why do plants have large vacuole

Dear Student,

Plants have single large vacoule as compared to the animals which have many small vacuoles. The main reason behind this fact are as follows:

Storage: Plants form the base of the food chain. They are capable of converting inorganic matter to organic matter. To store these inorganic ions they are provided with the large vacuoles. Moreover, plants can not move from one place to another. So, it is very 
easy for a plant to be able to store extra nutrients when they are around for use later when nutrients may not be available

Growth: Plant cells grow by swelling. They are provided with a rigid cell wall. To make this wall expand, plant cells fill their vacuoles to exert pressure from inside.

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