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.

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