What is secondary constriction in the chromosome?
Secondary constrictions are the constricted or the narrow region found at any point of the chromosome other than that of centromere (primary constriction). … Secondary constrictions are useful in identifying a chromosome from a set. There are either 0, 1, 2, 3, or 4 secondary constriction sites in a cell at anaphase.
What is the other name of secondary constriction?
Secondary constriction is also known as nucleolar organizer region as NOR is involved in the formation of nucleolus.
Is centromere the primary constriction?
The centromere is identified cytologically as the primary constriction observable during metaphase and the site of attachment of the kinetochore, the proteinaceous structure associated with centromeric chromatin (1).
Which terms describe the primary and secondary constrictions of chromosomes?
‘Chromosomal satellite‘ is the term given to that part of the end of a chromosome that is separated from the rest of the chromosome by a secondary constriction. (The primary constriction refers to the region of the chromosome occupied by the centromere.)
What is primary constriction and secondary constriction?
The centromere of chromosome is known as primary constriction. The chromatids of a chromosome may be attached together by the primary constriction region On the other hand, any other constricted region over a chromosome is called secondary constriction.
Which is true regarding secondary constriction?
-Secondary constrictions are associated with the nucleolus during interphase of cell division and take part in the reorganization of the nucleolus at the end of the cell division. -Secondary constrictions are useful in identifying a chromosome from a set of chromosomes. So, the correct answer is, ‘Synthesis of rRNA.
What is a telomere and what does it do?
A telomere is a repeating DNA sequence (for example, TTAGGG) at the end of the body’s chromosomes. The telomere can reach a length of 15,000 base pairs. Telomeres function by preventing chromosomes from losing base pair sequences at their ends. They also stop chromosomes from fusing to each other.
What is primary constriction?
Primary constriction is the basic centromere by which the early new chromatids (newly formed chromosomes) remain attached to each other. Its capacity is to empower the development of the chromosome during the anaphase phase of the cell division.
Is centromere and centrosome the same thing?
The centromere is the central region of the chromosome which consists of highly constricted DNA. The centrosome is an organelle that serves as the organizing centre of all microtubules in an animal cell.