D.
Selective breeding
In selective breeding, the desired genes from one organism are combined with genes of another organism, resulting in a new combination of genes.
<span>The selective breeding is quite voluntary and is not necessarily natural or congenital. It is the act of how people or individuals can choose traits in the gene pool of their choice to produce their desired or goal organism in the process. This trait is influenced in the host of the specific sperm and egg cell which makes up the chromosomes. </span>
Well, depending on how long the migration is, many of the animals (mainly birds) could get sick and die, lowering the population. They could be shot by hunters, lowering the population. The children of the population could get left behind and lose their way, lowering the population. I'm not entirely sure how the population could grow other than them finding and staying with another group of their own kind. hope I was helpful! :)
D. It occurs before an organism can reproduce. Meiosis is the replication of sex cells required for sexual reproduction to occur.
Symbiosis can vary between mutualism, parasitism, and commensalism, tho these grade into each other, it is often difficult to tell which is involved in a given relationship.
