Primary succession is much slower than secondary succession because it begins where there is no soil. It can take several hundred to several thousand years to produce fertile soil naturally. The first pioneer species to colonize the bare rock will probably be bacteria and lichens, which can live without the soil.
· In an open system matter and energy can be transferred
· In a closed system only energy can be exchanged
· In an isolated system neither matter nor energy can be exchanged
· The cell has to be an open system because it needs to exchange matter and energy and the only way to do so is through an open system
· As an open system the cell allows nutrients to enter the cell and waste products to exit the cell
· The cell does this through the use of a semi-permeable membrane
· It needs nutrients in the forms of glucose, ions and many other molecules.
· The nutrients can come into the cell through either passive or active transport
· In passive transport the nutrients naturally move from a higher concentration gradient to a concentration gradient.
· During active transport the particle need to move against the concentration gradient. To do this the cell needs energy to transport the materials. The energy comes in the form of ATP.
A
he cross bred them and learned about recessive and dominate traits
<span>Because cholesterol is only minimally soluble in water (dissolves into the water at small concentrations) it needs to be transported as part of the complex with proteins-lipoproteins. Thus, lipoproteins bound by specific receptors on cell membranes. Lipoproteins, particles that transport cholesterol through the blood, contain lipid-soluble part (located inside the particle) and amphipathic or water-soluble part (one the surface of the particle). There are five types of lipoproteins: chylomicrons, very-low-density lipoprotein (VLDL), intermediate-density lipoprotein (IDL), low-density lipoprotein (LDL), and high-density lipoprotein (HDL).</span> <span>Receptors for the cholesterol (lipoprotein) are located on the surface of a plasma membrane and after the binding of lipoprotein, coated endocytic vesicles are formed from the surface. Those vesicles carry lipoprotein into the cell together with the receptor (internalization). After internalization, the receptors dissociate and recycle to the cell surface.</span>
I think the answer would be B. by reviewing related work done by others.
