Centromere and Chromosome Segregation

Maria James

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A centromere is a district on a chromosome that joins sister chromatids. Sister chromatids are twofold abandoned, duplicated chromosomes that are shaped during cell division. The essential capability of the centromere is to act as the site of connection for shaft strands during cell division. The axle framework lengthens cells and isolates chromosomes to guarantee that each new little girl cell has the right number of chromosomes for the consummation of mitosis and meiosis.

The DNA in the centromere district of the chromosome is comprised of firmly stuffed chromatin called heterochromatin. Heterochromatin is extremely dense and hence not interpreted. In view of its heterochromatin structure, the centromere locale is more profoundly hued with colors than different districts of the chromosome.

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Centromere area

A centromere isn’t generally situated in the focal locale of the chromosome. A chromosome is made out of a short arm district (P arm) and a long arm locale (Q arm) joined to a centromere area. Centromeres can be situated close to the focal locale of a chromosome or at numerous situations along the chromosome.

Metacentric centromeres are situated close to the chromosome community.

Submetacentric centromeres are found non-halfway with the goal that one arm is longer than the other.

Telocentric centromeres are found toward the end or telomere district of a chromosome.

The place of the centromere can be effectively seen in the human karyotype of homologous chromosomes. Chromosome 1 is an illustration of a metacentric centromere, chromosome 5 is an illustration of a submetacentric centromere, and chromosome 13 is an illustration of an acrocentric centromere.

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Chromosome partition in mitosis

Before the beginning of mitosis, the cell enters a stage known as interphase where it reproduces its DNA in anticipation of cell division. Sister chromatids are shaped and joined at their centromere.

In the prophase of mitosis, unique locales on the centromere called kinetochores associate chromosomes to the polar filaments of the axle. Kinetochores are made out of a few protein buildings that create kinetochore filaments, which connect to shaft strands. These filaments help in controlling and isolating chromosomes during cell division.

During metaphase, chromosomes are held in the metaphase plate by powers like polar filaments pushing on the centromere.

During anaphase, the matched centromere in each different chromosome starts to separate as the girl chromosomes are first pulled toward the far edge of the phone.

During telophase, recently shaped cores encompass the singular little girl chromosomes.

After cytokinesis (a division of the cytoplasm), two separate girl cells are framed.

Chromosome division in meiosis

In meiosis, a cell goes through two periods of the division cycle. 

During metaphase, I, the centromeres of homologous chromosomes are arranged towards inverse cell posts. This implies that homologous chromosomes will connect to the fibers reaching out from only one of the two cell posts in their centromere locales.

At the point when the axle fiber abbreviates during anaphase I, homologous chromosomes are pulled towards inverse cell posts however sister chromatids stay together.

In meiosis II, shaft strands reaching out from both cell posts join sister chromatids at their centromere. Sister chromatids separate in anaphase II when axle filaments pull them to inverse shafts.

Meiosis is the consequence of the division, partition, and appropriation of chromosomes among four new little girl cells. Every cell is haploid, containing just a portion of the chromosomes as the parent cell.

Centromere irregularities

Centromeres assume a significant part by taking part in the detachment cycle for chromosomes. Notwithstanding, their construction might make them expected locales for chromosomal modifications. Hence safeguarding the honesty of the centromere is a significant capability for the cell. Centromere peculiarities have been connected to different illnesses like a malignant growth.


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