What is centromere?write short note.
Answers
Answer:
Function of Centromere
All living things are made up of cells. In order for cells to grow or reproduce, cell division must occur. In cell division, one “parent” cell splits in two, with each of the resulting cells being “daughter” cells.
For each daughter cell to survive, it is essential that they get a copy of each of their parent cells’ chromosomes.
When this does not happen, and daughter cells receive incomplete information, or too many copies of one chromosome, serious disease or cell death can result.
To ensure that a full copy of its DNA is given to each daughter cell, a cell first makes a complete copy of its DNA. The two copies stick together, ultimately condensing to form sister chromatids, until they are pulled apart during cell division.
The centromere of the chromosome provides a binding site for the mitotic spindle fiber that will attach to each sister chromatid and pull them to opposite ends of the parent cell, which will ultimately become the cytoplasm of the two daughter cells. Epigenetic marks” are chemical changes made to DNA by enzymes, which can change the DNA’s chemical properties and other properties. Epigenetic marks can be added or removed without changing information contained in the DNA.
Explanation:
The centromere is the specialized DNA sequence of a chromosome that links a pair of sister chromatids (a dyad).[1] During mitosis, spindle fibers attach to the centromere via the kinetochore.[2] Centromeres were first thought to be genetic loci that direct the behavior of chromosomes.
The physical role of the centromere is to act as the site of assembly of the kinetochores – a highly complex multiprotein structure that is responsible for the actual events of chromosome segregation – i.e. binding microtubules and signalling to the cell cycle machinery when all chromosomes have adopted correct attachments to the spindle, so that it is safe for cell division to proceed to completion and for cells to enter anaphase.[3]