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:
Explanation:The Carnian Pluvial Episode (Late Triassic) was a time of global to a major extinction event and might have been the trigger of the spectacular known delta system by area (1,000,000 km2) in Earth history.
Answer:
81/256
Explanation:
By doing a test cross of albinism and sickle cell anemia you'll see that the probability that one child is unaffected by either conditions will be 9/16. Both children would be 9/16 * 9/16.
Since fraternal twins are developed from two separate fertilization events the probability chance will be independent.
The characteristic best distinguishes glycolysis and the Krebs cycle from the electron transport chain is the amount of ATP produced . In glycolysis net ATp production is 2 ATP and in 1 Kreb's cycle 38 ATP are produced. Hence option A is correct.
Answer: Single cell organisms dont need a respiratory system because oxygen and carbon-dioxe diffuses between their body tissues and the enviorment.