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To Be Completed:
Today’s Lesson:
Review Understanding Inheritance
DI: Genotypes
All sexually reproducing organisms have 2 parents
Genotypes are written showing 2 alleles
(one inherited from each parent)
Ex. Bb, TT, tt
What symbols should be used?
Use the first letter of the dominant phenotype (form)
Use the same letter for both dominant and recessive phenotypes
Uppercase - dominant
Lowercase - recessive
Dominant alleles are always written first
Write only genotypes to match the phenotypes of the individual.
Write two allele symbols for each genotype.
Homozygous - both alleles are the same (either dominant or recessive)
Heterozygous - one allele is dominant and the other is recessive
Dominant phenotypes can be homozygous - RR or heterozygous Rr
Either way the dominant allele shows (expresses)
Recessive phenotypes are always homozygous - rr
Any dominant allele would mask the recessive