Levels of Organisation
Cells form tissues, organs, organ systems and organisms.
About this topic
Life is organised in levels: organelles form cells, similar cells form tissues, tissues combine into organs, organs work together in organ systems, and systems make up the whole organism. Beyond that come populations, communities, ecosystems and the biosphere.
For example, muscle cells form muscle tissue, which with nervous and connective tissues makes the heart, part of the circulatory system. Specialised cells and division of labour make large complex bodies efficient.
Take the human digestive system. Epithelial cells line the stomach, muscle cells churn it, and glandular cells release acid; together these tissues form the stomach, an organ. The stomach, intestines, liver and pancreas combine into the digestive system, which works with the circulatory system to feed the whole organism. At each level, new abilities emerge that single parts could not show.
This idea helps doctors, since a problem such as diabetes starts with cells in an organ but affects the whole body. Plants follow the same pattern, with leaf tissues forming leaves, then shoots. A common slip is mixing up tissue and organ: a tissue is one type of cell working together, while an organ combines several tissues for one main job.
Key ideas
- Specialised cells
- Tissues combine cells
- Organs combine tissues
Quick check
Use cases: where Levels of Organisation helps
- Homework: review the key idea behind Levels of Organisation before you start a problem set.
- Exam revision: use the quick check to test whether you can recall Levels of Organisation without notes.
- Visual learning: play with the interactive lab to see how Levels of Organisation changes when you adjust its inputs.
- Teaching a friend: explain Levels of Organisation in your own words, then compare your version with the key ideas.
Biology underpins medicine, farming, conservation and biotechnology.
Frequently asked questions
What is Levels of Organisation?
Cells form tissues, organs, organ systems and organisms.
What will I learn in Levels of Organisation?
Specialised cells. Tissues combine cells. Organs combine tissues.
Is Levels of Organisation part of Biology?
Yes. It is one of 150 Biology topics on LearnViz HighSchoolEdu, with 3 key ideas, a live animation and a quick check.
Does the Levels of Organisation lab work on a phone or tablet?
Yes. The animation resizes to fit your screen and supports touch, so you can drag, tap and slide with your finger.
How should I study Levels of Organisation?
Read the summary and key ideas first, play with the interactive lab to see the idea in motion, then answer the quick check. If you get a question wrong, go back to the key idea it tests.
Do I need an account, and is my progress saved?
No account is needed. Marking a topic as learned is saved in your own browser, so it stays on that device and is not sent to a server.