<em>G1, S and G2 phases are all cumulatively referred to as interphase involving the growth of a cell and the replication of its DNA. Initially in G1 phase, the cell grows physically and increases the volume of both protein and organelles. In S phase, the cell copies its DNA to produce two sister chromatids and replicates its nucleosomes. Finally, G2 phase involves further cell growth and organisation of cellular contents. The S phase of a cell cycle occurs during interphase, before mitosis or meiosis, and is responsible for the synthesis or replication of DNA. In this way, the genetic material of a cell is doubled before it enters mitosis or meiosis, allowing there to be enough DNA to be split into daughter cells. The S phase only begins when the cell has passed the G1 checkpoint and has grown enough to contain double the DNA. S phase is halted by a protein called p16 until this happens.</em>
The structure shown by the red arrow is cell membrane.
In biology, cell membrane refers to the thin layer, which develops the external boundary of a living cell. It has three primary functions, which are as follows:
1. It comprises channels and receptors, which permits particular molecules like nutrients, ions, metabolic components, and wastes to pass between the cell and the outside environment.
2. It prevents toxic components from entering the cell.
3. They distinguish essential but incompatible metabolic procedures conducted within the cell.
Answer:
Explanation:
DNA is deoxyribose nucleic acid. It is a double helical structure. It remains in the coiled form so as to make the information stored in the small region within the cell. The sequence of bases allows the information to be stored in the coded form so as to promote the synthesis of proteins. Complementary base pairing allows the DNA molecule to replicate itself.
