Which is not a concept of Lamarckism?

Options

A. Rate and survival of orgenisms are different due to variations
B. Environmental pressure produces variations
C. An organ in constant use will grow in size
D. Inheritance of acquired characters

Answer

**Step-by-Step Solution:**

1. **Understanding Lamarckism**: Lamarckism is a theory of evolution proposed by Jean-Baptiste Lamarck. It suggests that organisms can pass on characteristics acquired during their lifetime to their offspring.

2. **Key Concepts of Lamarckism**:
- **Inheritance of Acquired Characteristics**: This concept states that traits acquired or lost during an organism's lifetime can be inherited by its offspring.
- **Use and Disuse**: According to this principle, organs that are used frequently become stronger and larger, while those that are not used diminish in size and function.

3. **Identifying the Concepts**: The question asks for a concept that is NOT part of Lamarckism. The options provided include:
- Rate and survival of organisms are different due to variations.
- Environmental pressure produces variation.
- An organ's constant use will grow in size.
- Inheritance of an acquired character.

4. **Analyzing the Options**:
- The first option (Rate and survival of organisms are different due to variations) implies that variations are a key factor in survival, which is not a concept of Lamarckism.
- The second option (Environmental pressure produces variation) also does not align with Lamarck's ideas, as he did not emphasize environmental pressures leading to variation.
- The third option (An organ's constant use will grow in size) aligns with the use and disuse principle.
- The fourth option (Inheritance of an acquired character) is a core concept of Lamarckism.

5. **Conclusion**: The concept that is NOT part of Lamarckism is "Rate and survival of organisms are different due to variations."

**Final Answer**: Rate and survival of organisms are different due to variations.

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