I am in a second year university genetics class, and am having
difficulty with some of our practice problems, I am also very
interested in genetics but find it very difficult, most of these
problems I have a grasp on but want to confirm my thinking, so if
you have the time and want a bit of challenge or fun then help me
out by solving these:

1. In humans, achondroplastic dwarfism and neurofibromatosis are
both extremely rare dominant conditions. Individuals with dominant
rare traits are usually considered to be heterozygous for the loci
governing the trait. If a couple, where the woman has achondroplasia
and the man has neurofibromatosis, have children, what phenotypes
could be produced in their children and in what expected
proportions? Assume that the traits are independently inherited.

2.The current gardener at Mendel's cloister in Brno tried to
repeat
one of Mendel's pea experiments. She crossed a plant with the
phenotype smooth yellow peas with a plant with the phenotype
wrinkled green peas. She found that there offspring consisted of 123
yellow smooth, 134 yellow wrinkled, 189 green smooth and 212 green
wrinkled peas.
A) Determine the genotypes of parents and offspring.
B) What are the expected proportions of the phenotypes in the
offspring?
C) Use a Chi-square test to determine if the observed number fits
the model you proposed in B).

3. A single nucleotide mutation in the gene which codes for the b-
polypeptide which is part of the hemoglobin molecule, alters a
single amino acid from glutamic acid (Glu) to valine (Val).
a) Which nucleotide has been changed?
b) Is this an example of a frameshift mutation? Explain.
c) Explain how this mutation affects the phenotype of its carrier
both at the molecular and individual level

4. A single nucleotide addition and a single nucleotide deletion
approximately 15 bp apart in the DNA cause a protein change in a
sequence from

-Lys-Ser-Pro-Ser-Leu-Asn-Ala-Ala-Lys

to

-Lys-Val-His-His-Leu-Met-Ala-Ala-Lys

a) What are the old and the new mRNA nucleotide sequences? It
is sufficient if you give example of one new mRNA and one original
mRNA sequence.
b) Which nucleotide has been added and which has been deleted?