Cell wall.
Made of cellulose and acts as a stronger cell membrane in a plant cell
All the members of a specific species that live in an area are a population.
Democritus is a Greek theorist that believes that atom is the smallest part of the substance. Atom, as he defined, is an indivisible entity. Leuccipus was Democritus' teacher who also believed on that notion. All matter are made up of atoms. If atoms are intact, the property of the substance is firm and solid while if the atoms are much apart, it would be described as a gas. Aristotle had a different belief of matter. He believed that the composing entities of matter are the four elements. However, this notion was rejected and proven through scientific inquiries about atoms and subatomic particles