Lecture 19 Basics: Beyond simple dominance
Incomplete Dominance:
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Molecular biology of incomplete dominance:
The heterozygote is pink because:
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Codominance:
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Molecular biology of codominance:
Codominance and simple dominance in one gene:
In codominance (IA IB):
In simple dominance (IB i):
Blood genotypes and phenotypes:
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Multiple alleles:
Epistasis:
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Overview:
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The BB genotype
The bb genotype
The heterozygote Bb:
The EE or Ee genotype:
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The ee genotype:
Pleiotropy:
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Polygenic inheritance:
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Class Notes:
Sixteen alleles are known to exist for a given gene in a diploid organism. This means that any given
individual of that species can have:
A. Up to 16 chromosomes with that gene
B. Up to 16 genes for that trait
C. A haploid number of 8 chromosomes
D. Up to 16 different traits
E. At most, 2 alleles for that gene
If two parents have children of all four blood types, what must the parental phenotypes be?
A. One is A; one is B
B. Both are AB
C. One parent can be O
D. Neither parent can be AB
The incompletely dominant gene for snapdragon flower color has two alleles, “Cr” and “Cw.” Two
fluorescent markers are made with binding sites for the mRNA and the protein produced by the gene. If
the markers are added to a cell within the pea flower petal, draw the amount of fluorescence seen in the
remaining genotypes:
Mouse coat color depends on two genes. The epistatic gene C (color) determines whether pigment will
be deposited in hair (C is dominant to c). The B allele (black) is dominant to the b allele (brown). If two
heterozygous mice are crossed, what proportion of their offspring will be white?
Sperm
BC
bC
Bc
bc
BC
Eggs
bC
Bc
bc
Proportion white: ________________
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