1. Dominant & Recessive Human Traits

2. Students will be able to analyze traits in the population.
Objective
Students will be able to analyze traits in the population.
Everyone has traits that they inherit from their parents. Each parent sends one allele for each gene. The offspring has a unique combination of traits depending on what is passed down from their parents. We will be looking at traits that only have one dominant and one recessive trait and follow the Law of Dominance. If the person is homozygous dominant, the dominant trait will be shown. If the person is heterozygous, the dominant trait will be shown. If the person is homozygous recessive, the recessive trait will be shown. You will be observing the phenotype. In the future, we will discuss genotypes.

3. Trait: A variation of a phenotypic characteristic
Vocabulary Review
Trait: A variation of a phenotypic characteristic

4. Part of the chromosome that is the unit of heredity.
Vocabulary Review
Gene:
Part of the chromosome that is the unit of heredity.
Allele:
Alternative forms of a gene

5. Vocabulary Review
Dominant Trait:
The trait that always appears in the phenotype if the dominant allele is present in the genotype. (Homozygous dominant or heterozygous organism).

6. Vocabulary Review
Recessive Trait:
The trait that appears in the phenotype only if two recessive alleles are present in the genotype. (Homozygous Recessive)

7. Vocabulary Review Homozygous:
An organism with two of the same alleles for a specific gene.
Heterozygous:
An organism with two different alleles for a specific gene.

8. Vocabulary Review
Phenotype:
An organism’s observable trait or characteristic
Genotype:
An organism’s two allele pair for each gene

9. Human Traits: Tongue Rolling or Not

10. Human Traits: Free or Connected Earlobes

11. Human Traits: Widow’s Peak or Straight

12. Human Traits: Hitchhiker’s Thumb or Straight

13. Human Traits: Cleft Chin or not

14. Human Traits: No Dimples or Dimples

15. Human Traits: Freckles or No Freckles

16. Human Traits: Interlaced Fingers
LEFT Thumb over RIGHT Thumb
RIGHT Thumb over LEFT Thumb

17. Activity: Sample the Class for Traits
Each group will be assigned a set of traits to survey the class sample.
You will total the number of people with each trait.
Circle the trait that had the most representation in the class.

18. Trait 1:
# of Classmates with Trait
Trait 2:
Tongue Rolling
No Tongue Rolling
Free Earlobes
Connected Earlobes
Straight/ No WP
Widow’s Peak
Hitchhiker Thumb
Straight Thumb
Cleft Chin
Flat/No Cleft Chin
Dimples
No Dimples
Freckles
No Freckles
Interlaced: Left
Interlaced: Right

19. Dominant: Tongue Rolling or Not

20. Dominant: Free or Connected Earlobes

21. Dominant: Widow’s Peak or Straight

22. Dominant: Hitchhiker’s Thumb or Straight

23. Dominant: Cleft Chin or not

24. Dominant: No Dimples or Dimples

25. Dominant: Freckles or No Freckles

26. Dominant: Interlaced Fingers
LEFT Thumb over RIGHT Thumb
RIGHT Thumb over LEFT Thumb