Excellent

Animals and what structures they use to exchange gases;
Insect – Trachae
Frog – Skin or Lungs
Fish – Gills
Mammal – Lungs

Cell Theory;
· All living matter is made up of one or more cells
· The chemical reaction of a living organism takes place within cells
· All cells are formed from pre existing cells and these cells contain the hereditary information.

Important Cell Dates;
1665 – Robert Hooke observed a piece of cork with the aid of his microscope. He observed many little boxes in which he named “cells”.
1831 – Robert Brown observed a large body (the ...