This short, targeted simulation is adapted from the full-length “Mendelian Inheritance” simulation.

Did you know that more than 99% of your genes are identical to those found in any other human being on the planet? In this simulation, you will learn about color blindness, the principles of inheritance, and how to draw a pedigree tree. You will draw pedigree trees for eye color and color blindness. Do you think eye color could be related to color blindness?

Learn the principles of inheritance

Begin by reviewing some of the principles of inheritance. You will learn about how genes are passed on from your parents with cells called gametes. Discover the difference between phenotypes and genotypes. Then find out how a genotype can be represented using letters, and how to show if an allele is dominant or recessive. You are then ready to draw a pedigree tree.

Explore eye color in the family

Draw a pedigree tree of eye color in the family. First look at an image showing the eye color of each family member. Then add the eye color for each family member to the pedigree tree. Observe how different eye colors have been passed down through the generations. Can you see a pattern?

Explore color blindness in the family

Draw a pedigree tree of color blindness in the family. First read a description describing who is color blind in the family. Then add this information to the pedigree tree. Once again you can observe how color blindness has been inherited. Compare the two pedigree trees you have made. Does eye color correspond to color blindness?