Microbes are useful research tools because:

• A. they cannot be cultured in the laboratory
• B. they require complex and expensive growth conditions
• C. they are always pathogenic to humans
• D. they have simple genetic material that is easy to manipulate

Answer: (D)

Verified step by step guidance

1. Understand the question is asking why microbes are useful research tools, focusing on their characteristics relevant to laboratory research.
2. Evaluate each option by considering common microbiological knowledge: microbes can often be cultured in the lab, so the first option is incorrect.
3. Consider the growth requirements of microbes; many have simple and inexpensive growth conditions, so the second option is not generally true.
4. Recognize that not all microbes are pathogenic; many are harmless or beneficial, so the third option is incorrect.
5. Identify that microbes have relatively simple genetic material, which makes them easy to manipulate genetically, explaining why they are valuable in research.