Genetics quiz Monday, January 26

Dihybrid Cross TtRr x TtRr

Dihybrid Crosses Mendel noticed how one trait is inherited does not affect how the other trait is inherited is independent assortment

Dihybrid cross have two separate traits Make a key (genotypes and phenotypes): RR:red, Tt:Tall Determine what alleles each parent can put into each gamete Foil method is an easy way (TtRr) Put the genotype for each parent across the top and side Keep alleles of the same trait together Put dominant allele first for dihybrid when filling in the cross/square

Dihybrid Crosses. Consider all possible gametes for an individual, then perform the cross. Practice: cross two heterozygotes for pea color and flower color. PpYy x PpYy Take a minute and figure out the possible gametes. PY Py pY py

Dihybrid Crosses. In order to accomplish this you must consider all possible gametes for an individual, then perform the cross. Let’s try crossing two heterozygotes for pea color and flower color. PpYy x PpYy… Conduct the cross, calculate probabilities. PYPypYpy PY Py pY py

Dihybrid Cross BbRr x BbRr Fur Color: B: Black b: White Coat Texture: R: Rough r: Smooth

Dihybrid Cross BbRr x BbRr Possible gametes: BR Br bR br

Dihybrid Crosses: a cross that shows the possible offspring for two traits Fur Color: B: Black b: White Coat Texture: R: Rough r: Smooth BbRr x BbRr BR bR br bR Br BR br Br

BR bR br bR Br BR br Br BBRRBbRRBbRr BBRrBBrrBbRrBbrr BbRRBbRrbbRRbbRr BbRrBbrrbbRrbbrr BBRr How many of the offspring would have black, rough coat? How many of the offspring would have a black, smooth coat? How many of the offspring would have a white, rough coat? How many of the offspring would have a white, smooth coat? Fur Color: B: Black b: White Coat Texture: R: Rough r: Smooth Phenotypic Ratio 9:3:3:1

Sea world worksheet Punnett Square Exercises

Homework Pearsonsuccessnet.com Read section 11-3 Exploring Mendel Genetics

In pea plants, yellow seeds (Y) are dominant over green seeds (y), and rounded peas (R) are dominant over wrinkled peas (r). Cross a plant that is heterozygous for both traits with a plant that is homozygous recessive for both traits. Draw a Punnett square to show all possible offspring, and determine the genotypic and phenotypic ratios.

YyRr X yyrr YR yR yr Yr YyRryyRryyrr YyRrYyrryyRryyrr YyRrYyrryyRryyrr YyRrYyrryyRryyrr Yyrr