Prelims 2022

Q. Consider the following statements:

DNA Barcoding can be a tool to:

1. Assess the age of a plant or animal.
2. Distinguish among species that look alike.
3. Identify undesirable animal or plant materials in processed foods.

Which of the statements given above is/are correct?
a) 1 only
b) 3 only
c) 1 and 2
d) 2 and 3
Correct Answer: d) 2 and 3

Question from UPSC Prelims 2022 GS Paper

Explanation : 

DNA Barcoding

DNA barcoding is a method of species identification using a short section of DNA from a specific gene or genes. The concept is based on the fact that there is enough variation in the DNA sequences between different species to allow for identification, much like how a barcode identifies different products in a store.

Does DNA Barcoding Assess the Age of Organisms?

DNA barcoding does not provide information about the age of a plant or animal. The age of an organism is not encoded in the DNA sequences used for barcoding. Therefore, this statement is incorrect.

Identification of Cryptic Species

DNA barcoding is particularly useful for distinguishing between species that look very similar to one another, also known as cryptic species. Morphological identification can be challenging or even impossible in some cases, but DNA barcoding allows for precise identification based on genetic differences. Therefore, this statement is correct.

Detecting Food Fraud and Allergens

DNA barcoding can be used to identify components of processed foods, ensuring that the ingredients are correctly labeled and that no undesirable or mislabeled animal or plant materials are present. This application is particularly important for detecting food fraud, allergens, or the presence of species that are not supposed to be in the food product. Therefore, this statement is correct.

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