<span>While alien genomes may be constructed by completely different molecules (for example, silicon based life forms are a possibility rather than carbon) it is logical to assume that all life forms would have some sort of protective mechanism to prevent the degradation of DNA during replication. Essentially, to prevent mutations and rapid aging, DNA, alien or otherwise, would have some types of telomeres. They might either be long chains of repeated or irrelevant code or molecules that would not be easily corrupted.</span>
B. Steroid hormone
This is because most hormones are steroids, that send long distance signaling throughout your body.
Cell division starts with one parent cell and finishes with two cells. Each daughter cell has the same DNA as the parent cell
The most likely explanation for the variation is the offspring were produced from different combination of genes. A single pair of gold fish mentioned in the question means a male and a female gold fish. The two of them mated and contributed different genes to the fertilized fish eggs, this results in production of various body shape and colouration which is known as variation.
