Red blood cells have cell membranes that allow water, oxygen, carbon dioxide and glucose to pass through. all other materials are blocked form entering. this makes the membrane

not sure if this what   you'r looking for would be percent composition

a- multicellular

b-eukaryotic

c-no cell wall

d-heterotrophic

e-autotrophic

c) 50% there are four chromosomes. after crossing over, 2 of the four have been changed. that means any gamete has a 2 in 4 chance or 50% chance of receiving the mutated chromosome.

a bird that nests only in a particular tree species.