1. GENETICS DOMINANT/ RECESSIVE NOTES

2. DEFINITIONS  Heredity – the passing on of traits from parents to their young  Genetics – branch of biology that studies heredity  Traits – specific characteristics that vary from one individual to another

3. GREGOR MENDEL  A monk who lived in the 19 th century and revolutionized genetics with his ideas about how traits are inherited by doing experiments with pea plants  Known as “The Father of Genetics”

4. DEFINITIONS  Self-pollination (True-breeding)  Getting characteristics from 1 parent  Produces a purebred  Cross-pollination  Getting characteristics from 2 different parents  Produces a hybrid

5. 2 Conclusions from Mendel’s work:  1. Individual factors control each trait Genes – factors that control traits (ex. Height) Alleles – different forms of a gene (ex. Tall & Short)

6. 2 Conclusions from Mendel’s work:  2. Principle of Dominance – some factors are dominant & some are recessive Dominant – effects of these genes are seen when 2 different alleles are present Recessive – form of a gene not expressed when paired with a dominant allele (only seen when another recessive allele is present)

7. DEFINITIONS  Genotype – genetic makeup Ex. TT, Tt or tt  Phenotype – physical characteristics (what they look like) Ex. Tall, short

8. DEFINITIONS  Homozygous – organism that has 2 identical alleles for a trait Ex. TT or tt  Heterozygous – organism that has 2 different alleles for a trait Ex. Tt