CAMPBELL 27 TEST BANK

PDF Download

CAMPBELL 27 TEST BANK

Actual Qs and Ans - Expert-Verified Explanation -Guaranteed passing score -69 Questions and Answers

-Format: Multiple-choice / Flashcard

Question 1: 65) Leaf-cutter ants harvest plant leaves and bring them back to their nests.There, in the warm, moist environments of their underground nests, they grow fungi (Leucoagaricus) that they then eat. These ants also host bacteria on their exoskeleton.Another fungus, Escovopsis, kills Leucoagaricus when the ants are removed from the nest. Knowing that the bacteria on the ants are in the same phylogenetic group of other bacteria that produce antibiotics, which of the following research hypotheses is most likely correct?

Answer:

• The bacteria on the exoskeleton provide nutrition to the ants.

Question 2: 1) 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

• bacteriophorus on its way to the prey's cytoplasm?

Answer:

• capsule, lipopolysaccharide membrane, peptidoglycan, phospholipid membrane

Question 3: 63) 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 ________.

Answer:

• deficient in certain vitamins and nutrients

Question 4: 47) Which of the following traits do archaeans and bacteria share?

Answer:

• lack of a nuclear envelope and presence of circular chromosome

Question 5: 35) Biologists sometimes divide living organisms into two groups: autotrophs and heterotrophs. These two groups differ in ________.

Answer:

• their sources of carbon

Question 6: 55) Recently, a microbe that is able to digest cellulose was discovered in a hot spring with an average temperature of 95°C. Predict the group to which this microbe most likely belongs.

Answer:

• Archaea

Question 7: 24) The following table depicts characteristics of five prokaryotic species (A-E). Use the information in the table to answer the question.Which species might include cells that are Hfr cells?

Answer:

• species D

Question 8: 69) Compared to eukaryotes, prokaryotes are ________.

Answer:

• simpler morphologically, but not more evolutionarily primitive

Question 9: 19) Use the following information and graph to answer the question.

The figure below 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

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

Answer:

• It has a different sequence of base pairs.

Question 10: 46) Which statement about the domain Archaea is accurate?

Answer:

• Genetic prospecting has recently revealed the existence of many previously unknown archaean

species.Question 11: 22) 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. The cell also lacks F factors and F plasmids. Which of the following statements about the bacteria is most probably accurate?.

Answer:

• The bacterium cannot donate DNA through conjugation with another cell.

Question 12: 49) Assuming that each of these possesses a cell wall, which prokaryotes should be expected to be most strongly resistant to plasmolysis in hypertonic environments?

Answer:

• extreme halophiles

Question 13: 52) The following table depicts characteristics of five prokaryotic species (A-E).Use the information in the table to answer the question.Which species is most likely to be found in sewage treatment plants and in the guts of cattle?

Answer:

• species B

Question 14: 3) Use the information in the following paragraph to answer the question.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.This bacterium's ability to survive in a human who is taking penicillin pills may be due to the presence of ________.

Answer:

• gram-negative cell wall

Question 15: 38) Use the following information to answer the question.

Nitrogenase, the enzyme that catalyzes nitrogen fixation, is inhibited whenever free oxygen (O2) reaches a critical concentration. Consequently, nitrogen fixation cannot occur in cells wherein photosynthesis produces free O2. Consider the colonial aquatic cyanobacterium, Anabaena, whose heterocysts are described as having "...a thickened cell wall that restricts entry of O2 produced by neighboring cells. Intercellular connections allow heterocysts to transport fixed nitrogen to neighboring cells in exchange for carbohydrates." Given that the enzymes that catalyze nitrogen fixation are inhibited by oxygen, what mechanism might nitrogen-fixing prokaryotes use to protect these enzymes from oxygen?

Answer:

• live only in anaerobic environments

Question 16: 12) 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?

Answer:

• plasmids, nucleoid, and endospore

Question 17: 14) Chloramphenicol is an antibiotic that targets prokaryotic (70S) ribosomes, but not eukaryotic (80S) ribosomes. Which of these questions stems from this observation, plus an understanding of eukaryotic origins?

Answer:

• If chloramphenicol inhibits prokaryotic ribosomes, should it not also inhibit mitochondrial ribosomes?

Question 18: 60) 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?

Answer:

• mutualist, pathogen, nutrient recycler

Question 19: 9) The following table depicts characteristics of five prokaryotic species (A-E). Use the information in the table to answer the following question.How many of these species probably have a cell wall that consists partly of an outer membrane of lipopolysaccharide?

Answer:

• three species