Bacteria communicate and exchange genetic information through extensions of their cell walls called

Plasmids.

Explanation:

Plasmids exchange genetic information and genetic immunities to other bacteria. It is also how antibiotic resistance can spread and proliferate to other bacteria as well.

Pili

Explanation:

The first external structure is the pilus (plural: pili). A pilus is a thin, rigid fiber made of protein that protrudes from the cell surface. The primary function of pili are to attach a bacterial cell to specific surfaces or to other cells. But how does the pilus know exactly what surface to attach to? Along the length of the pilus are adhesin proteins. The word 'adhesin' should remind you of the word 'adhesive' These molecules aid in the attachment of the pilus and are specific to the target surface.

Bordetella pertussis is the bacteria that causes whooping cough. Bordetella has pili coated with adhesins that can identify the mucosal surface of the respiratory tract and will stick to only that surface, allowing it to adhere to and infect those cells.

the diploid number of chromosomes is sometimes represented by the symbol 2n. for the fruit fly, the diploid number is 8, which can be written as 2n = 8, where n represents twice the number of chromosomes in a sperm or egg cell.

there are so many examples for that in different areas, like biology experiment carried out in our lab recently.

here's one link: