Is the classification system of domains and kingdoms the only system that scientists have ever used to classify organisms?

According to the law of conservation of energy, energy can neither be created nor destroyed. if this is true, why is there less energy in the top of the energy pyramid than there is in the bottom of the energy pyramid?

Which worm has eyespots that are used to detect light? a fluke b marine worm c planarian d tapeworm

Kinases add - groups to other enzymes. this activities some enzyme while inhibiting other