1. Warm up 1. Explain what the purpose of Meiosis is
2. Explain why siblings do not always look alike- be sure to use the words chromosomes and gamete cells

2. Genetics!
There is only one YOU!

3. You Do- How are these people different?

4. Background Every human has 46 chromosmes in their cells’ nucleus’
Genes- Pieces of our chromosomes that give us our characteristics.

5. Allele: Different forms of the same gene
Example) Straight hair Curly Hair
You have 2 alleles for every one of your traits, 1 from your father (from sperm) and 1 from your mother (from egg).

6. Different Alleles in flies

7. Dominant: The “stronger” allele. Always seen in phenotype
Shown with a capital letter.
Ex: B = brown eyes

8. Recessive: The “weaker” allele. Covered by dominant allele
Shown with a lower-case letter.
Ex: b= blue eyes

9. You do Discuss then list 5 different traits a human could have
Now list at least two alleles for each of those traits

10. Phenotype: What are the phenotypes of these individuals?
The PHysical traits a person has. Example: brown hair
We can see phenotype
What are the phenotypes of these individuals?

11. Genotype: The genetic makeup or genes a person has. Example: BB
We can NOT see Genotype

12. You do- Recessive or Dominant
B= brown Eyes b= blue eyes
B (recessive or Dominant allele)
b (recessive or dominant allele)
Bb= what color eyes?
bb= what color eyes?

13. Which of the following statements is true?
A) A person’s genotype determines their phenotype. OR
B) A person’s phenotype determines their genotype.

14. Homozygous Homo means “same.” Which of the following are homozygous?
When a persons has two of the same alleles – either two dominant or two recessive alleles
Ex) BB or bb
Which of the following are homozygous?
BB Bb bb

15. Heterozygous Hetero means “different.”
Having 2 different alleles for a trait.
Which of the following are heterozygous? BB bb Bb

16. B= brown eyes b= blue eyes Copy and fill in the chart below
Genotype
Phenotype
Homozygous
Dominant
Homozygous Recessive
Heterozygous BB
Brown eyes bb
Blue eyes Bb
Brown eyes

17. You Do T= tall t= short Genotype Phenotype Homozygous Recessive
Homozygous dominant
Heterozygous