UPSC Prelims 2017 Q45: Science & Technology – Biotechnology & Genetics
With reference to agriculture in India, how can the technique of 'genome sequencing', often
seen in the news, be used in the immediate future?
1. Genome sequencing can be used to identify genetic markers for disease resistance and
drought tolerance in various crop plants.
2. This technique helps in reducing the time required to develop new varieties of crop plants.
3. It can be used to decipher the host - pathogen relationships in crops.
Select the correct answer
using the code given below:
- (a) 1 only
- (b) 2 and 3 only
- (c) 1 and 3 only
- (d) 1, 2 and 3
Answer: (d) 1, 2 and 3
Explanation
Genome sequencing in agriculture
Genome sequencing reads the complete DNA sequence of an organism.
| Statement | Verdict | Fact |
|---|---|---|
| 1. It can identify genetic markers for disease resistance and drought tolerance in crop plants | Correct | Sequencing reveals genes and markers linked to useful traits |
| 2. It helps reduce the time required to develop new varieties of crop plants | Correct | Marker-assisted selection picks the right plants early, cutting breeding time |
| 3. It can be used to decipher host-pathogen relationships in crops | Correct | Sequencing both the crop and the pathogen shows how they interact |
Crop genomes sequenced:
| Crop | Year | Note |
|---|---|---|
| Rice | 2005 | International project; India took part |
| Pigeon pea (arhar) | 2011 | Decoded by Indian scientists |
| Wheat | 2018 | Very large and complex genome |
Answer: (d) 1, 2 and 3.
Why each option is right or wrong
- (a) Incorrect. Sequencing also shortens breeding time and reveals host-pathogen links.
- (b) Incorrect. Finding genetic markers for disease resistance is its most direct use.
- (c) Incorrect. It also reduces the time needed to develop new crop varieties.
- (d) CORRECT. Genome sequencing helps with markers, faster breeding and host-pathogen studies.
Key point
Genome sequencing in crops: finds trait markers, speeds up breeding through marker-assisted selection, and explains host-pathogen interactions.
Remember
Sequencing = markers + faster breeding + host-pathogen.
Common mistakes
- Confusing genome sequencing (reading DNA) with genetic modification (changing DNA).
- Thinking sequencing helps only with human medicine.
- Doubting statement 2; marker-assisted selection does cut breeding time.
Exam tip
'Can be used' statements about a broad technology are usually all correct.
Sources
- NCERT Class XII — Biology (Biotechnology and its Applications)
- Indian Council of Agricultural Research — Pigeon pea genome sequencing (2011)