It prevents harmful substances from entering a cell. I uses carrier proteins to do so.
<span> Both are similar in size, mass, density,
and volume. However, during the last few years scientists have found
that the kinship ends here. Venus is very different from Earth. It has
no oceans and is surrounded by a heavy atmosphere composed mainly of
carbon dioxide with virtually no water vapor. Its clouds are
composed of sulfuric acid droplets. At the surface, the atmospheric
pressure is 92 times that of the Earth's at sea-level.</span><span>
</span>
its C!!! i have to type random stuff so i can submit the answer but your welcome
<span>as you need to produce different phenotypes from the same genotype you need to regulate gene expression (turn some on, others off).</span>
compound consisting of a nucleoside linked to a phosphate group. Nucleotides form the basic structural unit of nucleic acids such as DNA.
