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.
Answer:
The life cycle of seedless vascular plants alternates between a diploid sporophyte and a haploid gametophyte phase. Seedless vascular plants reproduce through unicellular, haploid spores instead of seeds; the lightweight spores allow for easy dispersion in the wind.
<h3>hope it will help u in understanding..</h3>
D. There are only a week Hydrophobic interactions in the interior of the membrane.