Question

Which of the following is a type of coiling found during mitosis?
A. Plectonemic
B. Paranemic
C. Both A and B
D. None of the above

Answer 1

Hint: Mitosis is a type of division which occurs in somatic cells and in this division, only cells divide whereas the chromosomal number of the cells remains same in the parent as well as daughter cells.

Complete answer:
Mitotic division is also known as indirect cell division or somatic cell division or equational division.
In mitotic divisions, the mature somatic cells divide in such a manner that the number of chromosomes remains constant in daughter cells and in the parent cells. In these divisions, the daughter cells are similar to the parental cell both quantitatively as well as qualitatively and thus division is referred to as equational division.

In the process of plectonemic coiling, the fibrils of chromosomes are intertwined very closely and thus cannot be separated easily. The length of the chromosomes regulates the degree of coiling during cell division. The type of coiling which occurs during the process of mitosis is plectonemic coiling. DNA supercoiling can be defined as the over- or under-winding of the DNA strand, and it can be expressed as strain of one strand on the other strand. There are various enzymes like topoisomerases which have the ability to change the topology of DNA in order to facilitate the functions like replication of DNA or transcription.

The correct answer is (A).

Note: The coiling of the chromosomes is different in both the divisions like mitosis or meiosis.