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 ID: 497456
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Slide1
Mendel’s Punnett SquaresSlide2
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, GraySlide3
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 letterA genotype= is the actual allele combination (Aa, AA, aa)A phenotype= is what trait that expresses (Tall or Short)Slide4
Types of genotypes and phenotypes
If an individual is purebred=homozygous
If an individual is homozygous dominant= AA
If an individual is homozygous recessive= aaIf an individual is heterozygous= Aa PhenotypesHomo Dom. and Heterozygous expresses dom allele
Homo Rec. expresses recessive alleleSlide5
Genotypes and Phenotypes Example
Eye color
The allele for blue eye color is ‘b’
The allele for brown eye color is ‘B’ What is the phenotype of picture A? What is it’s genotype?What is the phenetype
of picture B? What is its genotype?
A
BSlide6
Getting a phenotype from a Genotype
Eye color
The allele for blue eye color is ‘b’
The allele for brown eye color is ‘B’ What is phenotype of Bb?What is the phenotype of bb?
What is the phenotype of BB?Slide7
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:
BB-
Bb-
bb-
What are the ratios of phenotypes:
Blue eyes-
Brown eyes-Slide8
3 Possible Monohybrid Crosses
Type 1
AA x aa
Phenotype ratios:Genotype ratiosSlide9
3 Possible Monohybrid Crosses
Type 2
AA x Aa
Phenotype ratios:Genotype ratiosSlide10
3 Possible Monohybrid Crosses
Type 3
Aa x Aa
Phenotype ratios:Genotype ratiosSlide11
3 Possible Monohybrid Crosses
Type 4
Aa x aa
Phenotype ratios:Genotype ratiosSlide12