Activity 1: Color blindness is a sex-linked trait, meaning the genes that cause it are located on the X chromosome. In the model to the right, a purple X represents a chromosome carrying a recessive gene that causes colorblindness, while a black X represents a chromosome carrying a normal gene. (Make sure you join ck12.org to complete this activity.)

Move the red points to the genotype of each child's parents.
Observe the probability of the son or daughter being colorblind.

https://www.ck12.org/assessment/tools/geometry-tool/plix.html?eId=SCI.LSC.335.2&questionId=5772b8619616aa4820c91a26&artifactID=2681601&backUrl=https%3A//www.ck12.org/life-science/Sex-linked-Inheritance-in-Life-Science/%3Freferrer%3Dfeatured_content%26by%3Dck12%26difficulty%3Dall%23interactive

Activity 2: Download the pdf file below and complete the practice problems for sex-linked traits. Submit to teacher when complete. (Be sure to show all work.)

Sex-Linked Practice Problems.pdf

Activity 3: Practice - Click on the link below to answer practice questions. (Make sure you have joined ck12.org to complete this activity.

https://www.ck12.org/assessment/ui/?test/view/practice/life-science/Sex-linked-Inheritance-Practice&referrer=featured_content&ep=https://www.ck12.org/life-science/Sex-linked-Inheritance-in-Life-Science/?referrer=featured_content&by=ck12&difficulty=all#interactive

Activity 4: Watch the video below and answer the questions. Modified from CK12.org

Green Genes

Image: New World monkey Saimiri sciureus, the common squirrel monkey

Monkey See, Monkey Do...But What Do Monkeys See?

What do monkeys see? Well, that's hard to say, but we know what they don't see. Full color! At least many monkeys don't and that gave researchers an idea and hope for colorblind humans.

Monkey See from Day's Edge Productions (Video) http://vimeo.com/43015362

Use the resources below to answer the following questions:

What do cone cells do in the human eye? How many different types of cone cells do humans have? How do the pigments in these cone cells differ from each other?
What causes color blindness in some people? Why are some people more likely to have colorblindness than others?
How does color vision differ between male and female squirrel monkeys? What is the physiological cause of this difference?
How is colorblindness in squirrel monkeys similar to color blindness in humans? How does it differ?
How did scientists deliver the modified virus to the squirrel monkeys? Why was this delivery method important to the success of the procedure? Does this problem exist in all cases of gene therapy?

Resources