<span><span>a. </span>Reproducing</span>
f. obtaining
energy
d.
maintaining structure
Why do these
three illustrate the great challenge for every species.
<span><span>
1. </span>Reproduction, is as vital for an entire race to survive. It prolongs
their generation onwards and offspring to the next centuries to pass by.</span>
<span><span>
2. </span>Obtaining energy. In both humans and animals, even plants is a
challenge because these creatures need to work in order to obtain these need
resource from food –preys.</span>
<span><span>
3. </span><span>Maintaining structure. For the living organisms to still exist they
need to keep themselves intact. Combating diseases and having nutrition. This is
a by-product of having energy. </span></span>
At the bottom is the common phospholipid ,phosphatidylcholine.lipids are a group of naturally occurring molecules the include fats ,waxes ,sterols ,fat-soluble vitamins.
Answer:
From The School of Biomedical Sciences Wiki. Complementary base pairing is the phenomenon where in DNA guanine always hydrogen bonds to cytosine and adenine always binds to thymine. The bond between guanine and cytosine shares three hydrogen bonds compared to the A-T bond which always shares two hydrogen bonds.
