Genetics Help Needed

[dracotheferret]

Here are some genetics problems from my homework that I am having trouble with, (some of these are really wierd). I am a non-science major at college so go easy on me:

The following chart shows the results of different matings between jimsonweed plants that had either purple or white flowers and spiny or smooth pods. Determine the dominant allele for the two traits and indicate the genotypes of the parents for each of the crosses.

Parents Offspring phenotypes
purple white purple white
spiny spiny smooth smooth
a. purple spiny x purple spiny 94 32 28 11
b. purple spiny x purple smooth 40 0 38 0
c. purple spiny x white spiny 34 30 0 0
d. purple spiny x white spiny 89 92 31 27
e. purple smooth x purple smooth 0 0 36 11
f. white spiny x white spiny 0 45 0 16










3. Among native Americans, two types of earwax (cerumen) are seen, dry and sticky. A geneticist studied the inheritance of this trait by observing the types of offspring produced by different kinds of matings. He observed the following numbers.

Parents Number of Offspring
mating pairs Sticky Dry

Sticky x sticky 10 32 6
Sticky x dry 8 21 9
Dry x dry 12 0 42

a. How is earwax type inherited?


b. Why are there no 3:1 or 1:1 ratios in the data shown in the chart?




I know that the charts are unclear, and I can make them clearer if you have problems reading them.

I hope for help before tomorrow.