D. Polarity and size.
<span>The size, polarity, and charge of a substance will determine whether or not the substance can cross the cell membrane by diffusion. The cholesterol was an example of a lipid, and is highly soluble in the nonpolar environment of the lipid bilayer. You saw, in the animation above, the cholesterol freely passing into the hydrophobic environment of the membrane. Cholesterol distributes freely in the membrane and then some fraction will dissolve in the aqueous environment of the cytoplasm. Water, on the other hand, while polar, is small enough to cross the membrane at a slow rate. Note that specialized transport proteins in certain cell membranes can provide a channel for the water, greatly increasing its rate of crossing the membrane. The lipid bilayer is much less permeable to the ion, because of its charge and larger size. As a general rule, charged molecules are much less permeable to the lipid bilayer.</span>
Answer:Short
Explanation:Also I feel so bad for you.
There are basically three types of evolution divergent, convergent and parallel evolution.
a) Divergent Evolution – As the name depicts the species in this form of evolution becomes divergent i.e they evolve to become different from each other. This form of evolution is responsible for the current diversity of organisms existing on planet earth. For example human and apes evolved from a common primate ancestor.
