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GENETICS



       The term genetics was first of all coined by biologist William Bateson in 1906. It may be defined as the scientific study of the mechanism of inheritance and the causes of variation in living organisms.

Heredity or Inheritance

        The transmission of characters, resemblances as well as variations from parents to children is called heredity or inheritance.

Mendel – The Father of Genetics

Gregor Mandel – The Father of Genetics        The principle of inheritance was first of all explained successfully by Mendel. Mendel worked on the garden pea plant. He selected this plant because it contains certain visible traits or characters called contrasting traits or contrasting characters. Contrasting traits are those traits which always appear in two opposing conditions. For example, some plants of garden pea were tall, whereas others were short; some plants had colourful flowers, whereas some had white flowers. In this way Mendel selected 7 pairs of contrasting traits in pea plant and studied the inheritance of these contrasting traits in various generations of pea plant. After studying carefully he came to the conclusion that ‘The various contrasting characters or traits of the pea plants are controlled by certain ‘factors’ and each inherited character is controlled by one ‘factor’.

       So, according to Mendel ‘factors’ are the carriers of hereditary information from one generation of pea plant to the next generation. However now a day the term ‘factor’ is replaced by the term ‘gene’ which was coined by a scientist named Johanssen in 1909.




Test Your Understanding and Answer These Questions:




  1. What is heredity?

  2. What are factors?

  3. Who is known as father of genetics?

  4. Who coined the term genetics and in which year?

  5. Who coined the term gene and in which year?

  6. Define contrasting traits. Give some examples.

  7. Define genetics. What is the contribution of Mendel in this branch of biology?