Gene Manipulation Multiple Choice Questions on “Applications of Gene Manipulation”.
1. How many routes are available for the biosynthesis of nucleotides in human beings?
A. 1
B. 2
A. 3
D. 4
Answer: B
Clarification: In mammals, nucleotides are produced via two alternate routes, the de novo and the salvage pathway.
2. What are the basic precursors in the de novo pathway of nucleotide synthesis?
A. Carbohydrate, proteins
B. Sugars, amino acids
A. Sugars, vitamins
D. Minerals, carbohydrates
Answer: B
Clarification: In mammals, nucleotides are produced via two alternate routes, the de novo and the salvage pathway. In the de novo pathway, nucleotides are synthesized from basic precursors such as sugars and amino acids.
3. In the salvage pathway, nucleotides are synthesized by the recycling of __________
A. DNA
B. RNA
A. DNA, RNA
D. Sugars
Answer: C
Clarification: In mammals, nucleotides are produced via two alternate routes, the de novo and the salvage pathway. Salvage pathway recycles nucleotides from DNA and RNA.
4. De novo pathway is exploited for the selection of cells carrying functional HPRT and TK genes.
A. True
B. False
Answer: B
Clarification: If the de novo pathway is blocked, nucleotide synthesis becomes dependent on the salvage pathway, and this can be can be exploited for the selection of cells carrying functional HPRT and TK genes.
5. The drug aminopterin blocks the _________ of two enzymes.
A. Salvage pathway
B. De novo synthesis
A. Expression
D. Recombination
Answer: B
Clarification: The drug aminopterin blocks the de novo synthesis of inosine monophosphate (IMP) and thymidine monophosphate (TMP).
6. What do you understand by the term “co-transformation”?
A. Integration of 2 transgenes
B. Integration of similar transgenes
A. Integration of a group of transgenes
D. Integration of chromosomal DNA
Answer: A
Clarification: The transfection with two physically unlinked DNAs results in co-transformation that is the integration of both the transgenes into the genome.
7. Southern blot hybridization is done for testing the presence of _________ in the selection of transformants.
A. Non-selected DNA
B. Selected plasmid DNA
A. Genomic DNA
D. Selected genomic DNA
Answer: A
Clarification: To obtain co-transformants, cells were transfected with HSV Tk gene and well-defined plasmid DNA. Cells selected on HAT medium are then tested by southern blotting for the presence of non-selected DNA.
8. Incorporation of ribozymes into antisense RNA leads to their __________
A. Activity
B. Temperature change
A. Cleavage
D. Regeneration
Answer: C
Clarification: The incorporation of ribozyme catalytic centers into antisense RNA allows the ribozyme to be particularly targeted and then cleaved and degraded.