Tuesday, March 17, 2009

GENETIC CODE AND PROTEIN SYNTHESIS

1. Anticodons are present on:
A. Coding strand of DNA.
B. mRNA
C. tRNA
D. rRNA

Answer: C. tRNA

2. Codons are present on:
A. Non-coding strand of DNA
B. hnRNA
C. tRNA
D. None of the above

Answer: B. hnRNA

3. Nonsense codons are present on:
A. mRNA
B. tRNA
C. rRNA
D. None of the above

Answer: A. mRNA

4. Genetic code is said to be degenerate because:
A. It can undergo mutation
B. A large proportion of DNA is non-coding
C. One codon can code for more than one amino acids
D. More than one codons can code for the same amino acids

Answer: D. More than one codons can code for the same amino acids

5. All the following statements about genetic code are correct except:
A. It is degenerate
B. In is unambiguous
C. It is nearly universal
D. It is overlapping

Answer: D. It is overlapping

6. All the following statements about nonsense codons are true except:
A. The do not code for amino acids
B. They act as chain termination signals
C. The are identical in nuclear and mitochondrial DNA
D. They have no complementary anticodons

Answer: C. They are identical in nuclear and mitochondrial DNA

7. A polycistronic mRNA can be seen in:
A. Prokaryotes
B. Eukaryotes
C. Mitochondria
D. All of the above

Answer: A. Prokaryotes

8. Non-coding sequences are present in the genes of:
A. Bacteria
B. Viruses
C. Eukaryotes
D. All of the above

Answer: C. Eukaryotes

9. Non-coding sequences in a gene are known as:
A. Cistrons
B. Nonsense codons
C. Introns
D. Exons

Answer: C. Introns

10. Splice sites are present in:
A. Prokaryotic mRNA
B. Eukaryotic mRNA
C. Eukaryotic hnRNA
D. All of the above

Answer: C. Eukaryotic hnRNA

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