Transcript Mendel Organzier w/answers

Mendelian Genetics
Gregor Mendel:
• Austrian Monk
• Born 1822
• Studied statistics in college
• Studied many plants, but famous
for peas and Mendelian Genetics
Mendel observed contrasting
traits in pea plants:
• seed shape
• plant height
• flower color
Mendel’s Experiments
•Mendel grew pure strains for a
single trait (like flower color)
• He crossed the pure strains,
called the parent generation (P1)
• After P1 Mendel cross pollinated
plants to control pollination
Mendel raised several generations of peas and observed:
• some seeds from short plants produced tall plants
• some seeds from plants with purple flowers produced plants
with white flowers
Recessive and Dominant
Traits:
• Trait that showed up in
F1 must be a dominant
gene, because it masked
the other gene
• The trait that did not
appear must have been
the recessive gene.
Offspring of P1 generation showed (pg 311):
• Crosses of P1 produced all one height (tall) called
the F1 generation
• F1 plants self pollinated and he found a 3:1 ratio (3
tall, 1 short) in the offspring. This generation was
called F2.
• Mendel thought “a factor” (gene) must control the
characteristics, and that there must be two factors.
Law of Independent Assortment:
• The genes for different traits are not
connected
• Genes for different traits are
distributed to gametes independently.
Law of Segregation:
• A pair of genes for
one trait is separated
during the formation
of gametes (meiosis).