The organisms which cause diseases in plants and animals are called

Options

A. pathogens
B. vectors.
C. insects.
D. worms.

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the term used to describe organisms that cause diseases in plants and animals.

2. **Identifying Key Terms**: The options provided are pathogens, vectors, insects, and worms. We need to analyze each term to find the correct answer.

3. **Defining Pathogens**: Pathogens are microorganisms such as bacteria, viruses, fungi, and parasites that can invade the body of a host (plants or animals) and cause disease.

4. **Understanding Vectors**: Vectors are organisms that do not cause disease themselves but can transmit pathogens from one host to another. Examples include mosquitoes and ticks.

5. **Analyzing Insects and Worms**: While insects and worms can be involved in disease processes, they typically do not cause disease directly without the presence of a pathogen.

6. **Conclusion**: Based on the definitions and roles of the terms, the organisms that directly cause diseases in plants and animals are indeed pathogens.

7. **Final Answer**: Therefore, the correct answer to the question is "pathogens."

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