Question

Chromosomes in a bacterial cell can be 1 – 3 in number and

(a) are always circular

(b) are always linear

(c) can be either circular or linear, but never both within the same cell

(d) can be circular as well as linear within the same cell

Answer 1

Option a is correct

Explanation:

Bacterial cells do not have a nucleus, characteristic of eukaryotic cells. Nuclear material of bacteria lies free in the cell in the form of an irregular, thin, fibrillar and circular single molecule of DNA, called nucleoid or chromatin body.

This DNA, sometimes attached at one or more points to a mesosome, frequently runs parallel to the axis of the cell, Bacteria! DNA is not associated with histone protein and does not coil to form well-defined chromosomes during the multiplication.

In addition to circular DNA, a small amount of subsidiary extrachromosomal DNA is also present as plasmids or episomes.