GREGOR MENDEL

• Gregor mendel (Father of Genetics) started studying inheritance in peas.
• Performed experiments with pea plants for 7 years (1856-1863).
• Proposed laws of inheritance
• Statistical analysis and mathematical logic used.
• He chose pea plant (pisum sativum).
• He proposed the law of inheritance in living organism.

Why mendel selected pea plant for his experiment ?

• Pea plant (Pisum sativum) was easy to cultivate. It grew well in his garden.
• Its flowers were hermaphrodite l.e. pea plant have both male and female sexual organs.
• It is Self pollinated in nature.
• Cross pollination is easy to be done artificially.
• It completes its lifecycle in one season.
• Pea had many sharply distinct, its each trait had two clear cut alternative forr.. or varieties:

E.g. seed shape had a round or wrinkled phenotype, plant height was either tall or short, seed color could be yellow or green etc. Mendel called them pair of contrasting traits. He focused on seven such contrasting pair of traits.

Seven Different Traits:

He traits that Mendel studied are listed below:

•Form of ripe seed (R) – smooth or wrinkled
•Color of seed albumen (Y) – yellow or green
•Color of flower (P) – purple or white
•Form of ripe pods (I) – inflated or constricted
•Color of unripe pods (G) – or yellowce green or yellow
•Position of flowers (A) – axial or terminal
•Length of stem (T) – tall or dwarf

Dominant and Recessive Trait

The following table shows each of the traits and which traits are dominant and which recessive.

F₂ Generations Cross :-

Reason for Mendel’s success

1. Mendel applied statistical method and mathematical logic for analyzing his results.
2. He kept accurate records of his experiment.
3. Mendel experimented on a number of plants for the same trait and obtained hundreds of offspring. and obtained
4. He tried to formulate theoretical explanation for the observed result..