In mitosis, each chromosome is made up of that carry the same alleles.
A. sister chromatids
B. homologous pairs
C. homologues
D. sister pairs

Option A) sister chromatids

In mitosis, each chromosome is made up of sister chromatids that carry the same alleles.

Explanation:

During the fourth phase of mitosis (Anaphase) the sister chromatids part company and migrate to the opposite poles, each with the same alleles since no crossing over occurred.

Thus, mitosis results in two daughter cells that have the same chromosome make-up as the original parent cell.

good thing- during decomposition the organic molecules in organic matter are broken down into simpler organic molecules that require further decomposition or into mineralised nutrients

bad thing- it can be harmful in crop productivity

the reason the two sea urchins don't compete with each other for food, resources, etc. is because the urchins have adapted to the environment but they have also adapted to each other. this is most likely because the genes of the sea urchins.