How do G1 and G2 of the cell cycle for blastomeres in cleavage differ from G1 and G2 of the cell cycle in growing adult cells, such as skin, liver, blood, and bone cells?

The cell cycle of blastomeres in cleavage does not occur with the duplication of organelles and cytoplasmic components, for this reason it does not present the G1 and G2 phases. The cycle of mature cells needs duplication of the components and cytoplasmic organelles and for this reason, they present phases G1 and G2.

Explanation:

The cleavage of blastometers is one of the stages responsible for embryonic development. It occurs after fertilization. At that time, the male gamete is joined to the male gamete forming a zygote. This zygote is taken to the uterus where it will undergo numerous cleavages, which are mitotic divisions, which occur without the cell changing in size. These divisions form the blastomeres that go a long time without dividing. Those cell divisions that do not show a change in cell size do not have stages G1 and G2 of the cell cycle.

On the other hand, the cell division of mature cells presents the G1 and G2 phases during their cycle. The G1 phase is characterized by the increase in cell size, which occurs because of the duplication of cellular components that are in the cytoplasm, before cell division. The G2 phase, in turn, is also characterized by an increase in cell size, but this time, this difference in size occurs by the duplication of cytoplasmic organelles.

In blastomeres cleavage, the G1 and G2 phase are absent while in adult cells have G1 and G2 phase. The other difference is the short duration of S phase in the blastomeres as compared to somatic cells.

Explanation:

Skin, liver, blood, and bone cells are somatic cells in which mitosis type of cell division occurs. In mitosis, G1 and G2 phase are present while in blastomeres G1 and G2 phase are absent. Blastomeres refers to the division of the cell in the early stages of embyo so they lack G1 and G2 phase and little time for S phase.