The Work of Gregor Mendel
11-1
Genetics
Chapter 11 is the start
on our unit of
genetics
Genetics is the
scientific study of
heredity
Genetics is currently
one of the largest
growing subjects in
modern biology
Gregor Mendel
In order to study
genetics, we have to
go back to the first
genetic scientist
Gregor Mendel was
the first scientist to
study genetics
He was an Austrian
Monk who was a high
school teacher
Gregor Mendel
Mendel was also in
charge of the
monastery garden
It was in the garden
that he first started his
work on genetics
Mendel worked with
pea plants for his first
experiments
Mendel’s Peas
To start his
experiments Mendel
looked at the truebreeding pea plants
True-breeding plants
are plants that
produce offspring
identical to themselves
if they self polinate
Mendel’s Peas
With his true breeding
plants he took note of
the characteristics the
plants had
After noting their
characteristics he
cross-bred the plants
with each other to
create hybrid plants
Mendel’s First Hybrid Crosses
Mendel’s First Generation
The first generation
of plants that Mendel
grew as hybrids were
crosses from Truebred plants
The new generation
he named F1
After this he crossed
the F1 generation with
another F1 plant
Mendel’s F2 Generation
Principal of Dominance
When he saw his
results of the second
generation cross
Mendel created the
principal of
dominance
The principal of
dominance states that
some alleles are
dominant over others
Principal of Segregation
During his studies on
his pea plants, Gregor
Mendel also came up
with the idea of
segregation
Segregation, as it is
for biologists, refers to
the separation of
alleles during the
formation of gametes
Principal of Segregation
The diagram to the
right shows the
segregation of the
alleles during the
creation of the
gametes (sex cells)
We should notice that
each gamete only
contains one allele, a
concept that we will
return to with Punnett
Squares