What will happen if Hydra is cut transversely into two halves
(a) Build up the lost part
(b) Tend to reunite
(c) Cut ends heal up
(d) Both halves die

Options

A. Build up the lost part
B. Tend to reunite
C. Cut ends heal up
D. Both halves die.

Answer

To solve the question "What will happen if Hydra is cut transversely into two halves?", we need to analyze the characteristics and abilities of Hydra, particularly its regenerative capabilities.

### Step-by-Step Solution:

1. **Understanding Hydra's Anatomy**:
- Hydra is a simple aquatic organism belonging to the phylum Cnidaria. It has a tubular body with tentacles surrounding its mouth.

2. **Transverse Cutting**:
- When the question states that Hydra is cut transversely, it means that the organism is sliced horizontally into two parts.

3. **Regenerative Ability**:
- Hydra possesses a remarkable ability known as regeneration. This means that if it loses a part of its body, it can regenerate that lost part from the remaining cells.

4. **Morpholaxis**:
- The process of regeneration in Hydra is also referred to as Morpholaxis. This term describes how the organism can reorganize its existing cells to form a new body structure.

5. **Outcome of the Cut**:
- When Hydra is cut transversely, each half has the potential to regenerate into a complete organism. The cells at the cut ends will begin to divide and differentiate to form the missing parts.

6. **Evaluating the Options**:
- (a) Build up the lost part: **Correct**. Each half can regenerate the lost part.
- (b) Tend to reunite: **Incorrect**. The halves do not tend to reunite.
- (c) Cut ends heal up: **Partially correct**, but it does not fully describe the regeneration process.
- (d) Both halves die: **Incorrect**. Both halves can survive and regenerate.

7. **Conclusion**:
- The most accurate answer to the question is (a) Build up the lost part, as Hydra can regenerate the lost body parts after being cut.

### Final Answer:
**(a) Build up the lost part**

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