Multiple alleles Polygenic traits Incomplete dominance Autosomal inheritance
Notes: Incomplete Dominance Phenotype is affected by · PDF filePhenotype can depend on...
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Transcript of Notes: Incomplete Dominance Phenotype is affected by · PDF filePhenotype can depend on...
![Page 1: Notes: Incomplete Dominance Phenotype is affected by · PDF filePhenotype can depend on interactions of alleles. •In incomplete dominance, neither allele is completely dominant nor](https://reader031.fdocuments.us/reader031/viewer/2022020302/5a7dd7617f8b9a563b8dffe3/html5/thumbnails/1.jpg)
Notes: Incomplete Dominance Phenotype is affected by many different factors.
![Page 2: Notes: Incomplete Dominance Phenotype is affected by · PDF filePhenotype can depend on interactions of alleles. •In incomplete dominance, neither allele is completely dominant nor](https://reader031.fdocuments.us/reader031/viewer/2022020302/5a7dd7617f8b9a563b8dffe3/html5/thumbnails/2.jpg)
Phenotype can depend on interactions of alleles.
• In incomplete dominance, neither allele is completely dominant nor completely recessive.
– Heterozygous phenotype is a blend between the two homozygous phenotypes
– Homozygous parental phenotypes not seen in F1 offspring
![Page 3: Notes: Incomplete Dominance Phenotype is affected by · PDF filePhenotype can depend on interactions of alleles. •In incomplete dominance, neither allele is completely dominant nor](https://reader031.fdocuments.us/reader031/viewer/2022020302/5a7dd7617f8b9a563b8dffe3/html5/thumbnails/3.jpg)
Four o’clock plants aka Carnations
• Homozygous plants are either red (RR) or white (R’R’).
• Heterozygous (RR’) are pink.
![Page 4: Notes: Incomplete Dominance Phenotype is affected by · PDF filePhenotype can depend on interactions of alleles. •In incomplete dominance, neither allele is completely dominant nor](https://reader031.fdocuments.us/reader031/viewer/2022020302/5a7dd7617f8b9a563b8dffe3/html5/thumbnails/4.jpg)
This animation shows the cross between a black homozygous
dominant cat and a white homozygous recessive cat. This
results in a litter of all heterozygous gray cats.
![Page 5: Notes: Incomplete Dominance Phenotype is affected by · PDF filePhenotype can depend on interactions of alleles. •In incomplete dominance, neither allele is completely dominant nor](https://reader031.fdocuments.us/reader031/viewer/2022020302/5a7dd7617f8b9a563b8dffe3/html5/thumbnails/5.jpg)
• Codominant alleles will both be completely expressed.
– Codominant alleles are neither dominant nor recessive.
– The ABO blood types result from codominant alleles.
![Page 6: Notes: Incomplete Dominance Phenotype is affected by · PDF filePhenotype can depend on interactions of alleles. •In incomplete dominance, neither allele is completely dominant nor](https://reader031.fdocuments.us/reader031/viewer/2022020302/5a7dd7617f8b9a563b8dffe3/html5/thumbnails/6.jpg)
This animation shows the cross between a black homozygous recessive cat and a white homozygous dominant cat. This results in a heterozygous litter of black and white spotted kittens.
Codominance
![Page 7: Notes: Incomplete Dominance Phenotype is affected by · PDF filePhenotype can depend on interactions of alleles. •In incomplete dominance, neither allele is completely dominant nor](https://reader031.fdocuments.us/reader031/viewer/2022020302/5a7dd7617f8b9a563b8dffe3/html5/thumbnails/7.jpg)
• Multiple alleles: exists when genes have more than two alleles
– The ABO blood types result from multiple alleles that are codominant
![Page 8: Notes: Incomplete Dominance Phenotype is affected by · PDF filePhenotype can depend on interactions of alleles. •In incomplete dominance, neither allele is completely dominant nor](https://reader031.fdocuments.us/reader031/viewer/2022020302/5a7dd7617f8b9a563b8dffe3/html5/thumbnails/8.jpg)
Many genes may interact to produce one trait.
• Polygenic traits are produced by two or more genes.
Order of dominance: brown > green > blue.
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• An epistatic gene can interfere with other genes by overshadowing them for a particular trait.
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Labrador Retriever Genetics
• Black is dominant to chocolate B or b
• Yellow is recessive epistatic (when present, it blocks the
expression of the black and chocolate alleles) E or e
Phenotype Possible Genotypes
BBEE BbEE
BBEe BbEe
bbEE bbEe
Bbee Bbee
bbee
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The environment interacts with genotype.
• Examples: • sex of sea turtles depends on both genes and temperature
• Phenotype is a combination of genotype and environment.
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