Test Prep for AP® Courses

51.
Which of the following pieces of evidence is the BEST support for the alternative scenario of early life formation, in which organic compounds on early Earth formed near submerged volcanoes?
  1. Some prokaryotes that live near deep-sea vents today use hydrogen as an energy source.
  2. Fossilized stromatolites that are 3.5 billion years old are found near deep-sea vents.
  3. Extremophiles that exist today live in a variety of extreme environments, including those that are high in salinity.
  4. The chemical composition of water around deep-sea vents is the same as it was on early Earth.
52.

When Miller and Urey repeated their experiment without the electrical discharge, no organic compounds were found. Hypothesize what might explain this result. Consider your answer in the context of the conditions of early Earth.

  1. The lack of organic compounds without the sparks indicates that organic components are formed from biotic components.
  2. The first trial of the experiment must have been done incorrectly.
  3. Abiotic molecules can only develop into organic molecules in the presence of oxygen, so oxygen should be added.
  4. Lightning, or some form of energy, is needed for the inorganic molecules in the atmosphere to interact with each other. This indicates that a similar energy source was present on early Earth, which stimulates the interaction and development.
53.
Laboratory experiments have demonstrated that the abiotic synthesis of organic molecules in condition similar to those of early Earth is possible. Which of the following provides additional support for the idea of abiotic synthesis of organic compounds?
  1. Analysis of the chemical composition of meteorites sometimes yields amino acids.
  2. A hydrothermal vent in the Sea of Cortés releases hydrogen sulfide and iron sulfide.
  3. Researchers have dripped solutions of amino acids onto hot surfaces to produce amino acid polymers.
  4. Some present-day prokaryotes live and reproduce in very extreme and unforgiving environments, such as the Arctic.
54.

Which of the following cell types does the diagram illustrate?

In this illustration, the prokaryotic cell is rod shaped. The circular chromosome is concentrated in a region called the nucleoid. The fluid inside the cell is called the cytoplasm. Ribosomes, depicted as small circles, float in the cytoplasm. The cytoplasm is encased by a plasma membrane, which in turn is encased by a cell wall. A capsule surrounds the cell wall. The bacterium depicted has a flagellum protruding from one narrow end. Pili are small protrusions that project from the capsule all over the ba
  1. plant cell
  2. animal cell
  3. bacterial cell
  4. fungal cell
55.

Which option best describes the function and presence of cell organelles among prokaryotes and eukaryotes?

  1. Ribosomes are the sites of protein synthesis found in prokaryotic and eukaryotic cells. The cell wall is a protective layer, present in most prokaryotic cells and in some eukaryotes. Chromosomal DNA, the genetic material of the cell, is present in a nucleoid region in prokaryotes while enclosed in a nucleus in eukaryotes.
  2. Ribosomes are the sites of protein synthesis found in prokaryotic and eukaryotic cells. The cell wall is a protective layer found in a few prokaryotic and eukaryotic cells. Chromosomal DNA is the genetic material of the cell that is present in a nucleoid region in prokaryotes while in eukaryotes, it is enclosed in a nucleus.
  3. Ribosomes are sites of ATP production found in both prokaryotic and eukaryotic cells. The cell wall is a protective layer, typically found in prokaryotic cells and in some eukaryotes. Chromosomal DNA is present in a nucleoid region while enclosed in a nucleus in eukaryotes. It is the genetic material of the cell.
  4. Ribosomes are the sites of protein synthesis found in prokaryotic and eukaryotic cells. The cell wall is a protective layer, typically found in prokaryotic cells and in some eukaryotes. Chromosomal DNA, the genetic material of the cell is present in a nucleus in prokaryotes, while it is enclosed in a nucleoid region in eukaryotes.
56.
A nonpathogenic bacterium acquires resistance to antibiotics. Which of the following scenarios describing how this strain could pose a health risk to people is false?
  1. Genes for antibiotic resistance are transferred from the nonpathogenic bacterium to a pathogenic bacterium via transduction.
  2. Genes for antibiotic resistance are transferred from the nonpathogenic bacterium to a pathogenic bacterium via transformation.
  3. Genes for antibiotic resistance are transferred from the nonpathogenic bacterium to a pathogenic bacterium via conjugation.
  4. Genes for antibiotic resistance are transferred from the nonpathogenic bacterium to a pathogenic bacterium via binary fission.
57.

In a rapidly changing environment, which prokaryotic population would you hypothesize likely to be more successful: one that included individuals capable of conjugation or one that did not?

  1. A population including individuals capable of conjugation would be more successful, because all of its members would form recombinant cells having new gene combinations advantageous in a new environment.
  2. A population including individuals capable of conjugation would be more successful, as some members could form recombinant cells having new gene combinations advantageous in a new environment.
  3. A population including individuals not capable of conjugation would be more successful, as the members undergoing conjugation would form new recombinant cells having gene combinations lethal in the new environment.
  4. A population including individuals not capable of conjugation would be more successful, because conjugation will result in an increase in genetic diversity of the prokaryotic population, which will be disadvantageous in a new population.
58.

Given your understanding of the experiment and of bacterial genetic recombination, explain why there are fewer colonies on plate IV than on plate III.

  1. All E. coli cells were not successfully transformed on plate IV.
  2. The nutrient agar medium inhibited the growth of some bacteria on plate IV.
  3. All E. coli cells were successfully transformed on plate IV.
  4. The bacteria in plate III were naturally resistant to ampicillin.
59.
Which of the labeled structures in the diagram allows you to positively identify the cell as a prokaryote?
This image shows a cut-away view of a representative bacterial cell. There are four lines each designated with a letter. Letter A points to strands of material in the innermost part of the cell. Letter B points to small dots in the innermost part of the cell. Letter C points to a middle layer of three layers that cover the cell. Letter D points to a clear substance in the innermost part of the cell.
  1. Structure A – circular DNA
  2. Structure B – ribosome
  3. Structure C – cell wall
  4. Structure D – cytoplasm
60.

What is another question you might pose to learn more about the structural features that allow for the capture, storage, and use of free energy by archaean methanogens?

  1. Do archaean methanogens differ from other Archaea structurally, and if so, in what way? Is one or more of these structural differences related to these methanogens’ ability to use H2 to oxidize CO2?
  2. Do archaean methanogens differ from other Bacteria structurally, and if so, in what way? Is one or more of these structural differences related to these methanogens’ ability to use CO2 to oxidize H2?
  3. Do archaean methanogens differ from other Archaea structurally, and if so, in what way? Is one or more of these structural differences related to these methanogens’ ability to use CO2 to oxidize H2?
  4. Do archaean methanogens differ from other Archaea structurally, and if so, in what way? Is one or more of these structural differences related to these methanogens’ ability to use H2O to oxidize H2?
61.
Which set of phrases related to nutritional and metabolic adaptations best fits the organisms described?
  1. chemoautotrophs, obligate anaerobes
  2. chemoautotrophs, faculative anaerobes
  3. chemoheterotrophs, faculative anaerobes
  4. chemoheterotrophs, obligate anaerobes
62.
In an experiment, researchers grew plant seedlings in soils to which one of two strains of bacteria were added. A control group had no bacteria added to the soil. The seedlings’ uptake of the nutrient potassium increased dramatically in the soil with Strain 1 and decreased dramatically in the soil with Strain 2. What specific and broad inferences about the relationship between the bacteria, the seedlings, and available nutrients can you make?
  1. The Strain 2 bacteria increased the availability of potassium in the soil and this nutrient was needed and used by the seedlings in the soil. The Strain 1 bacteria decreased the availability of potassium in the soil.
  2. The soil with Strain 1 bacteria must have had more potassium in comparison to soil with Strain 2 bacteria. The seedlings took up more potassium in Soil 1 than in 2 due to this.
  3. The Strain 1 bacteria increased the availability of potassium in the soil and this nutrient was needed and used by the seedlings in the soil. The Strain 2 bacteria decreased the availability of potassium in the soil.
  4. The Strain 1 bacteria decreased the availability of potassium in the soil and this nutrient was needed and used by the seedlings in the soil. The Strain 2 bacteria increased the availability of potassium in the soil.


    Use the following information for Questions 63–65:
    In a hypothetical research situation, scientists discover bacterial endospores in silt at the bottom of a marsh that has been contaminated with a pollutant for 25 years. The silt of the marsh was deposited in annual layers. The age of the endospores can be estimated, therefore, by identifying the layer of silt in which the endospores are found. In flask A, researchers place 20-year-old endospores along with growth medium and the pollutant. In flask B, researchers place 100-year-old endospores along with growth medium and the pollutant.
63.
Which statement describes the results you would expect to see in the growth of the flasks?
  1. The growth in flask A will exceed that of flask B.
  2. The growth in flask B will exceed that of flask A.
  3. The growth each flask will be about equal.
  4. There will be little to no growth in each flask.
64.
Explain why you would expect to see more growth in one particular flask than in the other.
  1. Because endospores formed 20 years ago would be more dormant compared to endospores formed 100 years ago, before the marsh was polluted.
  2. Because endospores formed 20 years ago would be less adapted to polluted conditions compared to endospores formed 100 years ago, before the marsh was polluted.
  3. Because endospores formed 20 years ago would be more adapted to polluted conditions compared to endospores formed 100 years ago, before the marsh was polluted.
  4. Because endospores formed 20 years ago would be less dormant compared to endospores formed 100 years ago, before the marsh was polluted.
65.
Suppose the researchers observe the flasks for a while, continuing to replenish growth medium and pollutant as necessary. Which statement describes the results you would expect to see in the growth of the flasks after some time?
  1. The growth in flask A will continue to exceed that of flask B.
  2. The growth in flask B will exceed continue to exceed that of flask A.
  3. Eventually, the difference in the growth in each flask will lessen.
  4. Eventually, will be little to no growth in each flask.
66.

How does resistance spread in bacteria?

  1. by undergoing genetic recombination through conjugation, transduction, and transformation
  2. by undergoing reproduction through binary fission
  3. by undergoing genetic recombination through conjugation and transformation only
  4. Reproduction among bacteria through any mechanism results in the spread of antibiotic resistance genes.
67.

Human intestines are home to hundreds of species of bacteria. One of these, Bacteriodes thetaiotaomicron, has the capability of digesting complex plant materials that human enzymes cannot digest. Its presence in the human guts makes a significant contribution to human metabolic processes.Which term best describes the relationship between humans and B. thetaiotaomicron?

  1. commensalistic
  2. mutualistic
  3. parasitic
  4. pathogenic
68.

More than 100 bacterial species live on the surface of the human body. Bacteria cover portions of human skin in concentrations of up to 8 million cells per square centimeter. In particular, human sebaceous glands support the growth of the bacterium Propionibacterium acnes, which uses oil from the glands for food. Two strains of P. acnes are associated with the development of acne on human skin, but other strains are associated with healthy skin. Which statement best describes the relationship between humans and P. acnes?

  1. In some cases it is commensal and in others it is parasitic.
  2. In some cases it is mutualistic and in others it is commensalistic.
  3. It is almost always parasitic.
  4. It is almost always mutualistic.