Which of the following domains contains the most primitive bacteria that live in extreme environments
(a) Archaea
(b) Plantae
(c) Fungi
(d) Eukarya

Options

A. Archaea
B. Plantae
C. Fungi
D. Eukarya

Explanation

To solve the question about which domain contains the most primitive bacteria that live in extreme environments, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Domains of Life**:
- There are three main domains in the classification of life: Archaea, Eubacteria (or Bacteria), and Eukarya.

2. **Identify the Characteristics of Each Domain**:
- **Eubacteria**: This domain includes common bacteria that are found in various environments but are not typically associated with extreme conditions.
- **Archaea**: This domain includes bacteria that are known for living in extreme environments (such as hot springs, salt lakes, and acidic environments). They are considered the most primitive forms of life on Earth.
- **Eukarya**: This domain includes all eukaryotic organisms, such as animals, plants, and fungi, which are not primitive bacteria.

3. **Focus on the Question**:
- The question specifically asks for the domain that contains the most primitive bacteria living in extreme environments.

4. **Analyze the Options**:
- (a) Archaea: Known for extreme environments and primitive characteristics.
- (b) Plantae: Includes plants, not bacteria.
- (c) Fungi: Includes fungi, not bacteria.
- (d) Eukarya: Includes complex organisms, not primitive bacteria.

5. **Select the Correct Answer**:
- Based on the analysis, the correct answer is **(a) Archaea**, as it contains the most primitive bacteria that thrive in extreme environments.

### Final Answer:
**(a) Archaea**

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