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

Genetics! There is only one YOU!

You Do- How are these people different?

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

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).

Different Alleles in flies

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

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

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

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?

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

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?

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

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

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

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

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