1. Genotype And Phenotype

2. You’re up in arms over it
Fire Engine
Breakfast

3. 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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4. Heterozygous: When an organism has two different alleles for a certain trait.
For example Tt.
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5. 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.

6. 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!

7. RR Right Handed Rr Right Handed rr Left Handed Hh Hairy Knuckles
Trait
Genotype
Phenotype
Handedness
Right = Dominant
Left = Recessive
Knuckle Hair
Hairy = Dominant
No Hair = Recessive
Cheeks
Dimples = Dominant
No Dimples= Recessive RR
Right Handed Rr
Right Handed rr
Left Handed Hh
Hairy Knuckles
Not Hairy Knuckles hh
Hairy Knuckles HH dd
No Dimples DD
Dimples Dd
Dimples

8. BBWw aabb bbWW Bushy Eyebrows, Ability to winks both eyes
Trait
Eyebrows (B/b)
Bushy = Dominant
Fine = Recessive
Eye Shape (A/a)
Almond = Dominant
Round= Recessive
Eye Winking (W/w)
Both eyes = Dominant
1 eye = Recessive
Genotype
Phenotype
Bushy Eyebrows, Ability to winks both eyes
BBWw
Round eyes, Only winks 1 eye
aabb
Fine eyebrows, Ability to winks both eyes
bbWW

9. Summary: Examples of Inheritable Traits: Hairline Eye Color
Tongue Rolling
Earlobes
Hitchhiker Thumbs
Thumb Crossing
Bent Pinky Finger
Summary:

10. 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. Remember: If you have the dominant trait, only write 1 capital letter in the genotype column since we don’t know if you are homozygous or heterozygous. If you have the recessive trait, you should write 2 lowercase letters 2. Count up their amount of dominant/recessive alleles you have and answer the first question at the bottom of the page. 3. Then count up how many students in the class have each trait and use 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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