Q.58 Following diagram represents the sequence of genes in a normal chromosome of a plant species:
G H I J ○ K L M N
Match the CORRECT combination for chromosomal mutation using Column I
and Column II.
Column I
P. G H I K L ○ J M N
Q. G J ○ K L H I M N
R. G H I J ○ K L K L M N
S. G H J ○ K L M N
Column II
1. Tandem duplication
2. Deletion
3. Pericentric inversion
4. Non-reciprocal translocation
Step-by-Step Analysis of Column I
P. G H I K L ○ J M N
Gene J has moved from its original position without reversal or duplication.
This represents a non-reciprocal translocation.
P → 4
Q. G J ○ K L H I M N
The gene order including the centromere is reversed.
This is a classic case of pericentric inversion.
Q → 3
R. G H I J ○ K L K L M N
The segment K–L is repeated adjacent to its original position.
This indicates a tandem duplication.
R → 1
S. G H J ○ K L M N
Gene I is missing from the sequence.
Loss of a gene segment corresponds to a deletion.
S → 2
Correct Matching Summary
| Chromosome | Mutation Type |
|---|---|
| P | 4 – Non-reciprocal translocation |
| Q | 3 – Pericentric inversion |
| R | 1 – Tandem duplication |
| S | 2 – Deletion |
Final Answer
The correct combination is:
P-4, Q-3, R-1, S-2
Correct option: (D)
Conclusion
By comparing the altered gene sequences with the normal chromosome and observing
gene loss, duplication, inversion across the centromere, or relocation,
the chromosomal mutations can be correctly identified.
Option (D) accurately matches all gene arrangements with their corresponding
mutation types.
