Name:______Date:______Block:______

Genetics Problem Set #6:

Create Your Own Problem

Your tasks:

1. Create your own genetic problem for your classmate to solve.

2. Create an answer key and be ready and able to explain your answer to your classmates.

Criteria for Success

The genetic question includes the following:

  1. A title. The title includes the type of inheritance your problem:
  2. Dominant/Recessive
  3. Incomplete Dominance
  4. Codominance
  5. Sex-linked trait
  6. Content:
  7. The question contains enough information about the parental generation that a classmate can successful solve your problem.
  8. The question asks your classmates to determine one of the following:
  9. Genotypes, and genotypic ratios
  10. Phenotypes and phenotypic ratios
  11. The probability of a specific (phenotypic or genotypic) outcome occurring in the F1 generation.
  12. Fact or Fiction: Let your classmate know if the question is fact or fiction. If it is a fact you must cite your source.

Your solution to the problem should include the following:

  1. Variables: Correctly assign variables based on the pattern of inheritance.
  2. Genotypes: Correctly determine the variables of the P (parental) generation.
  3. Punnett Square: Show all work.
  4. Correctly label the Punnett square with the parental gametes.
  5. Correctly distribute the parental gametes in the Punnett square.
  6. Solution: The solution answers what the question is asking.
  7. The solution is in complete sentences.
  8. The solution states one of the following based on the question:
  9. Genotypes, and genotypic ratios
  10. Phenotypes and phenotypic ratios
  11. The probability of a specific ( phenotypic or genotypic) outcome occurring in the F1 generation.

Example Question:

Hemophilia a Sex-linked Recessive Trait

Hemophilia is a sex-linked recessive trait. Persons with hemophilia are missing a protein necessary for blood to clot normally. Without, medical treatment, a person with hemophilia could die from miner cuts or bruises[1]. A woman, who is a carrier, marries a man that does not have hemophilia. They are now expecting a baby boy. What is the probability that their child will have hemophilia?

[1] Source: Miller, Kenneth, and Joseph Levine. Biology. Saddle Rive, NJ: Prentice Hall, 2006. 350-351.

Example Solution:

Variables:

XC = Normal Blood Clotting

Xc= Allele for Hemophilia

Y= No allele; gene only found of X Chromosome

Parental Genotypes:

Woman: XCXcMan: XCY

Punnett Square:

XC / Xc
XC / XC XC / XC Xc
Y / XC Y / Xc Y

Solution:

There is a 50% chance that the baby will have hemophilia. It is not 25% because the question asks specifically about the couple having a boy. Half of the male offspring in this Punnett Square are affected with hemophilia. (See highlighted square.)