Microbiology MCQ

A dog is following the scent of a jackrabbit. Which of the following accurately describes how the dog’s brain integrates information for smell?

A) Chemoreceptors in the brain send impulses for smell in the nasal cavity.
• B) Chemoreceptor cells in the nasal cavity sends impulses to the appropriate area of the brain.
• C) Chemoreceptors on epithelial cells of the tongue send hormones to the appropriate area of the brain.
• D) Receptors originating in the nose send action potentials to the motor regions of the brain.

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Initially, which of the following isolating mechanisms is likely to have been the most important in preventing gene flow between the two populations of Rhagoletis?

A) Temporal isolation due to differences in mating time.
• B) Behavioral isolation due to differences in mating behaviors.
• C) Mechanical isolation due to differences in reproductive structures.
• D) Ecological isolation due to different host plants.

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Thrips are insects that feed on rose pollen. Scientists noted that the thrips population increased in the spring and decreased dramatically during the summer. The researchers hypothesized that food abundance was the limiting factor for the population. Which of the following types of data would be most useful for the scientists to collect at regular intervals on a designated test plot of rose plants?

A) Amount of sunlight (hours/day)
• B) Mean temperature (°C)
• C) Density of rose pollen produced (g/m²)
• D) Amount of pollen produced by each flower (g/flower)

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What is the main way in which the cells of the leaves of the small evergreen trees differ from the cells of the leaves of the large trees?

A) The cells of the leaves of the small evergreen trees have larger vacuoles.
• B) The cells of the leaves of the small evergreen trees have thicker cell walls.
• C) The cells of the leaves of the small evergreen trees have a greater number of chloroplasts.
• D) The cells of the leaves of the small evergreen trees have more mitochondria.

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If ATP breakdown (hydrolysis) is inhibited, which of the following types of movement across cell membranes is also inhibited?

A) Movement of oxygen into a cell
• B) Movement of water through aquaporins
• C) Passage of a solute against its concentration gradient
• D) Facilitated diffusion of a permeable substance

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Which of the following statements provides the best explanation for the main trend shown in the graph above?

A) The pigment concentration in leaves is not affected by light exposure.
• B) Leaf growth is positively correlated with pigment concentration.
• C) Pigment concentration is inversely correlated with light exposure.
• D) Leaf growth increases linearly with increased pigment concentration.

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Undersea landslides can disrupt marine habitats by burying organisms that live on the ocean floor. The graph above shows the size of a population of a certain organism that lives on the ocean floor. The population was affected by a recent landslide at the time indicated on the graph. Which of the following best predicts how the population will be affected by the landslide?

A) The surviving organisms will evolve into a new species.
• B) The reduced population will likely have allelic frequencies that are different from the initial population.
• C) The population will adapt to deeper waters to avoid future landslides.
• D) The reduced population will have a greater number of different genes than the initial population.

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The scientists can best determine whether the new trait evolved independently in each population by determining which of the following?

A) The relative fitness of each population in the presence of the new trait.
• B) The genetic sequences of the populations in the regions associated with the new trait.
• C) The extent of phenotypic variation of the new trait within each population.
• D) The environmental conditions experienced by each population over time.

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Which of the following questions is most relevant to understanding the Calvin cycle?

A) How does chlorophyll capture light?
• B) How is ATP used in the formation of 3-carbon carbohydrates?
• C) How is NADP+ reduced to NADPH?
• D) How is ATP produced in chemiosmosis?

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Based on the figure, which of the following conclusions is best supported by the data presented?

A) The soil conditions in the moist region are too extreme for most plant growth.
• B) There is a linear relationship between the number of plant species and the soil condition in the dry region.
• C) There is a positive correlation between plant species diversity and soil condition in the moist region.
• D) Soil conditions are a better predictor of plant species diversity in the dry region than in the moist region.

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