Riddle: im a plant and im spiky. what am i? i am a _ _ _ _ _ _.

What is a mechanism by which organisms maintain homeostasis when the level of one substance influences the level of another substance or the activity of an organ.

He had fished in the river since ten years and he was a good fisherman. he know where to found the slim sliver chilwa fish, a big beautiful mahseer and the long moustache singhara. he know where the river was deep but where it is shallow; he knew which baits to use - which fish like worms and which liked gram. edit the above

How many questions do you have to answer to be able to message someone on