The answer for 21 I think is false
Answer:
Usually the Y chromosome. It is recessive because if one Y chromosone is mutated with red-green colorblindness and the X is not, the child will have colorblindness. But, if one X chromosome has the mutation and the other X does not, they will cancel out, meaning the child will not have colorblindness.
<span>The correct answer is A, B and D. Biogeochemical cycles are central to the ecology of earth system. They make the essentail elements accessible and available for the organisms, and maintain their levels, so that the ecology is ot disrupted. The elements move through abiotic and biotic factors, in these cycles, and a state of equilibrium is maintained n the ecosystem. The carbon dioxide levels are responsible fr the temperature of the earth. If Carbon cycles would not have existed, then there would have been a disruption in maintaining the global temperature. Biogeochemical cycles basically continuously recycles the essential materials, for sustaining the life-forms.</span>
It is not common but yes an ab parent can have an O child
The answer is prime mover