A. They are made of some of the same matter
ex: humans and horses are both mammals. We both of bones and grow up feeding from our mothers milk. We do not have the same dna, we are not autotrophs, and we need different amounts of energy to survive
Lipids don't dissolve in water because of the different polarities. Water is polar and lipids are not polar which is why they don't dissolve. What this means is that they don't bond and don't share electrons and therefore don't mix.
According to google. It is a substance produced by a living organism that acts as a catalyst to bring about a specific biochemical reaction.