2. BACKGROUND
Gregor Johann Mendel (Austrian: 1822-1884).-born in Peasant family.
School by own efforts.
Become Monk due to poverty.
Become Abbot on 1843, (Head)-Augustinian monastery of St. Thomas
at Brunn, Austria.
Went in 1851 to the University of Vienna, studied natural history and
mathematics for two years. Got interest in Hybridization.
From 1856-1865 conducted experiments on garden pea, published his
findings in 1866 in the “Annual Procedings of the Natural history
Society of Brunn”.
Work not appreciated, died in 1884.
Rediscovered by Hugo De Vries (Netherland), Karl Correns
(Germany) and Erich Von Tshermak (Austria)-1900 and republished in
1901.
Mendel: Father of Genetics.
3.
4. MENDEL’S EXPERIMENT PLANT
• On garden pea (Pisum sativum).
• The pea plant can be easily
grown and maintained.
• They are naturally self-pollinating
but can also be cross-pollinated.
• It is an annual plant, therefore,
many generations can be studied
within a short period of time.
• It has several contrasting
characters.
5. WORKING METHOD:
Working method
Mendel carried out his experiment with
proper planning and his success depends
on the working method he adopted.
Worked on true breeding plant.
He studied single character at a time.
Mendel used all available techniques in
order to avoid cross pollination by
undesirable pollen grains.
He adopted concepts of statistics and
mathematics so as to analyze the results
obtained by him.
Transfer anther to seed plant
Homozygous means to have 2 identical alleles for a trait. Ex. TT or tt True-
breeding pea plants are homozygous.
Heterozygous means to have 2 different alleles for a trait. Ex. Tt Hybrid
plants are heterozygous.
6. Mendel had established true-breeding lines (or pure lines)
of pea plant with different traits for one or more features of
interest (such as tall vs. short height).
He began to investigate how the traits were inherited by
carrying out a series of crosses.
First, he crossed one true-breeding parent to another.
The plants used in this initial cross are called the P
generation, or parental generation.
Mendel collected the seeds from the P generation-cross
and grew them up.
These offspring were called the F1 generation or first filial
generation.
Once Mendel examined the F1 generation plants and
recorded their traits, he let them selffertilize naturally,
producing lots of seeds.
He then collected and grew the seeds from F1 plants to
produce F2 generation or second filial generation. Again, he
carefully examined the plants and recorded their traits.
)Not only recorded phenotype of the plants in each
generation (e.g., tall vs. short),but also, he counted exactly
how many plants with each trait were present.
