Make sure to do all steps.
Work through the following genetics problems and submit their answers as part of the introduction to your lab report. Please show your work! You will not receive full credit for problems that only have an answer! The problems belong in your introduction portion of the lab report.
1. Both a man and a woman are heterozygous for bent little fingers. Bent little fingers are dominant over straight little fingers. What is the chance that their child will have bent little fingers?
2. Both a brother and a sister do not have freckles, but their parents have freckles. Freckles (F) are dominant over no freckles (f). What are the genotypes of the parents?
3. A father is far-sighted, the mother has normal vision, and all five of their children are far-sighted. Being far-sighted (F) is dominant over having normal vision (f). Give the probable genotypes of all persons concerned.
4. A woman is heterozygous for polydactyly (which is a dominant condition in which a person has more than the normal number of fingers and/or toes). The woman has a child with a man who is homozygous normal. What is the chance that their child will have more than ten fingers and/or toes?
5. Sarah can’t curl her tongue – which is a recessive trait. Both of her parents can curl their tongues – which is dominant. Give the genotypes of all persons involved (use T and/or t in the genotypes).
6. A man has type AB blood and his child has type B blood. What are all of the possible blood types of the child’s mother? (Hint: think about the genotypes of blood types. You will need to work more than one Punnett Square.)
7. A child who does not have dimples or freckles is born to a man who has dimples and freckles (both dominant) and a woman who does not. What are the genotypes of all persons concerned?
Try typing in “Baby Steps Through Punnett Squares” in your search engine or try this site:
- Be sure to show your work! If you give me answers only, I will not give you full credit. Use graphs/Punnett squares, explain your logic, etc.
- Try out several blood types on #6. Using the actual genotypes is very helpful.
- Be aware that on #7 we have 2 traits, so a complete genotype will have 4, not 2 letters for each person. It is called a Dihybrid Cross.
For this weeks lab, you will be using a tool called the virtual genetics lab. Here you will create crosses of experimental animals and try to predict what mode of inheritance your organisms have. This lab requires that you complete 3 crosses in the software, the first one is practice with the answer and two additional experimental crosses in which there is no answer, you must make crosses until you are sure that you have enough evidence to reject or support your hypothesis.
Website needed to download the virtual genetics lab: http://vgl.umb.edu/ (Links to an external site.)
Upload your lab report, including the information from all 3 crosses as your experiment.