A mutation is a change in the DNA of an organism. The change may or may not result in a change to the physical characteristics (or phenotype) of the organism. Mutations that occur in a gamete (sperm or eggs) can be passed to the next generation, whereas mutations that occur in body (or 'somatic') cells may be harmless or may result in a disease such as cancer. Mutations can result in DNA being copied incorrectly. Mutagens can also cause mutations.
A point mutation is a change in one base in the genetic code. The change of one base to a different base (often caused by the DNA being copied incorrectly)-this is called a substitution mutation.
Match List – I with List – II.
| LIST I | LIST II |
| A. UV-Rays | I. Chemical Mutagen |
| B. Transposons | II. Sickle cell anaemia |
| C. Ethylene oxide | III. Physical Mutagen |
| D. Point mutation | IV. Biological Mutagen |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → A-III, B-IV, C-I, D-II
A. UV-Rays — this matches III. Physical Mutagen. Radiation causes mutations.
B. Transposons — this matches IV. Biological Mutagen. Mobile DNA segments cause mutations when they move.
C. Ethylene oxide — this matches I. Chemical Mutagen. A chemical that alters DNA.
D. Point mutation — this matches II. Sickle cell anaemia. A single base change in the β-globin gene.