Transcript Gregor Mendel

Mrs. Wharton’s Class
Mendel’s Work
Mendel’s Experiments

Heredity- the passing of physical
characteristics from parent to offspring.

Trait- Each different form of a
characteristic (height, eye color).

Genetics- The scientific study of heredity
Why did Mendel study Pea Plants?

Pea plants are usually self-pollinating,
meaning pollen from a flower lands on the
pistil of the same flower.

Mendel developed a method by which he
cross-pollinated, or “crossed,” pea plants.
Mendel’s Experiment

Mendel crossed two pea plants that
differed in height. He crossed purebred tall
plants with purebred short plants.
In all of Mendel’s crosses, only one form of the trait
appeared in the F1 generation. However, in the F2
generation, the “lost” form of the trait always
reappeared in about one fourth of the plants.
P1
F1

From his results, Mendel reasoned that
individual factors, one from each parent,
control the inheritance of traits.
Terms Con’t.

Fertilization-when a new organism begins to
form

Purebred-when offspring from many generations
have the same trait

Gene- factors control a trait

Allele-different forms of a gene
An organism’s traits are controlled by the
alleles it inherits from its parents.
Some alleles are dominant, while other
alleles are recessive.

Geneticists use a capital letter to represent
a dominant allele and a lowercase version
of the same letter for the recessive allele.
Mendel’s Results
Parent generation (P1)- two alleles in a
purebred tall were crossed with two alleles
in a purebred short
 F1 generation- two hybrids were crossed
 F2 generation- resulted in purebreds and
hybrids!

Types of Traits

Hybrid- an organism that has two different
alleles for a trait.

Dominant-is one whose trait that always
shows up when the allele is present

Recessive- a trait that is hidden every time
a dominant allele is present.
Mendel’s Results
Mendel’s discovery was not recognized
during his lifetime. In 1900, three different
scientists rediscovered Mendel’s work.
Because of his work,
 Mendel is often called the Father of
Genetics.
