What is genetics?

Genetics is the scientific study of genes, i.e. variations in the characteristics -- resemblances and differences -- of organisms and how these characteristics are inherited from generation to generation. Modern genetics is as much concerned with the organism level of this process as it is with the cellular and molecular levels.

What are genes?

A gene is a fuzzy concept which depends upon who is using the term and in what context. For the earliest geneticists, genes were fairly distinct traits or characteristics which could be observed in the whole organism. For the modern molecular biologist or molecular geneticist a more chemical definition of a gene is used which brings in a number of additional concepts. The molecular gene is a definite sequence of bases in the DNA chain which together code for the production of a particular protein.

What is genetic engineering?

Engineering is the technological manipulation of the objects of the natural world in a way that is perceived to be beneficial to people. Traditionally we used the word in the context of inanimate nature: bridges, railways and machines etc. But the term can be used and is used in the context of biology, namely for bioengineering, i.e. modifying or manipulating living organisms. Another term used in place of the term 'genetic engineering' is 'biotechnology'.

Viruses can also act as vectors in genetic engineering. Viruses are infectious particles that contain genetic material to which a new gene can be added. The virus can carry the new gene into a recipient cell in the process of infecting that cell. The virus can also be disabled so that while it can carry a new gene into a cell, it cannot redirect the cell's genetic machines to make thousands of copies of itself.

Transformation: - Transformation is a process by which a cell takes up naked DNA fragment from the environment, incorporates it into its own chromosomal DNA, and finally expresses the trait controlled by the incoming DNA.

Transduction: - Transfer of DNA from one organism to another through a bacteriophage is called transduction.

Examples

1. Transduction from bacterium to bacterium.

2. Transduction from bacteria to Human cells.