Levels of Organisation

Question 1

Cells

Answer 1

• The lowest structural level
• The smallest structural and functional unit of an organism
• Are specialised to carry out different functions
• E.g. muscle cells are able to shorten in length
• E.g. red blood cells are able to transport oxygen

Question 2

Tissues

Answer 2

• Group of Cells with similar specialisations that carry out a common function are grouped together into tissues.
• E.g. groups of muscle cells make up muscle tissue
• E.g. groups of nerve cells make up nervous tissue

Question 3

Organ

Answer 3

• Different types of tissues work together as organs
• Normally made up of two or more tissues working together
• E.g. the stomach is an organ with epithelial tissue on the inside and muscle tissue in the wall.

Question 4

Organ System

Answer 4

• The highest level of organisation
• A group of organs that work together for a common purpose
• E.g. the respiratory system supplies oxygen and removes carbon dioxide from the blood. The organs include the lungs, diaphragm, intercostal muscles, ribs, trachea, larynx and nose.

Question 5

Cell Theory

Answer 5

The Cell Theory is a basic principle of biology
It has three principles
All living organisms are composed of one or more cells.
The cell is the basic unit of structure and organisation in organisms.
Cells arise from pre-existing cells.