booklet project – genetics review fold four blank pages together the cover should say genetics and...
TRANSCRIPT
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