The bacterium Bacillus tJmringiensis is widely used in contemporary biology as a/an

Options

A. Indicator of water pollution
B. Insecticide
C. Agent for production of dairy products
D. Source of industrial enzyme

Answer

**Step-by-Step Solution:**

1. **Identify the Bacterium**: The question asks about the bacterium Bacillus thuringiensis. It is essential to recognize this bacterium and its characteristics.

2. **Understand Its Function**: Bacillus thuringiensis is known for its ability to produce toxins. These toxins are particularly effective against certain insects that feed on plants.

3. **Mechanism of Action**: The bacterium produces these toxins during a process called sporulation. When insects ingest these toxins, they block the gut of the insects, leading to their death.

4. **Applications in Biology**: Given its ability to kill plant-feeding insects, Bacillus thuringiensis is widely utilized in agriculture and biotechnology as a biological pesticide.

5. **Evaluate the Options**: The question provides four options:
- A) Indicator of water population pollution
- B) Insecticide
- C) Agent for production of dairy products
- D) Source of industrial enzyme

6. **Select the Correct Answer**: Based on the understanding that Bacillus thuringiensis is primarily used as a pesticide to control insect populations, the correct answer is option B: Insecticide.

**Final Answer**: The bacterium Bacillus thuringiensis is widely used in contemporary biology as an insecticide.

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