Go through the following statements:
I. Viruses are more closely related to chemical matter than to a living organism.
II. Viruses and bacteria are the only infectious agents found in plants and animals
III. All viruses are obligate parasites of cells, the majority do not cause disease.
IV. Viruses cannot be observed using a light microscope
Which one is correct option?

Options

A. I and II are correct
B. II and III are correct
C. II and IV are correct
D. I, III and IV are correct

Answer

To determine which of the statements about viruses is correct, let's analyze each statement step by step:

### Step 1: Analyze Statement I
**Statement I:** Viruses are more closely related to chemical matter than to a living organism.

- **Explanation:** Viruses are indeed considered to be at the edge of living and non-living entities. They are composed of genetic material (DNA or RNA) surrounded by a protein coat, which aligns them more closely with chemical structures than with cellular life forms. Thus, this statement is **true**.

### Step 2: Analyze Statement II
**Statement II:** Viruses and bacteria are the only infectious agents found in plants and animals.

- **Explanation:** This statement is **false**. While viruses and bacteria are common infectious agents, there are other infectious agents such as fungi, protozoa, and prions that can also infect plants and animals.

### Step 3: Analyze Statement III
**Statement III:** All viruses are obligate parasites of cells; the majority do not cause disease.

- **Explanation:** This statement is partially true. It is correct that all viruses are obligate parasites, meaning they can only replicate inside a host cell. However, the claim that the majority do not cause disease is misleading. While many viruses do not cause disease, a significant number do, especially in humans and animals. Therefore, this statement is **partially true but misleading**.

### Step 4: Analyze Statement IV
**Statement IV:** Viruses cannot be observed using a light microscope.

- **Explanation:** This statement is **true**. Viruses are typically too small to be seen with a light microscope; they require an electron microscope for visualization due to their nanometer size.

### Conclusion
Based on the analysis:
- Statement I is true.
- Statement II is false.
- Statement III is partially true but misleading.
- Statement IV is true.

The correct options are **I and IV**.

### Final Answer:
The correct statements are I and IV.

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