A, because it the constant variable
No, because the immune system is already battling with the virus or disease
39%. Adenine would have the same percentage as Thymine, meaning it would he 32% A and T and then subtract that from 100 giving you 72 divide that by 2 and you get part Guanine and part Cytosine.
All cells have robosomes, DNA, cytoplasm and plasma membrane.
I hope this helps!