Hammerling's experiments of Acetabularia involved exchanging

Options

A. cytoplasm
B. nucleus
C. rhizoid and stalk
D. gametes

Answer

**Step-by-Step Solution:**

1. **Understanding Acetabularia Structure**: Acetabularia is a genus of green algae that has a unique structure composed of three main parts: the rhizoid (base), the stalk, and the cap. The rhizoid typically contains the nucleus.

2. **Hammerling's Experiment**: In his experiments, Hammerling focused on the relationship between these parts, particularly the genetic control of the cap's development. He performed grafting experiments where he combined parts from different species of Acetabularia.

3. **Grafting Procedure**: Hammerling grafted the stalk of one species of Acetabularia onto the rhizoid of another species. This means that the stalk from one species was attached to the base (rhizoid) of a different species.

4. **Observation of Cap Development**: After the grafting, Hammerling observed that the cap that developed on the grafted cell matched the species of the rhizoid rather than the species of the stalk. This indicated that the genetic information controlling the cap's characteristics was located in the rhizoid (where the nucleus is found) rather than in the stalk.

5. **Conclusion**: The key finding of Hammerling's experiment was that the cap's characteristics were determined by the genetic material in the rhizoid, demonstrating the role of the nucleus in cellular control and inheritance.

**Final Answer**: Hammerling's experiments of Acetabularia involved exchanging the rhizoid and the stalk.

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