The answer is D<span>. Cell walls are made of cellulose. Cell membranes are made of proteins and phospholipids
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<span>Spermatozoa are the mature male gametes in many sexually reproducing organisms. Thus, spermatogenesis is the male version of gametogenesis, of which the female equivalent is oogenesis. In mammals it occurs in the seminiferous tubules of the male testes in a stepwise fashion.</span>
<span>I think it would be A.) Anemia, reducing the delivery of oxygen to the brain </span>
