1. GENETICS VOCABULARY

2. WHAT IS HEREDITY?
The passing down of genes from parent to offspring

3. What are genes?
Segment of DNA Determines a trait Trait is shown as a protein

4. Are all genes the same?
A trait is a physical characteristic of your body:
Hair Color
Height
Widows Peak
Hitchhiker’s Thumb
Are all the traits the same?

5. Alleles Different forms of a gene Usually represented by a letter.
Each person gets two alleles for a gene ( one from mom/ one from dad)

6. What do alleles mean? Genotype- Combination of alleles in a person
The letters
Phenotype
What trait the alleles show

7. Genotype forms Homozygous- Heterozygous Two of the same allele
Two different alleles in a genotype

8. Examples- Mendel and his peas
Was a monk
Worked with peas to look at inheritance
Was able to develop rules of inheritance

9. Mendel’s findings 1. Each person has two genes
2. Those genes can be different
3. Only one gene from each parent

10. Breeding experiments Determined some relationships between genes
DOMINANT ALLELE-
The trait will be expressed if this allele is present
Usually it is the capital letter
RECESSIVE ALLELE-
The trait will only show up in phenotype if both alleles are present
Usually it is the lower case letter

11. Dominant does not always mean allot!
Polydactyly-
Having extra fingers
Due to two dominant alleles
Not seen allot in population