In plants,transpiration plays an important role in,

In higher plants,water is lost from aerial parts mainly through,

Which one of the following forms of Co₂ has controlling influence on stomatal movement?

The stomata close in water-stressed plants due to accumulation of ABA in,

Loss of water from aerial parts of plants in the form of water vapour is called as,

Guttation occurs through,

Which one of the following processes is sometimes called as necessary evil?