The Quaternary period represents the last two million years of geologic time.
Well, I don't fully understand your question. I think I know what you're getting at though.
In a system of sexual reproduction, you have genes coming from both an egg and the sperm. Therefore, it'll only contain half the total amount of chromosomes (46 in humans). A sperm will have 23, and the egg will have the other 23. Is that what you meant why the chromosomes are cut out in pairs? If that wasn't your question, please elaborate and I'll return to answer it to the best of my capabilities.
The one for the cells is the
cells need to be able to get oxygen gas nutrients and get carbon dioxide out quickly.
i’m not sure for the other ones
So a change in an organism's DNA can cause changes in all aspects of its life.Mutations<span> are essential to </span>evolution<span>; they are the raw material of genetic variation. Without </span>mutation<span>, </span>evolution<span> could not occur.</span>