Which of the following statements is true for virus?

Options

A. They are living
B. They are surrounded by peplomers
C. They replicate inside animal cell only
D. Cauliflower mosaic virus has ssDNA.

Answer

To determine which statement is true for viruses, we will analyze each statement step by step.

### Step 1: Evaluate the first statement
The first statement claims that viruses are living organisms.
- **Analysis**: Viruses exhibit characteristics of living organisms only when they are inside a host cell. Outside a host, they do not carry out metabolic processes and are considered inert or non-living. Therefore, this statement is partially true but misleading since it does not accurately represent the nature of viruses in all conditions.

### Step 2: Evaluate the second statement
The second statement mentions that viruses are surrounded by peplomers.
- **Analysis**: Peplomers are indeed glycoproteins found on the surface of some viruses, contributing to the viral envelope. This envelope is crucial for the virus's ability to infect host cells. This statement is true.

### Step 3: Evaluate the third statement
The third statement claims that viruses replicate only inside animal cells.
- **Analysis**: This is incorrect. Viruses can replicate in a variety of host cells, including plant cells, bacterial cells, and animal cells. Thus, this statement is false.

### Step 4: Evaluate the fourth statement
The fourth statement refers to cauliflower mosaic virus as a single-stranded DNA virus.
- **Analysis**: The cauliflower mosaic virus is actually a double-stranded DNA virus. Therefore, this statement is also false.

### Conclusion
After evaluating all statements, the only true statement regarding viruses is the second one, which discusses the presence of peplomers.

### Final Answer
The correct statement about viruses is the second option: "They are surrounded by peplomers."

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