Genetics Test 2
1. Cystic fibrosis
occurs at a rate of 1 in 10,000. Most
people affected by the disease do not live long enough to reproduce.
What would be the percentage of carriers in the population?
Show all your calculations. 
2. Can a person with
blood type "A" receive a transfusion from a person who is
blood type AB? Use diagrams
to explain. 
3. Name and briefly
describe the common types of genetic mutations. 
4. Simian virus 40
(SV40) has a genome of 3600 bases.
a. What is the maximum number of amino acids it could code
b. If 30 proteins of average length 100 aminos are produced,
what does this tell you in so far as
introns, exons and overlapping genes are concerned? 
5. Name the three types
of RNA. For each, briefly
describe its function. 
6. When DNA is
replicated, one strand is synthesised continuously, one strand is
synthesised discontinuously Why? 
7. Which is the major
enzyme responsible for the following:
a. RNA is transcribed into DNA
b. DNA is transcribed into RNA
c. RNA is translated into protein.
8. Xenopus laevis, the
over-worked "guinea-pig" of research, has two classes of
organism has a total known number of antibodies of 6400.
How many D and V regions might there be on the genome?
Show your work.
(X. laevis is actually a South African horned toad) 
9. What would be a
likely DNA sequence to code for the tri-peptide: ala-phe-glu. Include all relevant codons. 
10. Pepsin is a protease.
It consists of 160 amino acids.
The mRNA for pepsin is 600 bases long.
What conclusions can you reach based on this information? 
11. Why would a researcher
want to clone?
12. For what reason might a
researcher use radioactive mRNA probes?
13. The eighth amino acid in
haemoglobin is supposed to be glutamic acid.
Haemophiliacs do not have glutamic acid in this place.
Which base (first second or third) is likely incorrect in the
haemophiliacs? Why?