Chapter 10: Patterns of Inheritance

Concept 10.1 Genetics Developed from curiosity about inheritance…

Vocab Trait Genetics Cross Fertilization

Blending Theory Early 1800’s Blue x Red = Purple Purple always produce purple Problems with theory…

Gregor Mendel Austrian Monk Taught High School Biology Mathematician Lived in a Monestary Bred Pea Plants in Garden Crossed generations for 7 years

Mendel’s Theory Particulate Hypothesis –True-breeding –Led to “Genetics” Used self- vs. cross-fertilization

Concept 10.2 Mendel discovered that inheritance follows rules of chance…

Vocab Hybrids Monohybrid cross Allelese Homozygous Heterozygous Dominant Recessive Phenotype Genotype Testcross Dihybrid cross Principle of Segregation Principle of Independent Assortment Generations

Principle of Segregation True breeding=pure (homozygous) True x true = hybrid

Pea Traits: Allele= purple vs. white Dominant= Capital (B) Recessive= Lowercase (b) Homozygous= BB or bb Heterozygous = Bb

Principle of Segregation Alleles separate into different gametes during meiosis…

Probability The mathematical prediction that a specific event will occur! Written as fractions, decimals, or percents!

Genotype vs. Phenotype Genotype= Gene Combination (BB, Bb, or bb) Phenotype= What it looks like (Black vs. Fawn)

Testcross: Cross between one known parent and one unknown parent to determine the genotype of the unknown.

10.4 Meiosis Explains Mendel

Chromosome Theory of Inheritance Genes are located on chromosomes Chromosome behavior accounts for inheritance Chromosomes undergo segregation and independent assortment

Reminder…Karyotype

Gene Locus Each gene has a specific location on each chromsome

Genetic Linkage Same chromosome = genes linked –Unless crossing over occurs Blue eyes paired with blonde hair Brown eyes paired with brown hair

10.5 Sex-linked traits have unique inheritance patterns…

Sex Linked Genes A gene that is located on the sex chromosome Discovered by Thomas Hunt Morgan –Studied eye color in fruit flies Result in unusual inheritance ratios (patterns)

Sex-Linked Disorders Red-green color blindness, hemophilia, male pattern baldness, etc. Recessive traits more common in men! –Usually allele is absent on the y chromosome