How many linkage groups are present in bacteria?

The greater the length of the chromosomes in an organism, the greater the genetic variation. This variation is obtained from which of the following processes?

Given below are two statements: one is labelled as Assertion $(A)$ and the other is labelled as Reason $(R)$.
Assertion $(A)$:
Mendel's law of independent assortment does not hold good for the genes that are located closely on the same chromosome.
Reason $(R)$:
Closely located genes assort independently.
In the light of the above statements,choose the correct answer from the options given below:

Distinguish between: Linkage in Sweet Pea and Linkage in Drosophila.

Linkage groups can be separated during . . . . . . in meiosis.

What will be the number of linkage groups in maize if it has $10$ pairs of chromosomes?