Genetics – The study of Inheritance Chapter 20 : Section 2 - Genetics – The study of Inheritance

Heredity When traits are passed from parent to offspring

Genetics The study of how traits are passed from parent to offspring

Genes Traits are inherited How about manners?

Genes Small section of DNA on a chromosome (there are thousands) Contains info about a trait

Alleles Remember chromosomes come in pairs (How many pairs?) Genes come in pairs too – one on each chromosome

Dominant and Recessive alleles Combination of alleles determines the trait Pea plants can have purple or white flowers Pea Plant

Dominant and Recessive alleles Purple allele is dominant White allele is recessive P p

Dominant and Recessive alleles If a baby plant gets a Purple allele from one parent and a Purple allele from the other parent------ what color will the flowers be? P P

Dominant and Recessive alleles If a baby plant gets a Purple allele from one parent and a White allele from the other parent------ what color will the flowers be? p P

Dominant and Recessive alleles If a baby plant gets a white allele from one parent and a white allele from the other parent------ what color will the flowers be? p p

VAriation Different ways a trait appears Can be small or large

Mutation A change in a gene or chromosome Can be good Can be neutral Can be bad

Selective Breeding Take those good mutations and control them

Bill Nye Review Clip