Be quick i'll give you the most brainliest answer read each example and decide what the resulting effect on the gene pool of that population would be. a zebra migrates to join a different herd of zebras. competition for sunlight leads to taller trees. the dna of a snake changes to make its venom stronger. a grassfire randomly sweeps through a population of buffalo and kills most of the animals.

"A zebra migrates to join a different herd of zebras"
This will increase the gene pool in the different herd.

"Competition for sunlight leads to taller trees."
This will decrease diversity in the gene pool to taller trees only.

"The DNA of a snake changes to make its venom stronger"
The gene pool may not change by alot if it is one snake, however, it adds that alle to the gene pool.

"A grassfire randomly sweeps through a population of buffalo and kills most of the animals. "
Genetic Drift will occur in the Gene Pool, decrease its diversity dramatically.

The effect in the gene pool of the population would be:

The zebras when migrating and joining the different herds of zebras will cause an increase in the gene pool of the other herd. A Gene pool is a genetic diversity found amongst the population or species. Competition is defined as the rivalry among organisms for shelter, food, light, and water. The competition for sunlight leads to the taller tree, which will result in a decrease in the genetic diversity among the taller trees. The DNA of a snake changes to make the venom stronger, but the gene pool would not be changed due to alteration in the one snake. However, the introduction of the altered sequence or the allele will be present in the gene pool.The grassfire causes the killing of most of the animals and population buffalo, which will lead to genetic drift. The diversity among the gene pool will be decreased drastically and the population of various organisms will be eliminated.

To know more about the gene pool, refer to the following link:

link