Anything prokaryotic doesn't contain a nucleus
Its stabilising. Since the selection pressure is against the extremes which are the normal blood and the sickle cell anaemia.
Answer:
They also have a specialized non-lignified tissue (the phloem) to conduct products of photosynthesis. Vascular plants include the clubmosses, horsetails, ferns, gymnosperms (including conifers) and angiosperms (flowering plants).
AMINO ACIDS is the subunit of a protein molecule