Download Dihybrid Crosses Note

Probability and genetics
PROCEDURE:
1. Use 2 pennies, 2 nickels
2. 1 penny and 1 nickel represent 2 pair of genes in a parent. The other penny and nickel represent the same pair of genes
in the other parent.
3. Y = head on the penny (yellow), y = tail on the penny (white) R = head on the nickel (rough), r = tail on the nickel
(smooth)
4. Both parents are heterozygous for both traits. YyRr x YyRr
5. Record the resulting offspring from a Punnett square under the expected probability on your data chart.
6. Toss all four coins (at the same time) 50 times and record results on your data chart.
7. Determine the percentage and record under experimental probability on your data chart.
Dihybrid Crosses
What happens when more than one characteristic is involved in a cross?
Dihybrid Cross-->
Law of Independent assortment
https://www.youtube.com/watch?v=qIGXTJLrLf8&spfreload=10
Mendel's Dihybrid Cross
7. An allele is a form of a gene. In a dihybrid cross HhSs x hhss, how many alleles does
a kitten inherit from the mother? _______
8. How many alleles does a kitten inherit from the father? _______.
9. Gametes, which are sex cells, carry the alleles. Why must a gamete carry one allele
(represented by a letter) from each gene? Meaning, why can’t a gamete carry an “hh”
instead of an “hs” or an “Hh” instead of a “HS?”
Dihybrid Crosses
Bernard really likes growing peas in his garden, but the peas he likes are green. He also likes them to have a wrinkled texture, because he thinks they look much more interesting that way. Please work out a YyRr x YyRr (heterozygous
cross)
Genotypic Ratio:
Phenotypic Ratio:
What is the chance that Bernard will have pea plant offspring that match the phenotype he is looking for (green, wrinkled)?
If Bernard did not receive any pea plants that were green and wrinkled in actuality, would you know for sure that the parent genotypes were incorrect? Why or why not? The Product Rule
Each allele is _______________ of the other, and no two alleles are __________
to each other
When two events are ____________ of each other, the probability that both
events will occur can be calculated using the ___________ ________
The probability of two or more outcomes occurring is equal to the product
of their individual probabilities
What is the probability of giving birth to two boys?
Determine the probability that a plant of genotype CcWw will be produced from the
following cross: CcWw x Ccww
Challenge