BIOL 1030H Lecture Notes - Lecture 8: Epistasis, Punnett Square, Gregor Mendel
26 Jun 2018
School
Department
Course
Professor
Early Transmission Genetics
Each of us has his or her own personal genome
•
It differs from all that have existed before and from all that will come after
•
Traits are passed down from generation to generation
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Complicated theory of natural selection as you are losing genetic variation if averaging is true
•
Blending Inheritance
Genes are transmitted from parents to offspring
•
Explains how variation is preserved although it might appear it is lost
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Colour of seeds
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Shape of seeds
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Colour of pod
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Shape of pod
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Colour of flower
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Position of flower
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Gregor mendel studied:
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Modern Transmission of Genetics- Gregor Mendel
In crossing peas the anthers of the female parent are first exposed and then cut off to prevent
self-fertilization
1.
Mature pollen is collected from another flower and deposited on the stigma of the female
parent
2.
After fertilzation a small cloth bas is tied around the fertilzation of the flower to prevent any
other factors
3.
Pea Plant Crossing
Plants grow from true breeding strains with yellow seeds (true breeding x true breeding= same
colour)
•
Crossing two true breeding in the first generation will always result in the yellow seed
•
F2 generation results in 3 yellow seeds and 1 green seed after they have self fertilized
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Yellow vs Seed Traits
Principle of Segregation- talking about seperation of homolgous chromosomes in anaphase 1
AA- homozygous
Aa- recessive
F1 gen- will always be yellow because a dominant alleel is always present because you have to get
A+a and dominant rules
F2 generation- 2 different phenotypes but expected ratio of AA:Aa:aa = 1:2:1 but results in a 3:1
ratio of dominant: recessive phenotypes
Test Cross: testing with a known homozygous can tell you whether the other is homozygous or
heterozygous
The phenotype is not a results of the genes
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It is a result of an intermediate
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Incomplete Dominance
Mendelian Inheritance
March 21, 2018
5:08 PM
Biology 1030 Page 1
Document Summary
Each of us has his or her own personal genome. It differs from all that have existed before and from all that will come after. Traits are passed down from generation to generation. Complicated theory of natural selection as you are losing genetic variation if averaging is true. Explains how variation is preserved although it might appear it is lost. In crossing peas the anthers of the female parent are first exposed and then cut off to prevent self-fertilization. Mature pollen is collected from another flower and deposited on the stigma of the female parent. After fertilzation a small cloth bas is tied around the fertilzation of the flower to prevent any other factors. Plants grow from true breeding strains with yellow seeds (true breeding x true breeding= same colour) Crossing two true breeding in the first generation will always result in the yellow seed.
