Actively dividing eukaryote cells pass through a series of stages known collectively as the cell cycle: two gap phases (G1 and G2); an S (for synthesis) phase, in which the genetic material is duplicated; and an M phase, in which mitosis partitions the genetic material and the cell divides.
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G1 phase. Metabolic changes prepare the cell for division. At a certain point - the restriction point - the cell is committed to division and moves into the S phase.</span><span>
S phase. DNA synthesis replicates the genetic material. Each chromosome now consists of two sister chromatids.</span><span>
G2 phase. Metabolic changes assemble the cytoplasmic materials necessary for mitosis and cytokinesis.</span><span>
M phase. A nuclear division (mitosis) followed by a cell division (cytokinesis).</span></span>
The period between mitotic divisions - that is, G1, S and G2 - is known as interphase.
<span>Mitosis is a form of eukaryotic cell division that produces two daughter cells with the same genetic component as the parent cell. Chromosomes replicated during the S phase are divided in such a way as to ensure that each daughter cell receives a copy of every chromosome. In actively dividing animal cells, the whole process takes about one hour.</span>
The UV rays cause sun spots due to reaction from the radiation.
Answer:
Earth's second atmosphere was formed when the amount of water vapor in the atmosphere decreased, as water started condensing in liquid form.
Metaphase. During metaphase, spindle fibers attach to the centromere of each pair of sister chromatids The sister chromatids line up at the equator, or center, of the cell. The spindle fibers ensure that sister chromatids will separate and go to different daughter cells when the cell divides
