Gene flow is partially responsible for .. a) genetic sameness b) genetic variation

The gene flow is responsible for the (b) genetic variation.

The gene flow is a concept of genetics where the genes or alleles move between the individuals in an interbreeding population of species. When a member belonging to a particular gene pool (collection of unique genes) mates with another member of a different gene pool, the gene frequencies change for the various genes in the progeny. This helps in maintaining the genetic variation in the population of the interbreeding species.

when the displaced particles are perpendicular to the direction the wave travels, is called a transverse wave, whereas in longitudinal wave the displace practices are parallel to the direction of the wave.

in the given image:

first image shows - longitudinal wave

second image shows - transverse wave

third image shows - longitudinal wave

fourth image shows - longitudinal wave