Flowers cut under water remain fresh for a long time because :

Options

A. they have sufficient supply of water
B. they transpire very rapidly
C. there is no vascular supply to the leaf
D. water column is not blocked by air bubbles

Answer

**Step-by-Step Solution:**

1. **Understanding the Context:** When flowers are cut from their plants, they lose their source of water and nutrients. To keep them fresh for a longer time, it is important to provide them with a continuous supply of water.

2. **Cutting Underwater:** Cutting flowers underwater helps prevent air from entering the stem. If air enters, it can form air bubbles that block the water-conducting vessels (xylem) in the stem.

3. **Absorption of Water:** Once the flowers are cut and placed in water, the stem can continue to absorb water through the cut end. This is crucial for maintaining turgor pressure in the cells, which keeps the flowers looking fresh.

4. **Avoiding Bacterial Growth:** Keeping the cut flowers submerged in water also helps minimize the risk of bacterial growth at the cut surface. Bacteria can clog the xylem vessels, further hindering water uptake.

5. **Conclusion:** Therefore, the main reason flowers cut under water remain fresh for a long time is that the water column in the stem is not blocked by air bubbles, allowing for uninterrupted water absorption.

**Final Answer:** Flowers cut under water remain fresh for a long time because the water column is not blocked by air bubbles.

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