Question

It is necessary to kill pupa by boiling cocoon in water at right time. Why

Answer 1

because it is necessary for producing silk from silkworm

Answer 2

Yes, it is necessary to kill pupa by boiling cocoon in water at the right time because to make a long thread of silk so we need to kill it otherwise pupa grows and breaks the cocoon and we will not get a long thread. Hence it is necessary and we cant avoid it.