Question

What are the methods of genetic recombination in prokaryotes?

Answer 1

Genetic recombination:

1. Genetic recombination is the breaking and reconnecting of chromosomes or chromosome fragments to alter DNA sequences.
2. It also covers the repercussions of such rearrangements, such as the inheritance of novel allele combinations in recombinant chromosome-carrying progeny.
3. Transduction, transformation, and conjugation are three recombination strategies used by bacteria (prokaryotes) to expand their genetic variety.

1. Transduction:

1. The transfer of DNA from one bacterium to another with the help of a virus is known as transduction.
2. When a virus infects a bacterium, it injects its genetic material into the cell and controls the bacterium's DNA, RNA, and protein synthesis machinery.

2. Transformation:

1. Certain bacteria can consume DNA fragments from their surroundings, known as plasmids, and incorporate them into their chromosomes.
2. The bacterium must first enter a stage known as competence, which allows transformation to take place.
3. The bacterium must activate several genes that express the appropriate proteins to acquire competence.
4. Bacteria typically convert DNA from other bacteria of the same species.

3. Conjugation:

1. The bacterial equivalent of sex is conjugation.
2. It entails physical contact between two cells, possibly via a pilus-like bridging structure.
3. A short DNA piece called the F-plasmid must be present in donor cells, but not in the recipient.
4. A single strand of DNA from the F-plasmid is provided by the donor cell and transferred to the recipient.
5. The enzyme DNA polymerase then creates a complementary strand, resulting in the two-stranded DNA structure that is commonly found.
6. The donor may also give chromosomal DNA in addition to the F-plasmid.
7. The donor DNA is combined with the recipient's genome.