UPSC CSE Prelims
Question 68
Consider the following statements :
DNA Barcoding can be a tool to :
- assess the age of a plant or animal.
- distinguish among species that look alike.
- identify undesirable animal or plant materials in processed foods.
Which of the statements given above is/are correct ?
View correct answer and explanation
Correct answer: D
Correct Option: D (2 and 3)
Explanation: DNA barcoding compares short standard DNA sequences to identify species or ingredients; DNA sequence identity alone does not determine the age of an organism.
Statement / Pair / Item-wise Analysis:
1. False / does not qualify - Barcoding identifies taxonomic identity, not an individual plant’s or animal’s chronological age.
2. True / qualifies - Genetic barcodes can distinguish morphologically similar/cryptic species.
3. True / qualifies - DNA markers can detect mislabeled or undesirable biological ingredients in processed food.
Option-wise Analysis:
A. Incorrect-includes 1 even though Barcoding identifies taxonomic identity, not an individual plant’s or animal’s chronological age.; omits 2 even though Genetic barcodes can distinguish morphologically similar/cryptic species.; omits 3 even though DNA markers can detect mislabeled or undesirable biological ingredients in processed food.
B. Incorrect-omits 2 even though Genetic barcodes can distinguish morphologically similar/cryptic species.
C. Incorrect-includes 1 even though Barcoding identifies taxonomic identity, not an individual plant’s or animal’s chronological age.; omits 3 even though DNA markers can detect mislabeled or undesirable biological ingredients in processed food.
D. Correct-selects exactly the correct statements/items identified above.