The X chromosome is categorized under the C group in the human karyotype. It is classified based on its medium size and submetacentric structure, making it distinct from other groups.
| List I (Enzyme) | List II (Function) |
|---|---|
| (A) Cytochrome oxidase | (I) Electron transport system |
| (B) Topoisomerases | (II) Change linking number |
| (C) Cohesins | (III) DNA Replication |
| (D) PCNA | (IV) Cell cycle |