***see attached pic***
Some helpful tips:
The nucleus is always going to be the big, spherical shape.
The ER is always going to be a weird, folded looking structure attached to the nucleus (rough = has ribosomes on it which are usually represented by little dots, smooth = has no ribosomes on it aka no dots)
The GA looks like the ER but it is not going to be attached to the nucleus like the ER is.
The mitochondria is always going to be pill-shaped and have weird folds inside of it.
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: Your brain constantly gets signals from your body which detect the amount of oxygen and carbon dioxide in your blood. Your brain will send signals to the muscles involved in breathing and adjust your breathing rate depending on how active you are.
HOPE THIS HELPED HAVE A WONDERFULL DAY!