Genetics

Genetics is the study of genes, genetic variation, and heredity in living organisms.^[1][2] It is generally considered a field of biology, but intersects frequently with many other life sciences and is strongly linked with the study of information systems.

The father of genetics is Gregor Mendel, a late 19th-century scientist and Augustinian friar. Mendel studied "trait inheritance", patterns in the way traits are handed down from parents to offspring. He observed that organisms (pea plants) inherit traits by way of discrete "units of inheritance". This term, still used today, is a somewhat ambiguous definition of what is referred to as a gene.

Trait inheritance and molecular inheritance mechanisms of genes are still primary principles of genetics in the 21st century, but modern genetics has expanded beyond inheritance to studying the function and behavior of genes. Gene structure and function, variation, and distribution are studied within the context of the cell, the organism (e.g. dominance), and within the context of a population. Genetics has given rise to a number of subfields, including epigenetics and population genetics. Organisms studied within the broad field span the domains of life (archaea, bacteria, and eukarya).

Conjugation is a mating process between two bacteria and involves physical contact and transfer of genetic material from one bacterium to another.

In transformation, bacteria pick DNA from the environment, from different sources mostly from dead bacterial cells, when the growth conditions are favorable. The newly acquired DNA is single stranded, and can recombine with the host chromosome.

In transduction, a viral phage infects bacteria and injects its DNA into the bacterial cell. The viral DNA digests the host, replicates many times and then burst out of the cell to infect other cells.