The fundamental principles discussed in class and in the textbook will become clearer to you, and you will grasp them more surely, if you carefully think through the following problems, which illustrate the various patterns of inheritance treated in class.  Good luck!

The work on the following problems is due by April 17, 2006.  

1. In chile pepper plants, an allele for an ultra hot taste (H) is dominant over the allele for more mild flavor (h).  Give the genotypic and phenotypic ratios for the results of each of the following crosses:

                                                         (a) Hh    X    hh
                                                         (b) Hh    X    Hh
                                                         (c) Hh    X    HH

2.  In human beings, the allele for brown eyes is dominant (B) over blue eyes (b).  Suppose a blue-eyed man marries a brown-eyed woman whose father was blue-eyed.  What proportion of their children would you predict will have blue eyes?

3.  A brown-eyed man whose father was brown-eyed and whose mother was blue-eyed marries a blue-eyed woman whose father and mother were both brown-eyed.  The couple has a blue-eyed son.  For which of the individuals mentioned can you be sure of the genotypes?  What are their genotypes?  What genotypes are possible for the others?

4.   In velociraptors, assume that 4- inch razor-sharp claws (R) are dominant over dull claws (r).  Suppose a velociraptor with 4- inch razor-sharp claws (heterozygous condition) mates with a dull-clawed raptor who's mother and father had 4- inch razor-sharp claws.  What proportion of the clutch would you predict will have 4- inch razor-sharp claws?  What is your most precise estimate of the number of young from a 100 egg clutch resulting from this mating that would have 4-inch razor-sharp claws?

5.  In watermelons, the alleles for green color and for short shape are dominant over the alleles for striped color and for long shape.  Suppose a plant with long striped fruit is crossed with a plant heterozygous for both these characters.  What phenotypes would this cross produce and in what ratios?

6.  A man is accused in a paternity suit of being the father of a child.  He has type B blood, while the mother has type AB blood.  The child's blood is tested and found to be type O.  The medical technician who is conducting the test, checks and double checks the results, and announces to the court, that there is a major problem.  Could the accused man potentially be the father of the baby?  What's the problem that the med-tech has detected?