There is much more fresh water underground than on the surface. A rock layer must be porous and permeable to be a good aquifer. An impermeable layer makes up the bottom of an aquifer. The water table rises and falls with additions or subtractions to the groundwater system.
I. Facilitated diffusion is your answer.
Active transport <span>is the movement of molecules across a cell membrane into a region of higher concentration, this process requires energy. Both osmosis and diffusion are passive transportations which means that they don't require energy.
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Answer: is seen below
Explanation:
Termination will not take place if the strings of A nucleotides following an inverted repeat of rho- independent termination ( which forms an hairpin structure)were deleted. Although, RNA polymerase may pause briefly at the hairpin, the presence of A- U base pairs is needed to destabilize the DNA - RNA interaction and to end transcription. If the string A nucleotides is not present, then transcription of RNA polymerase will continue.
<span>Cells control cell division in order to maintain normal cell function. If something happens to the control of the cell division, the healthy cells will divide uncontrollably. These new cells are cancer cells. </span>
The mutations in three genes are responsible for development of cancers:
1. Mutation in proto-oncogenes. Proto-oncogenes normally signal cells to grow and differentiate. Proto-oncogenes can become oncogenes due to mutations which result in the uncontrollable division of the cells.
2. Mutation in tumor suppressor genes. In normal cells, tumor suppressor genes suppress genes essential for cell cycle and that way they prevent uncontrollable cell division. However, after a mutation in these genes, suppression is lost and the cell may progress to cancer.
3. Mutation in stability genes. In normal cells, they have no role either in cell death or growth, but they control mutation rate. Mutation in stability genes results in situation where all genes, including proto-oncogenes and tumor suppression genes, are more frequently mutated.
