Meaning of Anaphase
In Greek, Ana means separation. Anaphase is the phase in which the sister chromatids of the duplicated chromosomes are separated by the shortening of the microtubules into kinetochore and are connected to the degradation of the tubulin molecules that hold the sister chromatids together. anaphase simple definition
Sister chromatids are brought to opposite poles of the cell as microtubules shorten. Once the sister chromatids have separated, they are called chromosomes. anaphase simple definition
This double movement separates the groups of chromosomes into different spaces within the dividing cell.
As soon as the chromosomes separate, they begin to de-condense into a network of chromatin fibers, and there is a reconstitution of the organelles that became disorganized at the beginning of cell division. This is the beginning of the phase called telophase, the last phase of cell division.
In rare cases, both chromatids on a duplicated chromosome can bind to microtubules at the same pole and migrate together to this same pole. anaphase simple definition
This process, which causes an error in the distribution of chromosomes between daughter cells, is called nondisjunction. One of the daughter cells has more chromosomes than the other. anaphase simple definition
Meiosis anaphase simple definition
At anaphase I, homologous chromosomes that were paired on the equatorial plate of the cell begin to be pulled by the spindle fibers toward the poles of the cell. Each chromosome has a pair of chromatids joined at the centromere.
At this stage, the cohesin proteins are degraded and the chiasms disappear.
Anaphase II is a process very similar to the anaphase of mitosis, where sister chromatids are separated from duplicated chromosomes. anaphase simple definition
If the gamete that participates in fertilization has received a chromosome more or less due to a disjunction error, the formed embryo may suffer from some disease, such as Down syndrome.
In this disease, the carrier has 3 chromosomes number 21 instead of just 2, one from the father and one from the mother. The third chromosome is the result of chromosomal nondisjunction of pair number 21 when gametes are produced.
Nondisjunction can also occur on the sex chromosomes. A girl who receives an extra X chromosome will have the 44A, XXX karyotype (Triple X syndrome), which will result in mental retardation, for example. anaphase simple definition
A boy may have two Y sex chromosomes, for example, and have the 44A, XYY (double Y) karyotype. anaphase simple definition
