Which of the following theories refused Darwin's theory of pangenesis mentioned in the book " On the Variation of Animals and Plants Under Domestication " ?

Options

A. Lamarck 's theory of inheritance of acquired characters
B. Weismann's theory of germplasm
C. Haeckel's recapitulation theory
D. Hugo de Vries' mutation theory

Answer

**Step-by-Step Text Solution:**

1. **Understanding Pangenesis:**
- Pangenesis is a theory proposed by Charles Darwin, which suggests that all body cells produce tiny particles called "gemmules." These gemmules are thought to carry hereditary information and gather in the gonads to form gametes (sperm and eggs).

2. **Identifying the Theories:**
- The question asks which theory refutes Darwin's theory of pangenesis. The options provided include:
- A) Lamarck's theory of inheritance of acquired characteristics
- B) Weismann's theory of germplasm
- C) Haeckel's recapitulation theory
- D) Hugo de Vries' mutation theory

3. **Analyzing Each Theory:**
- **Lamarck's Theory:** This theory focuses on the idea that organisms can pass on traits acquired during their lifetime (use and disuse of organs). It does not directly challenge the concept of gemmules or pangenesis.
- **Weismann's Theory:** This theory posits that hereditary information is only passed through germ cells (gametes) and not somatic cells. This directly contradicts the idea of pangenesis, which suggests that somatic cells contribute to heredity through gemmules.
- **Haeckel's Recapitulation Theory:** This theory deals with the development of embryos and their evolutionary history. It does not refute pangenesis.
- **Hugo de Vries' Mutation Theory:** This theory suggests that new species arise from mutations. It does not directly refute pangenesis.

4. **Conclusion:**
- The theory that refutes Darwin's theory of pangenesis is **Weismann's theory of germplasm** (Option B).

**Final Answer:**
- The correct answer is **B) Weismann's theory of germplasm**.

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