During this stage the DNA condenses into chromosomes. During prophase I, homologous chromosomes pair up and exchange sections of DNA. This is called recombination or crossing over. This is followed by metaphase I where the connected pairs of chromosomes align at the middle of the cell.
What happens to the chromosomes during metaphase 1?
In metaphase I, the homologous pairs of chromosomes align on either side of the equatorial plate. … The chromosomes begin moving toward the equator of the cell. During metaphase II, the centromeres of the paired chromatids align along the equatorial plate in both cells.
Do chromosomes condense in metaphase?
Usually, individual chromosomes cannot be observed in the cell nucleus. However, during metaphase of mitosis or meiosis the chromosomes condense and become distinguishable as they align in the center of the dividing cell.
Do chromosomes double in metaphase 1?
The genetic material of the cell is duplicated during S phase of interphase just as it was with mitosis resulting in 46 chromosomes and 92 chromatids during Prophase I and Metaphase I. However, these chromosomes are not arranged in the same way as they were during mitosis.
What happens during metaphase?
During metaphase, the cell’s chromosomes align themselves in the middle of the cell through a type of cellular “tug of war.” The chromosomes, which have been replicated and remain joined at a central point called the centromere, are called sister chromatids.
What happens in metaphase II?
Metaphase II: The paired chromosomes line up. Anaphase II: The chromatids split at the centromere and migrate along the spindle fibers to opposite poles. Telophase II: The cells pinch in the center and divide again. The final outcome is four cells, each with half of the genetic material found in the original.
Why must chromatin condense into chromosomes?
We inherit one set of chromosomes from our mother and from our father, but those sets of chromosomes have been shuffled. So chromosomes need to condense for several reasons: to keep the DNA from snarling, to allow chromosomes to pair, and to allow recombination.