Tissure used by Steward et al (1957) to prove celluar totipotency was

Options

A. Pith of root
B. Pith of stem
C. Phloem of root
D. Phloem of stem

Answer

To solve the question regarding the tissue used by Steward et al. in 1957 to prove cellular totipotency, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept of Cellular Totipotency**:
- Cellular totipotency refers to the ability of a single cell to divide and produce all the differentiated cells in an organism, including the extra-embryonic tissues.

2. **Identify the Research Conducted by Steward et al.**:
- The research conducted by Steward and his team in 1957 focused on demonstrating that certain plant cells could regenerate an entire plant.

3. **Recall the Specific Tissue Used in the Experiment**:
- In their experiments, Steward et al. used tissues from the phloem of carrot roots. This was crucial in showing that these cells had the potential to develop into a whole plant.

4. **Analyze the Options Provided**:
- The options given are:
A. Pith of fruit
B. Pith of stem
C. Phloem of fruit
D. Phloem of stem
- Based on the knowledge that Steward used phloem tissue, we need to identify which option corresponds to the correct tissue type.

5. **Select the Correct Answer**:
- The correct answer is **C. Phloem of fruit**. This aligns with the findings of Steward et al. regarding cellular totipotency.

### Final Answer:
The tissue used by Steward et al. (1957) to prove cellular totipotency was **C. Phloem of fruit**.

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