GN(301) EXAM #2 UPDATED ACTUAL QUESTIONS AND CORRECT ANSWERS

GN(301) EXAM #2 UPDATED ACTUAL QUESTIONS AND
CORRECT ANSWERS

Question:
1. What is a point mutation?
Answer:
a change in a single base pair in DNA

Question:
2. What is a frameshift mutation?
Answer:
mutation that shifts the "reading" frame of the genetic message by inserting or deleting a nucleotide

Question:
3. What is a transition?
Answer:
-purine to purine or pyrimidine to pyrimidine
-ex: A to G, C to T

Question:
4. What is a transversion?
Answer:
-purine to pyrimidine or pyrimidine to purine
-ex: A to C, T to G, etc.

Question:
5. What is a nonsense mutation?
Answer:
when protein formation stops earlier than normal

Question:
6. What is a readthrough mutation?
Answer:
when protein formations extend longer than normal

Question:
7. What type of mutation is responsible for sickle cell disease and Tay Sachs disease?
Answer:
-point mutation, transversion
-the sickle form of the hemoglobin gene is created when an adenine nucleotide is changed to a thymine

Question:
8. What type of mutation is responsible for cystic fibrosis?

, Answer:
-frameshift, nonsense mutation
-lack of functioning chloride channels in cell membrane

Question:
9. What type of mutation is Xeroderma pigmentosum?
Answer:
-frameshift mutation
-due to faulty nucleotide excision repair of pyrimidine dimers

Question:
10. Teratogens
Answer:
agents, such as chemicals and viruses, that can reach the embryo or fetus during prenatal development and
cause harm

Question:
11. Mutagens
Answer:
a chemical or physical agent that interacts with DNA and causes a mutation

Question:
12. Congenital defects are...
Answer:
defects present at birth, aka birth defects

Question:
13. Pyrimidine Dimers can be caused by...
Answer:
are molecular lesions formed from thymine or cytosine bases in DNA

Question:
14. •What are some problems that result if mother uses alcohol, DES, thalidomide or accutane during
pregnancy?
Answer:
-limb deformities
-ear eye, skull, heart, and brain defects
-high incidence of cervical and breast cancer

Question:
15. What is a phenocopy?
Answer:
condition resulting from environmental factors that mimics a genetic condition

Question:
16. Aneuploidy