Red blood cells are disc shaped. It is thought one factor that allows them to have this shape is because they do not have a nucleus. This tends to increase amount of space inside the cell for hemoglobin.
They have a flexible disc shape which helps increase the surface- to- area volume ratio which enables oxygen and carbon dioxide to diffuse across the red blood cell's plasma membrane more readily.
Their disc shape also enables them to squeeze through tiny capillaries that are half their size .
Answer - Theory
Reasoning - Your best bet and term to describe the evolution by natural selection is theory as to still scientific theory/research is still ongoing and changes can be made in a different direction.
Answer: You use a restatement of the speech's thesis; a review of the main points discussed within the speech; and a concluding device that helps create a lasting image in audiences' minds.
Explanation:
The answer is D. The offspring will have no genetic differences from their parents.