GENETICS VOCABULARY

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

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

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?

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)

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

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

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

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

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

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