Several nematodes parasitise a wide variety of plants and animals including ______ . A nematode Meloidegyne incognitia infects the ______ of tobacco plants and causes a great reduction in yield :

Options

A. human beings, stems
B. human beings, flowers
C. insects , roots
D. human beings, roots

Answer

To answer the question, we need to fill in the blanks regarding nematodes and their impact on tobacco plants. Here’s a step-by-step solution:

### Step-by-Step Solution:

1. **Identify the Organisms**: The question mentions "several nematodes parasitise a wide variety of plants and animals." We need to think of a specific example of a plant or animal that nematodes can infect. A common example is **humans**, as nematodes can also be parasites in humans.

2. **Identify the Specific Nematode**: The nematode mentioned in the question is **Meloidogyne incognita**. This nematode is known to cause significant damage to plants.

3. **Determine the Affected Part of the Plant**: The question asks what part of the tobacco plant is infected by Meloidogyne incognita. This nematode is known to infect the **roots** of the tobacco plant, leading to root-knot disease.

4. **Fill in the Blanks**: Based on the above information, we can fill in the blanks:
- Several nematodes parasitise a wide variety of plants and animals including **humans**.
- A nematode Meloidogyne incognita infects the **roots** of tobacco plants and causes a great reduction in yield.

### Final Answer:
Several nematodes parasitise a wide variety of plants and animals including **humans**. A nematode Meloidogyne incognita infects the **roots** of tobacco plants and causes a great reduction in yield.

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