Class 12 Biology · Chapter 7 · Test 3
Genetic Code and Transcription
39 MCQs
39 questions · 35 min · 39 marks
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Sample questions
The first 5 of 39. Try each one, then tap to see the answer.
Question 1
Degeneracy of genetic code means that:
- AA codon consists of 3 nucleotides
- BMultiple codons can specify the same amino acid
- CSame codon can specify multiple amino acids
- DEach codon is read independently of the adjacent codons
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Answer: B
Degeneracy means more than one codon can code for one amino acid.
Question 2
How many codons are needed to specify five amino acids?
- A3
- B5
- C15
- D30
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Answer: B
Each amino acid needs at least one codon so five are required at minimum.
Question 3
Which of these subunits of RNA polymerase is required to initiate transcription?
- AAlpha (α)
- BSigma (σ)
- COmega (ω)
- DBeta (β)
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Answer: B
The σ subunit recognizes the promoter and initiates synthesis.
Question 4
When and where does the splicing of mRNA occur?
- ABefore transcription in nucleus
- BAfter transcription in nucleus
- CAfter transcription in cytoplasm
- DAfter mRNA attachment with ribosome
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Answer: B
Eukaryotic mRNA is modified in the nucleus before moving to the cytoplasm.
Question 5
What happens in mRNA splicing?
- AIntrons and exons are removed from the gene
- BIntrons and exons are joined together
- CExons are removed and introns are joined together
- DIntrons are removed and exons are joined together
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Answer: D
The mature mRNA consists of exons only.
More tests in Chromosome and DNA
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