Two mating types of a variety of a species of Paramecium are

Options

A. morphologically different and physiologi- cally similar
B. morphologically similar and physiologically different
C. physiologically similar
D. physiologically different.

Answer

To solve the question regarding the mating types of a variety of a species of Paramecium, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question asks about the characteristics of two mating types of a species of Paramecium. We need to determine whether they are morphologically (structurally) different or similar, and whether they are physiologically (functionally) different or similar.

2. **Review the Concepts**:
- **Morphology** refers to the form and structure of organisms.
- **Physiology** refers to the functions and processes of organisms.

3. **Refer to Scientific Findings**: According to research by Forney, there are two types of mating in Paramecium, which are categorized as odd and even mating types.

4. **Analyze the Characteristics**:
- **Morphological Similarity**: The odd and even mating types are similar in morphology, meaning they have similar external structures.
- **Physiological Difference**: However, they are physiologically different, meaning their internal processes and functions vary.

5. **Select the Correct Option**: Based on the analysis, the correct answer is that the two mating types are morphologically similar and physiologically different. This corresponds to option 2.

### Final Answer:
The two mating types of a variety of a species of Paramecium are morphologically similar and physiologically different (Option 2).