Booklet Project – Genetics Review Fold Four blank pages together The cover should say Genetics and include a definition and YOUR NAME 1. Mendelian or Simple Dominance 2. Incomplete Dominance 3. Codominance 4. Sex Linked 5. Pedigree 6. Mendel’s Laws 7. Multiple Alleles and Polygenic

Genetics: The scientific study of heredity YOUR NAME

Mendelian or Simple Dominance Dominant: The gene whose trait shows when it is present Recessive: The trait you do not see unless there are two Homozygous: Two identical alleles Heterozygous: Two different alleles Allele: Different form of a gene True-Breeding: If they self pollinate, they will have offspring identical to themselves (AA or aa) Hybrid: A cross between parents with different traits (Aa)

Mendelian or Simple Dominance Example: Tall (TT) X Short (Tt) Make a punnet square and tell the genotypes and phenotypes 2 Alleles (T and t) 3 Genotypes: TT, Tt and tt 2 Phenotypes (Tall / Short) Draw a picture

Incomplete Dominance Genotype: The genes in an individual (TT Tt tt) Phenotype: How a trait looks Incomplete Dominance: The heterozygous phenotype is somewhere in between the two homozygous phenotypes (Blended or mixture) Neither allele is completely dominant.

Incomplete Dominance Example: Red parent and White parent: offspring of red, white and pink RR and WW Make a punnet square and tell the genotypes and phenotypes 2 Alleles (R and W) 3 Genotypes: RR, WW, RW 3 Phenotypes Red, White, Pink Draw a picture

Codominance Codominance: Both alleles contribute to the phenotype (both are seen - not blended) This is usually described as solid color parents with offspring that are striped or spotted

Co Dominance Example: Blood Type IA, IB, and i Make a punnet square and tell the genotypes and phenotypes 3 Alleles (IA, IB, and i) 6 Genotypes: (IAIA, IAi, IBIB, IBi, IAIB, ii) 4 Phenotypes (types: A, B, AB and O) Draw a picture

Sex Linked Genes Sex Linked Genes: Traits that are inherited through either the X or Y chromosome Affect males more often because they cannot mask an X linked trait with a dominant allele

Sex Linked Genes Example: Color Blindness Make a punnet square and tell the genotypes and phenotypes 2 Alleles (XC, Xc ) 4 Genotypes: XCXC,XC Xc,XCY and XcY 5 Phenotypes (F No Trait, F Carrier, Female with Trait, Male No Trait, and Male with Trait) Draw a picture

Pedigree Pedigree: A chart that show how a trait is inherited in a family. Example: Simple Inheritance

Pedigree Sex Linked Chart Males more often affected

Mendel’s Laws 1. The Law of Segregation: Each gamete gets only one copy of a gene 2. Independent Assortment: Different traits are inherited separately

Multiple Alleles Multiple alleles means that more than two alleles can exist in a population, however each individual still only has two alleles for that trait

Polygenic Trait Some traits are controlled by more than one gene Examples: Eye color and skin color This explains the wide variation in eye and skin color