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:
Option A is correct (Alfred Wallace).
Explanation:
Option A is correct (Alfred Wallace).
According to the evolution theory all living species are evolved from a simple life source with the passage of time.
Points of natural selection:
- Genetic variation are passed from generation to generation but environment can cause variations too.
- Individuals in species have gene variation which is due to random mutation
- Those who can not adopt to environment can not have their genes pass to next generation.
- Natural Selection is also called as "Survival of the fittest".
Endoplasmic reticulum isn’t called the control center of the cell
The answer is B
