Transcript The Legacy of Gregor Mendel

1.
Why do we not look like a Rhinoceros?
2.
Who is Gregor Mendel?
3.
How is cross pollination differ from self
pollination?
4.
What is meant by dominant and
recessive traits?
The Legacy of Gregor Mendel
Mendel’s Life
A. 1843 gardener in a monastery in Brunn,
Austria.
B. 1851 sent to the Univ of Vienna to study
science & math (statistics).
C. Returned to the monastery noticed that
some pea plants produced tall & short
plants. Other produces yellow or green
seeds.
D. Inheritance - passing of traits by
heredity.
E. Heredity - is the transmission of traits
from parents to their offspring.
Mendel’s Experiments
Experiment
1. Began with PURE for each trait (always produced that trait).
Strain - used to denote all plants for a specific trait.
2. Self pollination - reproduction with a single parent that transfers pollen
from the male part to the female part.
3. Got a plant for each strain, parental generation P1 generation.
Then
4. Cross-pollination - transferred pollen from one P1 plant to P1 another.
5. Next, he recorded how many of each type known as a First filial
generation, F1 generation.
Then
6. Crossed-pollination the F1 generation.
7. Next, he recorded how many of each type known as a second filial
generation F2 generation.
Mendel’s Pea Plants
Meaning of Results
Suggested that something inside the
plant controls expression (factor).
Each trait had two possibilities, tall or
short, green or yellow.
Concluded that each trait resulted in an
interaction of a pair of factors.
Mendel’s Principle’s
1. Principle of Dominance & Recessiveness
 Dominant - One factor in a pair may mask another.
 Recessive - One trait that was masked.
2. Principle of Segregation
 The 2 factors for a characteristics segregated, or
separated, during the formation of eggs & sperms.
3. Principle of Independent Assortment
 Factors for different characteristics are distributed
to reproductive cells independently.