A) The seed coats of angiosperms should be relatively thicker than those of gymnosperms.
B) It should be much more difficult for pollen tubes to enter angiosperm ovules than for them to enter gymnosperm ovules.
C) The female gametophytes of angiosperms should not be as well protected from environmental stress as should those of gymnosperms.
D) As a direct consequence of such differences, angiosperms should have fruit.
E) Angiosperm seeds should be more susceptible to desiccation.

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

What adaptations should one expect of the seed coats of angiosperm species whose seeds are dispersed by frugivorous (fruit-eating) animals, as opposed to angiosperm species whose seeds are dispersed by other means?

1. The exterior of the seed coat should have barbs or hooks.
2. The seed coat should contain secondary compounds that irritate the lining of the animal's mouth.
3. The seed coat should be able to withstand low pH's.
4. The seed coat, upon its complete digestion, should provide vitamins or nutrients to animals.
5. The seed coat should be resistant to the animals' digestive enzymes.

A) 4 only
B) 1 and 2
C) 2 and 3
D) 3 and 5
E) 3, 4, and 5

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

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.

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

Among plants known as legumes (beans, peas, alfalfa, clover, etc.) the seeds are contained in a fruit that is itself called a legume, better known as a pod. Upon opening such pods, it is commonly observed that some ovules have become mature seeds, whereas other ovules have not. Thus, which of the following statements is (are) true?

1. The flowers that gave rise to such pods were not pollinated.
2. Pollen tubes did not enter all of the ovules in such pods.
3. There was apparently not enough endosperm to distribute to all of the ovules in such pods.
4. The ovules that failed to develop into seeds were derived from sterile floral parts.
5. Fruit can develop, even if all ovules within have not been fertilized.

A) 1 only
B) 1 and 5
C) 2 and 4
D) 2 and 5

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

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.

Hypothetically, one of the major benefits of double fertilization in angiosperms is to
A) decrease the potential for mutation by insulating the embryo with other cells.
B) increase the number of fertilization events and offspring produced.
C) promote diversity in flower shape and color.
D) coordinate developmental timing between the embryo and its food stores.
E) emphasize embryonic survival by increasing embryo size.

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

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

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

In a typical angiosperm, what is the sequence of structures encountered by the tip of a growing pollen tube on its way to the egg?

1. micropyle
2. style
3. ovary
4. stigma

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

The fruit of the mistletoe, a parasitic angiosperm, is a one-seeded berry. In members of the genus Viscum, the outside of the seed is viscous (sticky), which permits the seed to adhere to surfaces, such as the branches of host plants or the beaks of birds. What should be expected of the fruit if the viscosity of Viscum seeds is primarily an adaptation for dispersal rather than an adaptation for infecting host plant tissues?
A) It should be drab in color.
B) It should be colored so as to provide it with camouflage.
C) It should be nutritious.
D) It should secrete enzymes that can digest bark.
E) It should contain chemicals that cause birds to fly to the ground and vomit.

The following questions refer to the generalized life cycle for land plants shown in Figure 30.1. Each number within a circle or square represents a specific plant or plant part, and each number over an arrow represents either meiosis, mitosis, or fertilization.

Figure 30.1

54) In Figure 30.1, which number represents the mature gametophyte?
A) 1
B) 3
C) 5
D) 7
E) 11

The following questions refer to the generalized life cycle for land plants shown in Figure 30.1. Each number within a circle or square represents a specific plant or plant part, and each number over an arrow represents either meiosis, mitosis, or fertilization.

Figure 30.1

55) In Figure 30.1, which number represents an embryo?
A) 1
B) 3
C) 7
D) 9
E) 11

The following questions refer to the generalized life cycle for land plants shown in Figure 30.1. Each number within a circle or square represents a specific plant or plant part, and each number over an arrow represents either meiosis, mitosis, or fertilization.

Figure 30.1

56) Meiosis is most likely to be represented by which number(s) in Figure 30.1?
A) 2
B) 4
C) 2 and 8
D) 4 and 8
E) 10 and 12

The following questions refer to the generalized life cycle for land plants shown in Figure 30.1. Each number within a circle or square represents a specific plant or plant part, and each number over an arrow represents either meiosis, mitosis, or fertilization.

Figure 30.1

57) Which number represents a megaspore mother cell in Figure 30.1?
A) 1
B) 3
C) 5
D) 7
E) 11

The following questions refer to the generalized life cycle for land plants shown in Figure 30.1. Each number within a circle or square represents a specific plant or plant part, and each number over an arrow represents either meiosis, mitosis, or fertilization.

Figure 30.1

58) In Figure 30.1, the process labeled "6" involves
A) nuclear fission.
B) mitosis.
C) meiosis.
D) fertilization.
E) binary fission.

The following questions refer to the generalized life cycle for land plants shown in Figure 30.1. Each number within a circle or square represents a specific plant or plant part, and each number over an arrow represents either meiosis, mitosis, or fertilization.

Figure 30.1

59) The embryo sac of an angiosperm flower is best represented by which number in Figure 30.1?
A) 1
B) 3
C) 7
D) 9

The following questions refer to the generalized life cycle for land plants shown in Figure 30.1. Each number within a circle or square represents a specific plant or plant part, and each number over an arrow represents either meiosis, mitosis, or fertilization.

Figure 30.1

60) In angiosperms, which number in Figure 30.1 most nearly represents the event that initiates the formation of endosperm?
A) 4
B) 6
C) 8
D) 10
E) 12

The cycads, a mostly tropical phylum of gymnosperms, evolved about 300 million years ago and were dominant forms during the Age of the Dinosaurs. Though their sperm are flagellated, their ovules are pollinated by beetles. These beetles get nutrition (they eat pollen) and shelter from the microsporophylls. Upon visiting megasporophylls, the beetles transfer pollen to the exposed ovules. In cycads, pollen cones and seed cones are borne on different plants. Cycads synthesize neurotoxins, especially in the seeds, that are effective against most animals, including humans.

62) Which feature of cycads makes them similar to many angiosperms?

1. They have exposed ovules.
2. They have flagellated sperm.
3. They are pollinated by animals.

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

The cycads, a mostly tropical phylum of gymnosperms, evolved about 300 million years ago and were dominant forms during the Age of the Dinosaurs. Though their sperm are flagellated, their ovules are pollinated by beetles. These beetles get nutrition (they eat pollen) and shelter from the microsporophylls. Upon visiting megasporophylls, the beetles transfer pollen to the exposed ovules. In cycads, pollen cones and seed cones are borne on different plants. Cycads synthesize neurotoxins, especially in the seeds, that are effective against most animals, including humans.

64) On the Pacific island of Guam, large herbivorous bats called "flying foxes" commonly feed on cycad seeds, a potent source of neurotoxins. The flying foxes do not visit male cones. Consequently, what should be true?
A) The flying foxes are attracted to cycad fruit, and eat the enclosed seeds only by accident.
B) Flying foxes are highly susceptible to the effects of the neurotoxins.
C) The flying foxes assist the beetles as important pollinating agents of the cycads.
D) Flying foxes can be dispersal agents of cycad seeds if the seeds sometimes get swallowed whole (in other words, without getting chewed).

Oviparous (egg-laying) animals have internal fertilization (sperm cells encounter eggs within the female's body). Yolk and/or albumen is (are) provided to the embryo, and a shell is then deposited around the embryo and its food source. Eggs are subsequently deposited in an environment that promotes their further development, or are incubated by one or both parents.

74) The internal fertilization that occurs prior to shell deposition is what type of angiosperm analog?
A) endosperm
B) pollen tube and sperm nuclei
C) carpels
D) fruit
E) integuments

Oviparous (egg-laying) animals have internal fertilization (sperm cells encounter eggs within the female's body). Yolk and/or albumen is (are) provided to the embryo, and a shell is then deposited around the embryo and its food source. Eggs are subsequently deposited in an environment that promotes their further development, or are incubated by one or both parents.

75) The dispersal and/or nurture of young after hatching from the egg is what type of angiosperm analog?
A) endosperm
B) pollen tube and sperm nuclei
C) carpels
D) fruit
E) integuments

Harold and Kumar are pre-med and pre-pharmacy students, respectively. They complain to their biology professor that they should not have to study about plants because plants have little relevance to their chosen professions.

77) From reading their biology textbook, what would Harold and Kumar discover?
A) About one-quarter of all prescription drugs come from seed plants.
B) Prescription drugs that enter the water table are responsible for the extinction of many plants.
C) Much of what was once rain forest has been replanted with fields of medicinally valuable plants.
D) All rain forest plants contain at least one chemical useful as a medicine.

The Brazil nut tree, Bertholletia excels (n = 17), is native to tropical rain forests of South America. It is a hardwood tree that can grow to over 50 meters, is a source of high-quality lumber, and is a favorite nesting site for harpy eagles. As the rainy season ends, tough-walled fruits, each containing 825 seeds (Brazil nuts), fall to the forest floor. About $50 million worth of nuts are harvested each year. Scientists have discovered that the pale yellow, self-incompatible flowers of Brazil nut trees admit only female orchid bees as pollinators.

81) The agouti (Dasyprocta spp.), a cat-sized rodent, is the only animal with teeth strong enough to crack the hard wall of Brazil nut fruits. It typically eats some of the seeds, buries others, and leaves still others behind inside the fruit, which moisture can now enter. The uneaten seeds may subsequently germinate. Consequently, which terms describe the relationship between the Brazil nut tree and the agouti?

1. parasitic
2. commensalistic
3. symbiotic
4. endosymbiotic
5. mutualistic

A) 1 and 3
B) 2 and 4
C) 2 and 5
D) 3 and 5
E) 4 and 5

The Brazil nut tree, Bertholletia excels (n = 17), is native to tropical rain forests of South America. It is a hardwood tree that can grow to over 50 meters, is a source of high-quality lumber, and is a favorite nesting site for harpy eagles. As the rainy season ends, tough-walled fruits, each containing 825 seeds (Brazil nuts), fall to the forest floor. About $50 million worth of nuts are harvested each year. Scientists have discovered that the pale yellow, self-incompatible flowers of Brazil nut trees admit only female orchid bees as pollinators.

92) If a female orchid bee has just left a Brazil nut tree with nectar in her stomach, and if she visits another flower on a different Brazil nut tree, what is the sequence in which the following events should occur?

1. double fertilization
2. pollen tube emerges from pollen grain
3. pollen tube enters micropyle
4. pollination

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

100) With respect to angiosperms, which of the following is incorrectly paired with its chromosome count?

A) egg–n
B) megaspore–2n
C) microspore–n
D) zygote–2n
E) sperm–n

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

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

If all fungi in an environment that perform decomposition were to suddenly die, then which group of organisms should benefit most, due to the fact that their fungal competitors have been removed?
A) plants
B) protists
C) prokaryotes
D) animals
E) mutualistic fungi

When a mycelium infiltrates an unexploited source of dead organic matter, what are most likely to appear within the food source soon thereafter?
A) fungal haustoria
B) soredia
C) fungal enzymes
D) increased oxygen levels
E) larger bacterial populations

Which of the following is a characteristic of hyphate fungi (fungi featuring hyphae)?
A) They acquire their nutrients by phagocytosis.
B) Their body plan is a unicellular sphere.
C) Their cell walls consist mainly of cellulose microfibrils.
D) They are adapted for rapid directional growth to new food sources.
E) They reproduce asexually by a process known as budding.

What do fungi and arthropods have in common?
A) Both groups are commonly coenocytic.
B) The haploid state is dominant in both groups.
C) Both groups are predominantly heterotrophs that ingest their food.
D) The protective coats of both groups are made of chitin.
E) Both groups have cell walls.

In septate fungi, what structures allow cytoplasmic streaming to distribute needed nutrients, synthesized compounds, and organelles throughout the hyphae?
A) multiple chitinous layers in cross-walls
B) pores in cross-walls
C) complex microtubular cytoskeletons
D) two nuclei
E) tight junctions that form in cross-walls between cells

What accounts most directly for the extremely fast growth of a fungal mycelium?
A) rapid distribution of synthesized proteins by cytoplasmic streaming
B) a long tubular body shape
C) the readily available nutrients from their ingestive mode of nutrition
D) a dikaryotic condition that supplies greater amounts of proteins and nutrients

Immediately after karyogamy occurs, which term applies?
A) plasmogamy
B) heterokaryotic
C) dikaryotic
D) diploid

Plasmogamy can directly result in which of the following?

1. cells with a single haploid nucleus
2. heterokaryotic cells
3. dikaryotic cells
4. cells with two diploid nuclei

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

In most fungi, karyogamy does not immediately follow plasmogamy, which consequently
A) means that sexual reproduction can occur in specialized structures.
B) results in multiple diploid nuclei per cell.
C) allows fungi to reproduce asexually most of the time.
D) results in heterokaryotic or dikaryotic cells.
E) is strong support for the claim that fungi are not truly eukaryotic.

Which process occurs in fungi and has the opposite effect on a cell's chromosome number than does meiosis I?
A) mitosis
B) plasmogamy
C) crossing over
D) binary fission
E) karyogamy

Which of the following statements is true of deuteromycetes?
A) They are the second of five fungal phyla to have evolved.
B) They represent the phylum in which all the fungal components of lichens are classified.
C) They are the group of fungi that have, at present, no known sexual stage.
D) They are the group that includes molds, yeasts, and lichens.
E) They include the imperfect fungi that lack hyphae.

Fossil fungi date back to the origin and early evolution of plants. What combination of environmental and morphological change is similar in the evolution of both fungi and plants?
A) presence of "coal forests" and change in mode of nutrition
B) periods of drought and presence of filamentous body shape
C) predominance in swamps and presence of cellulose in cell walls
D) colonization of land and loss of flagellated cells
E) continental drift and mode of spore dispersal

Which of the following characteristics is shared by both chytrids and other kinds of fungi?
A) presence of flagella
B) zoospores
C) autotrophic mode of nutrition
D) cell walls of cellulose
E) nucleotide sequences of several genes

The multicellular condition of animals and fungi seems to have arisen
A) due to common ancestry.
B) by convergent evolution.
C) by inheritance of acquired traits.
D) by natural means, and is a homology.
E) by serial endosymbioses.

You are given an organism to identify. It has a fruiting body that contains many structures with eight haploid spores lined up in a row. What kind of a fungus is this?
A) zygomycete
B) ascomycete
C) deuteromycete
D) chytrid
E) basidiomycete

Arrange the following from largest to smallest, assuming that they all come from the same fungus.

1. basidiocarp
2. basidium
3. basidiospore
4. mycelium
5. gill

A) 4 → 5 → 1→ 2 → 3
B) 5 → 1 → 4 → 2 → 3
C) 5 → 1 → 4 → 3 → 2
D) 5 → 1 → 3 → 2 → 4
E) 4 → 1 → 5 → 2 → 3

A fungal spore germinates, giving rise to a mycelium that grows outward into the soil surrounding the site where the spore originally landed. Which of the following accounts for the fungal movement, as described here?
A) karyogamy
B) mycelial flagella
C) alternation of generations
D) breezes distributing spores
E) cytoplasmic streaming in hyphae

) Both fungus-derived antibiotics and hallucinogens used by humans probably evolved in fungi as a means to
A) reduce competition for nutrients.
B) help humanity survive.
C) promote their ingestion of foodstuffs.
D) eliminate other fungi.
E) discourage animal predators.

Orchid seeds are tiny, with virtually no endosperm and with miniscule cotyledons. If such seeds are deposited in a dark, moist environment, then which of the following represents the most likely means by which fungi might assist in seed germination, given what the seeds lack?
A) by transferring some chloroplasts to the embryo in each seed
B) by providing the seeds with water and minerals
C) by providing the embryos with some of the organic nutrients they have absorbed

49) Which tree depicts the microsporidians as a sister group of the ascomycetes?
A) I
B) II
C) III
D) IV

Which tree depicts the microsporidians as a sister group of the fungi, rather than as a fungus?
A) I
B) II
C) III
D) IV

The following figure depicts the outline of a large fairy ring that has appeared overnight in an open meadow, as viewed from above. The fairy ring represents the furthest advance of this mycelium through the soil. Locations AD are all 0.5 meters below the soil surface. Responses may be used once, more than once, or not at all.

52) What is the most probable location of the oldest portion of this mycelium?
A) A
B) B
C) C
D) D

The following figure depicts the outline of a large fairy ring that has appeared overnight in an open meadow, as viewed from above. The fairy ring represents the furthest advance of this mycelium through the soil. Locations AD are all 0.5 meters below the soil surface. Responses may be used once, more than once, or not at all.

54) At which location is the mycelium currently absorbing the most nutrients per unit surface area, per unit time?
A) A
B) B
C) C
D) D

The following figure depicts the outline of a large fairy ring that has appeared overnight in an open meadow, as viewed from above. The fairy ring represents the furthest advance of this mycelium through the soil. Locations AD are all 0.5 meters below the soil surface. Responses may be used once, more than once, or not at all.

57) In which of the following human mycoses should one expect to find a growth pattern most similar to that of the mycelium that produced the fairy ring?
A) skin mycoses
B) coccidiomycosis (lung infection)
C) systemic (bloodborne) Candida infection
D) Sporothrix infection of lymphatic vessels
E) Tinea tonsurans infection limited to interior of hair shafts

Surface area represents the area available for exchange with the environment, whereas volume represents the cytoplasm which requires nutrients and from which waste products (usually toxic) must be removed. Which of the following should provide the most favorable conditions for effective exchange?
A) a smaller unicellular yeast
B) a larger unicellular yeast
C) a shorter filamentous hypha
D) a longer filamentous hypha

Some fungi can exist either as unicellular yeasts or as filamentous hyphae. Which of these forms would be most favorable in an environment where nutrients are limited?
A) a smaller unicellular yeast
B) a larger unicellular yeast
C) a shorter filamentous hypha
D) a longer filamentous hypha

For several decades now, amphibian species worldwide have been in decline. A significant proportion of the decline seems to be due to the spread of the chytrid fungus, Batrachochytrium dendrobatidis (Bd). Chytrid sporangia reside within the epidermal cells of infected animals, animals that consequently show areas of sloughed skin. They can also be lethargic, which is expressed through failure to hide and failure to flee. The infection cycle typically takes four to five days, at the end of which zoospores are released from sporangia into the environment. In some amphibian species, mortality rates approach 100%; other species seem able to survive the infection.

74) Sexual reproduction has not been observed in Bd. If its morphology and genetics did not identify it as a chytridiomycete, then to which fungal group would Bd be assigned?
A) ascomycetes
B) zygomycetes
C) glomeromycetes
D) basidiomycetes
E) deuteromycetes

Rose-picker's disease is caused by the yeast, Sporothrix schenkii. The yeast grows on the exteriors of rose-bush thorns. If a human gets pricked by such a thorn, the yeasts can be introduced under the skin. The yeasts then assume a hyphal morphology and grow along the interiors of lymphatic vessels until they reach a lymph node. This often results in the accumulation of pus in the lymph node, which subsequently ulcerates through the skin surface and then drains.

83) Humans have immune systems in which lymph nodes are important, because many phagocytes and lymphocytes reside there. Given that a successful infection by S. schenkii damages lymph nodes themselves, which of the following is most probable?
A) The hyphae secrete antibiotics, which increases the ability of the infected human to tolerate the fungus.
B) Their conversion from yeast to hyphal morphology allows such fast growth that the body's defenses are at least temporarily overwhelmed.
C) Defensive cells of humans cannot detect foreign cells that are covered with cell walls composed of cellulose.
D) Given that most fungal pathogens attack plants, human defenses are simply not adapted to seek out and destroy fungi.
E) Given that most fungal pathogens of humans infect only the skin, human defenses are not adapted to seek out and destroy systemic fungal infections.

All fungi share which of the following characteristics?
A) symbiotic
B) heterotrophic
C) flagellated
D) pathogenic
E) act as decomposers

Which feature seen in chytrids supports the hypothesis that they diverged earliest in fungal evolution?
A) the absence of chitin within the cell wall
B) coenocytic hyphae
C) flagellated spores
D) formation of resistant zygosporangia
E) parasitic lifestyle