If the e and f genes are expressed, the xi chromosome will be prevented from reaching 100% frequency if selection pressures cause which of the following to be true?

The options

A. XsXs flies have the lowest fitness of any genotype.

B. XsXs flies have the highest fitness of any genotype.

C. XiY flies and XsY flies have equal fitness.

D. XiXs flies and XsXs flies have equal fitness

The CORRECT ANSWER IS

a. XsXs flies have the highest fitness of any genotype.

Explanation:

From the text:

Xi will have a frequency of 100% as far as the Xi bearing genotype is not picked. Options C and D are wrong since not being picked is equal to same fitness level.

The amount of Xs in relation to Xi population will increase as long as XsXs genotype as the largest fitness and there is difference in fitness between the other genotypes

currents is the correct answer.

i'm thinking (a) to keep sand in place; ////////////

explanation: a sand fence or sandbreak, like a snow fence, is used to force windblown, drifting sand to accumulate in a desired place. sand fences are employed to control erosion, sand dune stabilization, keep sand off roadways, and to recruit new material in desert areas.