Plants are made of plant cells and they make their own food.
Animals are made of animal cells with a nucleus. Animals do not make their own food.
Bacteria are single-celled organisms without a nucleus.
Achaea are single-celled as well, but have a different chemical make-up than bacteria.
Protists are microscopic and are usually found in pond water.
Fungi are decomposers - they absorb energy from dead organisms.