Control of the Cell Cycle. The karyotype shown below is from a male and contains one X and one much smaller Y chromosome. The depiction of all of the chromosomes in this manner is known as a karyotype. The kinetochore becomes attached to metaphase plate. The nuclear membrane has disintegrated, and the microtubules attach themselves to the centromeres that adjoin pairs of sister chromatids.
We will come back to the S phase shortly. The final preparations for the mitotic phase must be completed before the cell is able to enter the first stage of mitosis. All dividing cells must go through the process of DNA replication.
Stages of Mitosis Mitosis produces two daughter cells with identical genetic material.
Toward the end of the prophase stage, the nuclear envelope breaks down, and the microtubules reach from each cell pole to the cell's equator.
Rounding also occurs in live tissue, as described in the text. This is followed by the G2 phase, when the cell synthesizes proteins and continues to get bigger. First, it completes mitosis, during which the contents of the nucleus are equitably pulled apart and distributed between its two halves.
A human body cell contains 46 chromosomes arranged in 23 pairs.