Question

read each example and identify it with one of the mechanisms that influence gene pools.
gene flow a zebra migrates to join a different herd of zebras.
competition for sunlight leads to taller trees.
mutation the dna of a snake changes to make its venom stronger.
gene flow a grassfire randomly sweeps through a population of buffalo and kills most of the
genetic drift
natural selection

Explanation:

For "Competition for sunlight leads to taller trees":

Natural selection is the mechanism where organisms with traits (like taller height for better sunlight access) that enhance survival/reproduction are more likely to pass on their genes. Here, trees competing for sunlight favor taller trees, so this is natural selection.

Mutation is a change in an organism's DNA. The snake's DNA changing to alter venom strength is a mutation event.

Genetic drift occurs when random events (like a grassfire) reduce population size, causing random changes in allele frequencies. The fire randomly killing buffalo is a bottleneck effect (type of genetic drift).

Answer:

natural selection

For "The DNA of a snake changes to make its venom stronger":