Mendels Punnett Squares Genes and Alleles Gene Place

Genes and Alleles Gene: Place on chromosome and determines certain trait Allele: variation of

Mendelian Traits • Each trait 1 gene with 2 variations or 2 alleles •

Types of genotypes and phenotypes • • • If an individual is purebred=homozygous If

Genotypes and Phenotypes Example • Eye color – The allele for blue eye color

Getting a phenotype from a Genotype • Eye color – The allele for blue

Predicting ratios • This is where you are given two individuals an pretending they

3 Possible Monohybrid Crosses Type 1 • AA x aa • Phenotype ratios: •

3 Possible Monohybrid Crosses Type 2 • AA x Aa • Phenotype ratios: •

3 Possible Monohybrid Crosses Type 3 • Aa x Aa • Phenotype ratios: •

3 Possible Monohybrid Crosses Type 4 • Aa x aa • Phenotype ratios: •

Slides: 12

Download presentation

Mendel’s Punnett Squares

Genes and Alleles Gene: Place on chromosome and determines certain trait Allele: variation of that trait Ex: Gene: Eye color Located on 5 th gene from the top Alleles: Brown, Blue, Green, Gray

Mendelian Traits • Each trait 1 gene with 2 variations or 2 alleles • For each allele, 1 is Dominant 1 is Recessive • Dominant has a capital letter while recessive has lower case letter • A genotype= is the actual allele combination (Aa, AA, aa) • A phenotype= is what trait that expresses (Tall or Short)

Types of genotypes and phenotypes • • • If an individual is purebred=homozygous If an individual is homozygous dominant= AA If an individual is homozygous recessive= aa If an individual is heterozygous= Aa Phenotypes – Homo Dom. and Heterozygous expresses dom allele – Homo Rec. expresses recessive allele

Genotypes and Phenotypes Example • Eye color – The allele for blue eye color is ‘b’ – The allele for brown eye color is ‘B’ 1. What is the phenotype of picture A? What is it’s genotype? 2. What is the phenetype of picture B? What is its genotype? • A • B

Getting a phenotype from a Genotype • Eye color – The allele for blue eye color is ‘b’ – The allele for brown eye color is ‘B’ 1. What is phenotype of Bb? 2. What is the phenotype of bb? 3. What is the phenotype of BB?

Predicting ratios • This is where you are given two individuals an pretending they are making a child, but before they make the child they want to the probability of getting a particular trait • Scenario Blue eyed and Brown eyes person with genotypes of ‘bb’ and ‘BB’ What are the ratios of the genotypes: BBBbbb. What are the ratios of phenotypes: Blue eyes. Brown eyes-

3 Possible Monohybrid Crosses Type 1 • AA x aa • Phenotype ratios: • Genotype ratios

3 Possible Monohybrid Crosses Type 2 • AA x Aa • Phenotype ratios: • Genotype ratios

3 Possible Monohybrid Crosses Type 3 • Aa x Aa • Phenotype ratios: • Genotype ratios

3 Possible Monohybrid Crosses Type 4 • Aa x aa • Phenotype ratios: • Genotype ratios