Mendel and the History of Genetics

Gregor Mendel

Born 1822

Began his work at age 21

A monk and school teacher interested in plant breeding

Studied pea plants

Discovered the basic principles of heredity

Mendel’s StudiesPea plants were an ideal choice for

study

Displayed seven traits in one of two contrasting forms:

• seed shape• seed color• seed coat color• pod shape• pod color• flower position• stem length

Mendel’s Pea Plant

1

5

4

3

2

Removed stamensfrom purple flower

Transferred sperm-bearing pollen fromstamens of white flower to egg-bearing carpel of purple flower

Parentalgeneration(P)

Pollinated carpelmatured into pod

Carpel(female)

Stamens(male)

Planted seedsfrom pod

Examinedoffspring:all purpleflowers

Firstgenerationoffspring(F1)

Mendel’s monohybrid

crosses

Crossed male pea parts (stamens) and female pea parts (carpels) with opposite traits

Carpel matures to first-generation offspring (F1)=

PURPLE FLOWERS

Mendel’s Procedure