I believe it is the first option
Answer:
The effect might be due to the gene expression.
Explanation:
The effect might be due to the variation in the gene expression in the organism. In this way, the variety of the genetic pool is likely to result in a diversity of the gene pool or genome. Because of the mutation and the environmental factors, there is likely to be a slight variation of the species. This results in a slight difference in the phenotypic expression.
The answer is A, reproduction.
The answer is A) prepares organisms for future changes in the environment
Hello!! The answer would be A - The SA node. It is known as the "pacemaker" because it initiates the heart's rhythmic contractions. I hope I helped!! Have a great day. :)