Genetics Notes Day 2 Warm Up – What is the difference between a genotype and a phenotype? Give an example of each.

Bring in your PHOTOS!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! We are doing “Throw Back Thursday” this week!

A diagram that predicts the expected outcome of a genetic cross.

Helps you keep track of traits. Punnett Squares

. Dominant and recessive alleles are represented by letters. Punnett Squares

A capital letter (T) is used for dominant alleles. Punnett Squares

A lowercase letter (t) is used for recessive alleles. Punnett Squares

Example (Tall or short) T = dominant allele t = recessive allele Homozygous dominant – Genotype = _____ Phenotype = __________ Heterozygous – Genotype = _____ Phenotype = __________ Homozygous recessive – Genotype = _____ Phenotype = __________

If you wanted to know the type of offspring a cross between two parents would produce, you can use a punnett square. Tt x Tt TT,Tt for tall Tt for short Punnett Squares

The letters representing the alleles from one parent are placed along the top of the square. T t Punnett Squares

The letters representing the two alleles from the second Parent are places along the side of the square. T t Punnett Squares

T t x T t T t T t Punnett Squares

Squares are filled by writing the letter at the top beside the letter on the side. TT Tt t t T t T t

Punnett Squares The letters in each of the squares represents the Genotypes of the offspring that the parents could produce. TT Tt t t T t T t TT Tt Tt t t

The genotype (genetic makeup) can be used to predict the phenotype (physical appearance) of the offspring. Punnett Squares

Genotype Phenotype TT tall Tt tall t t short Punnett Sqaures

Punnett Squares Probability: the ratio that a particular event could occur. out of 4 offspring 3 would be tall 1 would be short

Punnett Squares: Help you keep track of traits. Predict genotype and phenotype. Calculate probability.

Bb BB x bb bb B Genotypes: Bb, Bb, Bb, Bb Phenotypes: All brown Probability: 100%

BBBb BB Bb BB x Bb Bb B Genotypes: BB, BB, Bb, Bb Phenotypes: All brown Probability: 100% brown

Genetics Notes Day 3 Warm Up: Create a Monohybrid cross from these parents: Dad = heterozygous for Brown Eyes Mom = homozygous recessive for Blue Eyes

Bbbb Bbbb B b b b

Dihybrid Crosses A cross that involves two pairs of contrasting traits. – RrYy crossed with RrYy – RY Ry rY ry

BBffx BBFF BfBfBfBf BFBFBFBF

TtrrxttRr TrTrtrtr tRtrtRtr