Transcript Genotype and Phenotype

GENOTYPE AND PHENOTYPE
You’re up in
arms over it
Fire Engine
Breakfast
GENOTYPE AND PHENOTYPE
Target: I will be able to use the principles of dominance to
identify the phenotype given a genotype.
Homozygous: When an organism has two of the same
alleles for a certain trait.
For example TT, tt.
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Heterozygous: When an organism has two different
alleles for a certain trait.
For example Tt.
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Genotype: Combinations of gene alleles in an individual.
TT, Tt, or tt.
Phenotype: Physical expression of genes that determine
an individual’s appearance.
Tall or Short.
•Two organisms can have the same phenotype but different
genotypes.
•For example: Both individuals can have Brown eyes,
but one can be homozygous (BB) and one can be
heterozygous (Bb).
Lets practice!
Trait
Genotype
Phenotype
Handedness
RR
Right Handed
Right = Dominant
Right Handed
Left = Recessive
Rr
rr
Knuckle Hair
Hh
Hairy Knuckles
Hairy = Dominant
hh
Not Hairy Knuckles
HH
Hairy Knuckles
dd
DD
No Dimples
Dimples
Dimples
No Hair = Recessive
Cheeks
Dimples = Dominant
No Dimples= Recessive
Dd
Left Handed
Examples of Inheritable Traits:
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Hairline
Eye Color
Tongue Rolling
Earlobes
Hitchhiker Thumbs
Thumb Crossing
Bent Pinky Finger
Genotype: Combinations of gene alleles in an individual.
TT, Tt, or tt.
Phenotype: Physical expression of genes that determine an
individual’s appearance.
Tall or Short.
•Two organisms can have the same phenotype but different
genotypes. Examples – Tt – tall, TT – tall
For example: Both individuals can have Brown eyes, but
one can be homozygous (BB) and one can be
heterozygous (Bb).
Summary:
STUDYING MY GENES
1. With a partner go through the Studying my Genes Worksheet, helping
each other decide which alleles they have and what the genotypes and
phenotypes are.
2. Count up their amount of dominant/recessive alleles you have and
answer the first question at the bottom of the page.
3. Then using the class data, answer the second question.
4. Finish the worksheet by analyzing what it truly means to be dominant
(question #3)
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