Biology Exam 1

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) golden algae C) dinoflagellates D) green algae E) brown algae

A

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

A

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

A

In life cycles with an alternation of generations, multicellular haploid forms alternate with A) multicellular diploid forms. B) unicellular haploid forms. C) multicellular haploid forms. D) multicellular polyploid forms. E) unicellular diploid forms.

A

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) phylogenies. B) the scientific discipline known as taxonomy. C) classifying organisms using the morphospecies concept. D) a hierarchical classification scheme. E) nested, ever-more inclusive categories of organisms.

A

Many types of foraminiferans form a symbiotic relationship with _____. A) algae B) bacteria C) seaweed D) fungi E) amoebas

A

Select the correct statement about photosynthesis by primary producers. A) Photosynthetic protists and prokaryotes carry out the majority of the photosynthesis in aquatic communities. B) Cyanobacteria carry out more of the world's photosynthesis than protists do. C) Land plants carry out over 80% of the world's photosynthesis.

A

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

A

True or false? Data showing that the Bacteria were the first lineage to diverge from the common ancestor of all living organisms suggest that the Archaea and Eukarya are more closely related to each other than they are to the Bacteria. A) True B) False

A

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

A

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

B

Bioremediation is _____. A) the use of prokaryotes in producing transgenic organisms B) the use of organisms to remove pollutants from the environment C) the use of biological processes to remedy diseases D) the modification of prokaryotes for industrial purposes E) the use of prokaryotes in producing pharmaceutical products

B

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 also A) lack a cell wall. B) lack antibiotic-resistant genes. C) lack water in its cytoplasm. D) be unable to survive in its normal environment. E) lack a chromosome.

B

In general, what is the primary ecological role of prokaryotes? A) serving as primary producers in terrestrial environments B) breaking down organic matter C) metabolizing materials in extreme environments D) parasitizing eukaryotes, thus causing diseases E) adding methane to the atmosphere

B

Match the numbered terms to the description that follows. Choose all appropriate terms. 1. autotroph 2. heterotroph 3. phototroph 4. chemotroph an organism that obtains both carbon and energy by ingesting prey A) 4 only B) 2 and 4 C) 1 and 3 D) 1, 3, and 4 E) 1 only

B

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) translation B) horizontal gene transfer C) endocytosis D) conjugation E) plasmolysis

B

Plastids that are surrounded by more than two membranes are evidence of A) fusion of plastids. B) secondary endosymbiosis. C) budding of the plastids from the nuclear envelope. D) origin of the plastids from archaea. E) evolution from mitochondria.

B

Select the valid comparison between eukaryotes and prokaryotes. A) The total biomass of eukaryotes is approximately ten times the total biomass of prokaryotes. B) Prokaryote cells have simpler internal structure and genomic organization than eukaryotic cells. C) Eukaryotes are far more metabolically diverse than prokaryotes.

B

Similar to most amoebozoans, the forams and the radiolarians also have pseudopods, as do some of the white blood cells of animals (monocytes). If one were to erect a taxon that included all organisms that have cells with pseudopods, what would be true of such a taxon? A) It would include all eukaryotes. B) It would be polyphyletic. C) It would be monophyletic. D) It would be paraphyletic.

B

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

B

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

B

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

B

Which of the following statements about phylogenetic trees is true? A) A paraphyletic group consists of an ancestral population and all of its descendants. B) A paraphyletic group consists of a common ancestor and some of its descendants. C) A monophyletic group consists of a common ancestor and some of its descendants. D) A paraphyletic group has not experienced lateral gene transfer.

B

Which of the following taxonomic categories contains all the others listed here? A) species B) class C) order D) genus E) family

B

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

B

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

B

Which statement about endotoxins is true? A) The source of endotoxins is endospores. B) Endotoxins are released only when bacteria die and their cell walls break down. C) An example of a prokaryote that produces endotoxins is Clostridium botulinum. D) Endotoxins are components of the cell wall of gram-positive bacteria. E) Endotoxins are proteins secreted by prokaryotes.

B

You are designing an artificial drug-delivery "cell" that can penetrate animal cells. Which of these protist structures should provide the most likely avenue for research along these lines? A) excavated feeding grooves B) apical complex C) nucleomorphs D) pseudopods E) mitosomes

B

Archaeplastids, which include red and green algae and land plants, are thought to have descended from a heterotrophic protist that engulfed a(n) _____. A) slime mold B) alpha proteobacterium C) cyanobacterium D) apicomplexan E) archaean extremophile

C

Foods can be preserved in many ways by slowing or preventing bacterial growth. Which of these methods should be least effective at inhibiting bacterial growth? A) Canning in heavy sugar syrup: creates osmotic conditions that remove water from most bacterial cells. B) Refrigeration: slows bacterial metabolism and growth. C) Closing previously opened containers: prevents more bacteria from entering, and excludes O2. D) Pickling: creates a pH at which most bacterial enzymes cannot function. E) Irradiation: kills bacteria by mutating their DNA to such an extent that their DNA-repair enzymes are overwhelmed.

C

Genes for the resistance of antibiotics are usually located _____. A) in mitochondria B) on the outside of the cell wall C) on plasmids D) in eukaryotic cells E) on the main chromosome

C

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 polyphyletic. B) It will be a true clade. C) It will be paraphyletic. D) It will be monophyletic. E) It will more accurately depict evolutionary relationships than does the current taxonomy.

C

Match the numbered terms to the description that follows. Choose all appropriate terms. 1. autotroph 2. heterotroph 3. phototroph 4. chemotroph an organism that obtains energy from light A) 2 and 4 B) 1 only C) 3 only D) 1 and 3 E) 1, 3, and 4

C

Reinforced, threadlike pseudopods that can perform phagocytosis are generally characteristic of which group? A) gymnamoebas B) oomycetes C) radiolarians and forams D) entamoebas E) amoeboid stage of cellular slime molds

C

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) scientists have no evidence to indicate whether or not land plants evolved from any kind of alga. B) land plants evolved directly from the green algae that perform alternation of generations. C) plants evolved alternation of generations independently of green algae. D) alternation of generations cannot be beneficial to charophytes. E) charophytes are not related to either green algae or land plants.

C

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

C

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

C

Which molecule did Carl Woese study to produce his tree of life? A) Ribosome B) Messenger RNA C) Ribosomal RNA D) DNA

C

Which process occurred frequently in the early history of the three domains on Earth, and makes determining phylogenetic relationships of that time difficult? A) meiosis B) mitosis C) horizontal gene transfer D) binary fission E) alternative RNA splicing

C

Which statement about the genomes of prokaryotes is correct? A) The prokaryotic chromosome is not contained within a nucleus but, rather, is found at the nucleolus. B) Prokaryotic cells have multiple chromosomes, "packed" with a relatively large amount of protein. C) Prokaryotic genomes are composed of circular DNA. D) Prokaryotic genomes are diploid throughout most of the cell cycle. E) Prokaryotic chromosomes are sometimes called plasmids.

C

Why is the filamentous morphology of the water molds considered a case of convergent evolution with fungi? A) Water molds evolved from filamentous fungi. 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 the first and second responses above are correct.

C

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

D

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

D

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

D

Bacteria that live around deep-sea, hot-water vents obtain energy by oxidizing inorganic hydrogen sulfide belched out by the vents. They use this energy to build organic molecules from carbon obtained from the carbon dioxide in seawater. These bacteria are _____. A) photoheterotrophs B) photoautotrophs C) chemoheterotrophs D) chemoautotrophs

D

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 nitrogen. B) unable to synthesize peptidoglycan. C) unable to fix carbon dioxide. D) deficient in certain vitamins and nutrients. E) antibiotic resistant.

D

Jams, jellies, preserves, honey, and other foodstuffs with high sugar content hardly ever become contaminated by bacteria, even when the food containers are left open at room temperature. This is because bacteria that encounter such an environment A) experience lysis. B) are obligate anaerobes. C) are unable to swim through these thick and viscous materials. D) undergo death as a result of water loss from the cell. E) are unable to metabolize the glucose or fructose, and thus starve to death.

D

Match the numbered terms to the description that follows. Choose all appropriate terms. 1. autotroph 2. heterotroph 3. phototroph 4. chemotroph a prokaryote that obtains both energy and carbon as it decomposes dead organisms A) 1 and 3 B) 1, 3, and 4 C) 1 only D) 2 and 4 E) 4 only

D

Plastids that are surrounded by more than two membranes are evidence of A) fusion of plastids. B) origin of the plastids from archaea. C) budding of the plastids from the nuclear envelope. D) secondary endosymbiosis. E) evolution from mitochondria.

D

The closest algal relatives of land plants are _____. A) chrysophytes B) psilophytes C) bacillariophytes D) charophytes E) rhodophytes

D

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 have cell walls only for protection from herbivores. B) Some have cell walls only to control osmotic balance. C) Some closely resemble animals, which lack cell walls. D) Their cell walls are composed of very different biochemicals. E) Some have cell walls only for support.

D

What characteristics were used to classify organisms before Woese's tree of life analysis? A) Number of cells in the organism B) Composition of the cell wall C) Differences in ribosomal RNA sequences D) Presence of a membrane-bound nucleus

D

What is lateral gene transfer? A) Inheritance of a gene through mitosis B) Inheritance of a gene through meiosis C) Inheritance of a gene from a parent D) Physical transfer of a gene from a species in one lineage to a species in another lineage.

D

Which group was not described in Woese's tree of life analysis? A) Archaea B) Bacteria C) Eukarya D) Prokarya

D

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

D

Which of the following is true of secondary endosymbiosis? A) It is indicated by the presence of a double membrane surrounding the endymbiont. B) An organism containing one endosymbiont engulfs another organism, and that organism becomes an endosymbiont. C) It is indicated by the presence of a nucleomorph. D) An organism containing an endosymbiont is engulfed by another organism and becomes an endosymbiont. E) It is indicated by the presence of a mixotroph.

D

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

D

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

D

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

D

According to our current knowledge of plant evolution, which group of organisms should feature mitosis most similar to that of land plants? A) multicellular green algae B) unicellular green algae C) cyanobacteria D) red algae E) charophytes

E

An ecological relationship between organisms of different species that are in direct contact can best be described as _____. A) taxis B) mutualistic C) parasitic D) commensal E) symbiotic

E

Biologists suspect that endosymbiosis gave rise to mitochon-dria before plastids partly because A) mitochondrial proteins are synthesized on cytosolic ribo-somes, whereas plastids utilize their own ribosomes. B) the products of photosynthesis could not be metabolized without mitochondrial enzymes. C) mitochondrial DNA is less similar to prokaryotic DNA than is plastid DNA. D) without mitochondrial production, photosynthesis could not occur. E) all eukaryotes have mitochondria (or their remnants), whereas many eukaryotes do not have plastids.

E

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

E

How does the large amount of genetic variation observed in prokaryotes arise? A) The mutation rate in prokaryotes is much higher than in eukaryotes. B) They have extremely short generation times and large populations. C) They can exchange DNA with many types of prokaryotes by way of horizontal gene transfer. D) They have a relatively small genome. E) The second and third answers are correct.

E

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

E

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) possession of shared primitive characters. C) sexual selection. D) inheritance of shared derived characters. E) possession of analogous structures.

E

Which of the following are actual mutualistic partnerships that involve a protist and a host organism? A) dinoflagellates-reef-building coral animals B) algae-certain foraminiferans C) cellulose-digesting gut protists-wood-eating termites D) Trichomonas-humans E) all except that involving humans

E

Which of the following are two groups that are adapted to anaerobic conditions and contain modified mitochondria that lack DNA? A) dinoflagellates and diatoms B) chlorophytes and radiolarians C) apicomplexans and forams D) gymnamoebas and slime molds E) diplomonads and parabasalids

E

Why has the kingdom Protista been abandoned? (Overview) A) Some protists are multicellular. B) The kingdom Protista is polyphyletic. C) Some protists are more closely related to plants, animals, or fungi than they are to other protists. D) Some protists are as small as prokaryotes. E) The second and third answers are correct.

E