1.What is a “Dihybrid cross”?
A method that is used to demonstrate a predictable pattern of the inheritance of two traits.
List 2 human diseases that are “sex-linked”
Hemophilia and colorblindness
What is a pedigree
A chart that shows all of the known phenotypes for an organism and its ancestors, most commonly including prevalent diseases in a family, traits in animals, etc.
- How many of the hypothetical “babies” produced in your class were identical?
Zero
- How many alleles control hair color in humans? How many for eye color? What do we call the kind of dominance these traits represent?
3 alleles control hair colore and 2 control eye color.
These traits are called polygenetic.
- What does the 9:3:3:1 ratio refer to?
The 9:3:3:1 is the result of a dihybrid cross between two heterozygous parents.This means that you’re mapping out a cross while observing two alleles. Instead of observing the genotypes, however, you are observing the phenotypes.
- What is the difference between a “gene” and an “allele?”
A gene is a specific section of a chromosome where the base pairs that code for the characteristic are stored whereas an allele is the actual sequence of the base pairs in the section.
- How many alleles are involved in a dihybrid cross? How many genes?
4 alleles and 2 genes
- Which of these is dominant: tongue-rolling, color-blindness, ability to taste PTC, widows’ peak?
tongue-rolling, widows’ peak, PTC tasting
