Question

read each example and identify it with one of the mechanisms that influence gene pools. 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. (options: mutation, gene flow, genetic drift, natural selection)

Explanation:

1. For "A zebra migrates to join a different herd of zebras": Gene flow is the transfer of genetic material from one population to another. Migration of an individual (zebra) between populations (herds) leads to gene flow as it introduces its genes to the new herd.
2. For "Competition for sunlight leads to taller trees": Natural selection occurs when organisms with traits (taller height in trees for sunlight) that enhance survival/reproduction are more likely to pass on their genes. Competition for resources (sunlight) drives natural selection for taller trees.
3. For "The DNA of a snake changes to make its venom stronger": Mutation is a change in DNA sequence. A change in the snake's DNA (to make venom stronger) is a mutation, as it's a heritable change in genetic material.
4. For "A grassfire randomly sweeps through a population of buffalo and kills most of them": Genetic drift is a random change in allele frequencies due to chance events. A grassfire (random event) killing most buffalo is a bottleneck effect, a type of genetic drift, as it randomly reduces the population and changes allele frequencies.

Answer:

1. A zebra migrates to join a different herd of zebras: gene flow
2. Competition for sunlight leads to taller trees: natural selection
3. The DNA of a snake changes to make its venom stronger: mutation
4. A grassfire randomly sweeps through a population of buffalo and kills most of them: genetic drift