Download CH 11 Introduction to Genetics

CH 11 Introduction to
Genetics
11-1 The Work of Gregor Mendel
Gregor Mendel
Austrian monk born 1822
 Worked at a monastery as
a priest, teacher, and was
in charge of gardening
 Studied the genetics of
ordinary pea plants
 Genetics - scientific study
of heredity

Fertilization
During sexual reproduction,
male and female
reproductive cells join
 Gametes – sex cells
 True-breeding – produce
offspring identical to parents
when self-pollinate
 Mendel was interested in
cross-pollinating plants with
different traits

Genes and Dominance
Trait – a specific characteristic
 Mendel studied 7 traits in pea plants
 Hybrid – offspring of parents with different traits
 Genes – chemical factors that determine traits

Alleles
Different forms of
a gene (e.g.
height can be tall
or short)
 Some alleles are
dominant and
others are
recessive

Names of Generations
P generation – parents
 F1 – first filial, first
generation of offspring
 F2 – second filial,
second generation of
offspring

Segregation
Separation of alleles
 Mendel – “do recessive
alleles disappear when
P generations produce
offspring?”
 No - when F1 offspring
are crossed recessive
alleles reappear in the
F2 generation (25%
show it)
