Copy of Unused Mecahinisms Questions (5/2/2026)

A population of Escherichia coli (E. coli) bacteria is exposed to a new antibiotic. Most of the bacteria are killed by the antibiotic, but a few survive. After examining the survivors, scientists discover that a random change in the DNA of one bacterium has enabled it to resist the effects of the antibiotic. This bacterium reproduces, and over several generations, more and more bacteria in the population show resistance to the antibiotic.

The ability for E. coli to resist antibiotics is due to. As a result of this change, geneticin the population.

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Consider the breeding of two types of corn: one that has high yield but is non-resistant to a certain pest, and another that is resistant to that pest but has a lower yield.

During the process of pollination (reproduction), the pollen from one corn plant fertilizes the ovule of another. The resulting hybrid plants will have both high yield and pest resistance.

The evolution mechanism that BEST supports creating a new hybrid plant is . As a result of this new plant the populations variation will.

A population of insects is exposed to a pesticide. Some insects survive because they inherit a combination of genes from their parents that allows them to detoxify the pesticide. Over several generations, more insects survive and reproduce, passing on this beneficial genetic mix. How might this change the makeup of the population over time?

The combination of genes is due to .

As a result the genetic variation of the insect population will

over time.

In the original population of flies, some have red eyes and some have white eyes. After 5 generations, some have red eyes, some have white eyes, and some have brown eyes.

This is an example of , and variation as a result.

A road is built through a field which separates a population of Texas tortises.

The separation/isolation and the diversity .

Practice

A land bridge is built over the same road to allow for the tortoise populations to mix again.

In constructing the land bridge, can continue.

As turtles from either side of the bridge mate,

.