A cell membrane pump helps human cells to maintain a relatively constant sodium and potassium concentration.
<u>Option: A</u>
<u>Explanation:</u>
Sodium potassium pump is a plasma membrane protein that utilizes energy ATP — Triphosphate Adenosine turning into ADP — Adenosine Diphosphate to deliver intracellular and extracellular sodium (NA+) and potassium (K+) ions sequentially. The purpose of this entire mechanism is to preserve cell equilibrium.
The extracellular medium has a greater concentration of Na while the K concentration of the intracellular fluid is lower. Proteins trap sodium ions in the cytoplasm and pump them out from the cells to preserve cell stability while preserving concentrations. Within the cells proteins inject potassium ions into the cell.
C. It requires active transport because the use of energy is necessary, the natural and opposite flow to this, would be from high to low concentration that requires little to no energy (i.e passive diffusion).
The right answer is freed the hands for other uses.
bipedality is also more economic than tetrapedality, but it is not as fast and does not offer a high jumping skills.
The standing position has an advantage in reproduction because it has become attractive to females and more or less successful imitation in males, depending on their abilities, but bipedalism is a disadvantage in childbirth.
The answer is jackrabbit.
Answer:
The answer is "soda can (about 2 inches)".
Explanation:
In this question, when it is relative to the having the human hair with the d=80 mm (0.003 inches) and the collecting into the structure with the d=700 times larger than itself that will be produced with the coiled of human hair with the d that is = 80 
700 mm= 56,000 or 2.16 inches, that's why the answer is a soda can's which is equal to about 2 inches.
