How to kill the tree

How is Bt toxin known to kill the target insects in protection of cotton plants?

Complete girdling ultimately kills the tree due to

Removal of bark is generally practiced to kill a tree . The tree actually does not survives after removal of bark because

Why does the Bt toxin not kill the bacterium that produces it but kills the insect that ingests it?

How large is the tree of Ficus developed from that tiny seed?

An observer on the top of a tree ,finds the angle of depression of a car moving towards the tree to be 30^@ .After 3 minutes this angle becomes 60 ^@ .After how much more time , the car will reach the tree ?

Bt toxin kills the insect by

The herbicide DCMU kills the weeds because it inhibits

How does the removal of a ring of bark and wood from the trunk of a tree kills it ?

A monkey is sitting on the tree. A hunter fires a bullet to kill him. At the same time monkey falls downward. Will the bullet strike him?