One characteristic of life is that living things have different levels of organization
-They have both molecular and cellular organization
- They must have the ability to organize simple substances into complex ones.
- They organize cells at several types of levels, namely:
(a) Tissue- a group of cells that perform a common function
(b) Organ - A group of tissues that perform a common function.
(c) Organ system- a group of organs that perform a common function.
(d) Organism- any complete living thing.