Certain human genetic conditions, such as sickle cell anemia, result from single base pair mutations in DNA. Explain how a single base-pair mutant in DNA can alter the structure and, in some cases, the function of a protein.

looks like the answer is     c     to me!

only about ten percent of the energy at one trophic level is passed on to organisms at the next trophic level. the remainder of the energy is used in life processes or lost as heat.

plants absorb water from the soil by osmosis. root hair cells are adapted for this by having a large surface area to speed up osmosis. the absorbed water is transported through the roots to the rest of the plant where it is used for different purposes: it transports dissolved minerals around the plant.