How is the study of plant anatomy useful to us?

How is the process of transpiration useful to plants ?

How useful is the study of Body cavity and coelom, in the classification of animals?

The study of photoelectric effect is useful in understanding :

Kranz anatomy is typical of

Drosophila is used in the study of genetics because

[A] : Susruta is one of the earliest scientists who studied human anatomy [R] : Susruta carried out plastic surgery of human nose and used leeches for preventing man nose and used leeches for preventing clotting of blood in post operative cases.

In which ways genetically modified plants are useful?