Consider statements about genetics: 1. A codon consists of three nucleotides. 2. The start codon is AUG. 3. Introns are coding sequences. Which are correct? MCQ with Answer and Explanation

Consider statements about genetics: 1. A codon consists of three nucleotides. 2. The start codon is AUG. 3. Introns are coding sequences. Which are correct?
A. 1 and 2 only
B. 1 and 3 only
C. 1, 2 and 3
D. 2 and 3 only
Answer: Option A
Solution (By JKSSB Mock Tests)
The genetic code is read in triplets of nucleotides called codons, each specifying an amino acid. AUG is the universal start codon, which also codes for methionine. In eukaryotic genes, introns are non-coding intervening sequences that are spliced out, while exons are the coding sequences that remain in the mature mRNA. Thus, statements 1 and 2 are correct.

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The vitamin that functions as an antioxidant and is required for the synthesis of collagen is:
A. Vitamin K
B. Vitamin D
C. Vitamin A
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Correct Answer: Option D


Explanation:
Vitamin C (ascorbic acid) is a water-soluble antioxidant that also acts as a cofactor for enzymes involved in collagen synthesis, carnitine synthesis, and neurotransmitter production. Deficiency causes scurvy. Vitamin A is for vision, D for bone, K for clotting. Smokers require higher vitamin C intake due to oxidative stress.

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Correct Answer: Option C


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The cerebellum is a highly folded structure located at the back of the brain, below the cerebrum. It is primarily responsible for coordinating voluntary movements, maintaining balance, posture, and equilibrium. Damage to the cerebellum results in ataxia (lack of muscle coordination). The medulla controls vital involuntary functions like breathing and heart rate.

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Question #3
Consider statements about human diseases: 1. Typhoid is caused by a bacterium. 2. Malaria is caused by a protozoan. 3. Dengue is caused by a virus. Which are correct?
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Correct Answer: Option B


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