The main purpose is protection. The lipid bilayer protects the cell from viruses and other threats to the cell. It also maintains homeostasis within the cell by monitoring the amount of substances the enter or exit the cell.
There are so many examples for that in different areas, like biology experiment carried out in our lab recently.
Here's one link: https://www.creative-biogene.com/Robust-Tn5-Transposase-EMQZ1422-1271506-26.html
The replication happens during the S phase.
Sorry but I can’t help you right now but later I’ll try
Answer:
There are three types of life cycles depend on the dominant phase. These are Haplontic, Haplo-diplontic and Diplontic life cycles. The steps shown in the question is of Diplontic type of reproductive cycle. In this type of cycle, dominant phase is the diploid. The haploid phase is only represented by short lived gametes.