Answer: Pollen from a yellow daisy travels across a stream and pollinates an orange daisy.
Step-by-step explanation:
The gene flow can be define as the transfer of the genetic variation typically from one population to the other. If the rate of flow of gene is high enough, the two population in which the gene flow has occurred will become equivalent in allele frequencies and therefore will become the single population.
Pollen from a yellow daisy travels across a stream and pollinates an orange daisy. is the correct option, this is because of the fact that through pollen which is the male gamete the genetic variations are passing from one population to another population of the same species of daisy. Thus the allelic frequencies will become the equivalent in the two populations of the same species. Thus this will result in the formation of the single population.