What is the difference between cells, tissues, organs and organ systems?

You can think of these 4 things as a hierarchy, where each 'element' is a building block for the next level. The smallest 'unit' are cells. There are trillions of cells in your body and these cells together make up what we call tissues. These tissues make up organs (so for example the heart is made up of many tissues). These organs then work together forming organ systems (such as the digestive system, which is made from organs such as the stomachintestines and rectum) to perform a particular function. So as demonstrated below, it is not possible to move up the hierarchy without the 'stage' before being there. So if there are no cells, no tissues, organs or any organ systems can form. cells---->tissues---->organs---->organ systems

CG

Related Biology GCSE answers

All answers ▸

Explain how the use of antibiotics might lead to a resistant strain of bacteria arising.


In the case of cystic fibrosis, two parents don't suffer from the disease but both carry the recessive cystic fibrosis allele. What is the probability that a child of the parents will suffer from cystic fibrosis.


Describe how receptors in the skin function.


Explain why your genes might influence how drugs work in the body. (3)