Transport system of the body made up of the heart, the blood vessels and the blood. Also known as the circulatory system
The system of organs including the nose, mouth, trachea, bronchi, bronchioles and alveoli through which air is taken into the body
The organ system in the body which breaks down large insoluble food molecules into small soluble molecules which can be used by the body
The part of a cell that controls the cell function and contains the chromosomes.
A group of cells in an organism that are specialised to work together to carry out a particular function.
A structure with a particular function which is made up of different tissues.
Deoxyribonucleic acid. This is the molecule which contains the genetic code. It coils up tightly inside chromosomes. DNA is a double helix made from two strands which are joined together by pairs of bases.
Cells are fantastic individual units, but they are even better together! Cells are usually found as part of a tissue, which is when several of the same type of cell are grouped together. An example of this is muscle tissue.
Organs are made up of several different tissues, and so they contain several different types of cell. There are many different organs in our bodies, our hearts, lungs, stomachs etc. Even our skin is an organ!
Organs often come together to form systems, with each system having a very specific role to play in the body. Examples include the cardiovascular system, the respiratory system and the digestive system. Systems come together to form organisms.
See the animation below for a more detailed insight into each step, starting from the body, working all the way down to the DNA inside the cell nucleus.