An overview of Gregor Johann Mendel and his experiments

Gregor Johann Mendel is known as the Father of Genetics. Actually he was a meteorologist, mathematician, biologist and a monk. Mendel observed variations in the field of pea. By seeing these variations, he decided to know the real facts of these variations.

Mendel discovered the basic principles of heredity through experiments . His experiments showed the inheritance of certain traits in pea plants. He founded modern genetics and led to the study of heredity.

He conducted his experiments on the Garden Pea plant or Pisum sativum. He selected fourteen true breeding plants of Pea and considered seven contrasting characters in pea plants. These seven characters are as follows- 

Seed  Shape -round or wrinkled

Seed  color -  green or yellow

Pod shape - constricted or inflated

Pod color -green or yellow

Flower color - purple or white)

Plant size - tall or dwarf 

Position of flowers - axial or terminal.

Facts about Mendel's Experiments 

Mendels took Fourteen true breeding plants. Mendel considered seven contrasting characters during his experiments. Mendel considered only Single characters at once during his experiments. He was first to use Mathematics in Biology. Mendels was lucky because there was no linkage phenomenon in pea plants. 

👌👌Remember - Mendel coined the term dominant and recessive.

Selection of Pea Plant for Experiments 

Pea plant is an annual plant with a short life span so several generations can be studied in a short period. It is perfect bisexual flower containing both male and female reproductive flowers.It easily self pollinated and also  cross pollinated by doing the emasculation. It produces a large number of seeds in one generation. Pea plants are easily handled and maintained.

Mendel's observation and inference

The characters that are controlled in pea plants are coded by some factors. These factors are passed from one generation to another generation without any changes. These factors are found in pairs.

The hybrid or offspring show combined characters of parental form. The traits also  appeared in another generation without any change. The two contrasting traits do not show any blending or mixing in any generation.

Terms used in Mendel's experiments and observation

Mendel conducted a cross between a single trait called monohybrid cross and also between two traits called dihybrid cross.

Mendel used the term allele for coding the traits that are similar in homozygous like AA  or dissimilar in heterozygous like Aa.

He analysed two types of ratio during his result. First, the ratio of external appearance in pea plants is called phenotypic ratio and the second ratio of allelic forms is called genotypic ratio.

A British scientist Reginald C Punnett developed a square to calculate the genotypic and phenotypic ratio called Punnett Square or CheckerBoard.