Which of the following disease is casued by virus ?

Options

A. Tobacco mosaic
B. Late blight of potato
C. Turnip mosaic
D. Both (a) and (b)

Explanation

To determine which of the following diseases is caused by a virus, we can analyze the options provided.

### Step-by-Step Solution:

1. **Identify the Diseases**: We need to look at the diseases mentioned in the question. The two diseases mentioned in the video are Tobacco Mosaic and Turnip Mosaic.

2. **Understand Tobacco Mosaic Virus (TMV)**:
- TMV is a well-known viral disease that affects tobacco plants and other members of the Solanaceae family.
- It causes symptoms such as discoloration of leaves (loss of green color) and molting (curving of leaf surfaces).

3. **Understand Turnip Mosaic Virus**:
- Similar to TMV, Turnip Mosaic Virus is also a viral disease.
- It causes mosaic-like lesions on leaves and also leads to molting of leaves.

4. **Identify the Odd One Out**:
- The question mentions another disease, which is Late Blight of Potato.
- Late Blight is caused by a fungus known as Phytophthora infestans, which belongs to the class Oomycetes.

5. **Conclusion**:
- Since both Tobacco Mosaic and Turnip Mosaic are caused by viruses, and Late Blight of Potato is caused by a fungus, the correct answer to the question is that both Tobacco Mosaic and Turnip Mosaic are viral diseases.

### Final Answer:
The diseases caused by viruses are **Tobacco Mosaic and Turnip Mosaic**.