Researchers found that a certain species of sea slug, elysia chlorotica, has in its genome a gene for repairing and maintaining chloroplasts. the gene is identical to one found in the algae from which the slugs steal chloroplasts for performing photosynthesis during periods of dietary shortfall. how did the slugs get the gene?

Through horizontal gene transfer.

Explanation:

Horizontal gene transfer, also known as the process of exchanging genetic material among two nearby bacteria, is a different means of resistance acquisition. This kind of gene transfer can take place through three principal mechanisms that are transformation, conjugation, or transduction. It is also a significant evolutive factor of a lot of organisms.

is there a year set? the question is incomplete

answer; participant observation method;