What Am I Riddles

Question: Without one or the other both would not exist. what i'm I ?

Question: I live in the dark, I have no heart and I'm just like jelly, if you touch me I'll stung you. What am I

Question: I'm the son of water, but when I return to water, I die. Who am I?

Question: I live with first ones ,they use me well! For the others I am hell! For the third ones I am useless,you can't touch me but you can see me! I am always there within you! Seek for me and and I'm right there! What am I?

Question: Surrounded by green, surrounding white.
Inside is red, holding many black babies.

What is it?