The Following Questions Refer to Figure 27.1

question 23

Multiple Choice

The following questions refer to Figure 27.1.
In this eight-year experiment, 12 populations of E. coli, each begun from a single cell, were grown in low-glucose conditions for 20,000 generations. Each culture was introduced to fresh growth medium every 24 hours. Occasionally, samples were removed from the populations, and their fitness in low-glucose conditions was tested against that of members sampled from the ancestral (common ancestor) E. coli population.

Figure 27.1
-If new genetic variation in the experimental populations arose solely by spontaneous mutations, then the most effective process for subsequently increasing the prevalence of the beneficial mutations in the population over the course of generations is

• A) transduction.
• B) binary fission.
• C) conjugation.
• D) transformation.
• E) meiosis.

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Definitions:

"Minus" Lenses

Eyeglass lenses designed to correct myopia (nearsightedness) by diverging light rays before they reach the eye.

Conjunctiva

A thin, transparent membrane that covers the white part of the eyeball and the inner surfaces of the eyelids.

Choroid

A layer of the eye between the retina and the sclera, rich in blood vessels, that provides oxygen and nutrients to the outer parts of the retina.

Sclera

The white outer layer of the eyeball, providing protection and giving the eye its shape.