Question

How do plants change their shape?
A. By photosynthesis
B. By changing amount of water
C. By using minerals from the soil
D. All of the above

Answer 1

Hint:Plants retain less than 5% of the water absorbed by roots for cell expansion and plant growth. The remainder passes through plants directly into the atmosphere.

Complete answer:
Plants change their shape by changing the amount of water in them, resulting in swelling or shrinking of the plant cells. Plant cells can change their shape with the help of the cytoskeleton present in the cytoplasm in the stress conditions. They can also change the shape by changing the amount of water in and out of the cell by the process of endosmosis and exosmosis.

Endosmosis : When a cell is placed into a hypotonic solution, the water moves inside a cell and swells. This movement of water inside a cell is referred to as endosmosis. It happens because the solute concentration of the surrounding solution is less than that inside the cytoplasm.

Exosmosis : When a cell is placed into a hypertonic solution, the water moves out of the cell and it becomes flaccid. This movement of water out of the cell is called exosmosis. It happens because the solute concentration of the surrounding solution is higher than that inside the cytoplasm.

Hence, the correct answer is option (B) i.e., By changing the amount of water.

Note:Water is the most limiting abiotic factor to the plant growth. Water is important to plants stems from its central role in growth and photosynthesis and also for the distribution of organic and inorganic molecules. In Spite of this dependence, plants can retain less than 5% of the water absorbed by roots for cell expansion and plant growth. The remaining water passes through plants directly into the atmosphere, a process called as transpiration.