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:
dear user nitrogen fixation is so important bcoz of the reasons given above
C or D but I’m leaning more towards D because the maps could show you what kinds of plants and animals lived there that’s the animal could have eaten
The correct answer is: 5) NER recognizes helix distortions, while BER recognizes specific base damage.
DNA damage that occurs as a result of radiation, oxidizing reagents, chemicals and other mutagens can be repaired. Excision repair repairs single strand DNA damage and it includes:
• Nucleotide excision repair (NER)-it detects and repairs types of damage that distort the DNA double helix such as those of UV radiation (thymine dimers); not only the damaged nucleotide(s) are removed but also a surrounding patch of DNA
• Base excision repair (BER)-it detects and removes certain types of damaged bases (small, non-helix-distorting bases); enzyme glycosylase is responsible for this type of repair
<span>D. It is a compound made of twenty-four total atoms of three different elements.</span>
