During the woman's menstrual period.
Answer:
(a) an aquaporin
Explanation:
An aquaporin is a water channel which forms a pore in the cell membrane and facilitates the movement of water. Aquaporin is an integral membrane protein (permanently attached to the membrane) that enables the in and out flow of the water. This channel also prevents the passage of ions and other solutes, so it cannot change the voltage. There are four types of aquaporins, and they are mostly found in the kidney with the function of water reabsorption.
There are two main reasons why cells divide rather than continuing to grow larger and larger. One of the main reason is that the larger cell become more demanding, therefore the large cell will increase load on the machinery of the cell such as DNA. The other reason is that if the cell grow too large it will be difficult for the cell to move for nutrients and discard the waste across the cell membrane. Also the surface area for each cell will also be reduced, which is required for active functionality of a cell.
Mitochondrial DNA can be traced for generations. It is because of the fact that unlike nuclear DNA, mitochondrial DNA rarely gets mutated. The frequency of mutations in the mitochondrial DNA is approximately one every 3,500 years per nucleotide. That is why mitochondrial DNA of a person is almost similar to his/her direct maternal ancestor. So, it can be used to match lineages amongst people.
The correct option is B. 80% of the radioactive phosphorus used in the experiment entered the cell showing that DNA was the hereditary material.
