Which one of the following living phenomena is absent in viruses ?
(a) Mutation
(b) Replication
(c) Production of energy
(d) None of these

Options

A. Mutation
B. Replication
C. Production of energy
D. None of these

Explanation

To solve the question "Which one of the following living phenomena is absent in viruses?" we need to analyze each option provided:

1. **Understanding Viruses**:
- Viruses are considered obligate parasites, meaning they cannot reproduce or carry out metabolic processes without a host cell. They consist of genetic material (either DNA or RNA) surrounded by a protein coat.

2. **Analyzing the Options**:
- **(a) Mutation**:
- Viruses can mutate because they possess genetic material. Mutation is a change in the genetic sequence, which can occur during replication. Therefore, viruses are capable of mutation.
- **(b) Replication**:
- Viruses replicate, but they do so by hijacking the cellular machinery of a host organism. They can replicate using either the lytic or lysogenic cycle. Thus, they are capable of replication.
- **(c) Production of energy**:
- Viruses do not produce or liberate energy. They do not have the cellular machinery to carry out metabolic processes, including energy production. They rely entirely on the host cell for their energy needs.
- **(d) None of these**:
- This option suggests that all the phenomena listed are present in viruses, which is not true since they do not produce energy.

3. **Conclusion**:
- The only phenomenon that is absent in viruses is the production of energy. Therefore, the correct answer is **(c) Production of energy**.

### Final Answer:
(c) Production of energy