CAPF AC 2022 Q16: Science & Technology – Biotechnology & Genetics
- (a) Intervarietal
- (b) Interspecific
- (c) Intergenic
- (d) Intragenic
Answer: (d) Intragenic
Explanation
Kinds of hybridization
How to think: hybridization means crossing genetically dissimilar plants.
NCERT lists three kinds of crossing.
The prefix inter means between two different things.
The prefix intra means within the same thing, so there is no crossing of unlike plants.
| Type of crossing | Between |
|---|---|
| Intervarietal | Two varieties of the same species |
| Interspecific | Two species of the same genus |
| Intergeneric | Two different genera |
| Intragenic | Not a crossing; it means within a single gene |
Purpose: to combine good characters such as high yield and disease resistance in one variety.
Another way to add a desired character is to introduce a gene, which gives genetically modified crops.
Answer: (d) Intragenic.
Why each option is right or wrong
- (a) Incorrect. Intervarietal crossing between varieties is the most common kind of hybridization.
- (b) Incorrect. Interspecific crossing between two species is hybridization.
- (c) Incorrect. Crossing between different genera (intergeneric) is hybridization.
- (d) CORRECT. Intragenic means within one gene; it is not a crossing of dissimilar plants.
Key point
NCERT Class IX: hybridization may be intervarietal (between varieties), interspecific (between species of one genus) or intergeneric (between genera). Triticale is an intergeneric hybrid of wheat and rye.
Remember
Hybridization is inter- (between), never intra- (within).
Common mistakes
- Missing the difference between inter (between) and intra (within).
- Thinking crossing between different genera is impossible; triticale is one.
- Missing the word not and marking a real type of hybridization.
Exam tip
Educated guess: three options begin with inter and one with intra. The odd prefix is the answer.
Sources
- NCERT Class IX Science — Improvement in Food Resources (crop variety improvement)
- NCERT Class XII Biology — Strategies for Enhancement in Food Production (plant breeding)