Question

Genes are packed in bacterial chromosome by
A) Acid proteins
B) Histones
C) Basic proteins
D) Actin

Answer 1

Hint:Though the bacteria do not have defined nucleus, the DNA is not scattered throughout the cell. DNA of bacteria is highly negatively charged which is held with some proteins (having positive charges ) in a region termed as nucleoid.

Complete Answer:
Bacteria are also called as prokaryotic cells due to the presence of a primitive type of nucleus devoid of nuclear membrane. Thus they are termed as nucleoid. The bacterial chromosome is having circular DNA containing the entire genome within it. Since, the bacterial DNA are negatively charged , they are held with some proteins that are basic in nature and are positively charged. Sometimes, apart from the circular DNA extra circles are also found that are termed as plasmids.

Additional information:In eukaryotic cells, there is a set of positively charged basic proteins called histones. This protein acquires charge depending upon the abundance of amino acids residues with charged side chains. Histones are rich in the basic amino acids residues like lysine and arginine. These histones are organized to form a unit of eight molecules called histone octamers.

Thus the correct option is ‘C’ i.e. basic proteins.

Note:In bacteria, the adjacent bases are linked by phosphate groups each with an ionized hydroxyl group. Due to this, there is negative charge developed in chromosomes which are balanced by an equivalent number of positive charged molecules. These positive charged molecules are neutralized by polyamines like spermine, spermidine and $Mg^2+$ ion. These DNA in the nucleoid is organized in large loops held by basic proteins.