New
New
Multicellular and unicellular organisms
I can explain the differences between multicellular and unicellular organisms.
Lesson 6 of 7
New
New
- Year 7
Multicellular and unicellular organisms
I can explain the differences between multicellular and unicellular organisms.
Lesson details
Key learning points
- Unicellular organisms are made of a single living cell.
- Multicellular organisms are made of more than one cell (sometimes millions), and different cells take on different jobs.
- In multicellular organisms, cells join together to form tissues with specific jobs.
- An organ is a group of tissues working together to do a specific job, and organs work together in an organ system.
- Unicellular organisms have different structures that have adaptations to help them function and stay alive.
Keywords
Unicellular - A unicellular organism is a living thing that is just one cell.
Multicellular - Multicellular organisms are made of lots of different types of cells.
Tissue - A tissue is a group of similar cells in the same place with the same job.
Organ - An organ is made up of a group of different tissues that work together to carry out a specific job.
Adaptation - An adaptation is a feature that helps an organism to function and survive.
Common misconception
There are only two types of cell: plant and animal.
The lesson explores the cells of unicellular organisms and some of their adaptations.
The hierarchical organisation of multicellular organism from cell to organ system is a key concept in biology. Showing videos of living unicellular organisms can help pupils to visualise them (otherwise they may remain an abstract concept).
Teacher tip
Licence
This content is © Oak National Academy Limited (2026), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.All organisms, living or dead, are made up of
All organisms, living or dead, are made up of
Q2.Which of these examples are made up of cells?
Which of these examples are made up of cells?
Water
Q3.Starting with the smallest put these structures in order of size
Starting with the smallest put these structures in order of size
Q4.Cells are too small to view with the unaided eye, a is used to magnify them.
Cells are too small to view with the unaided eye, a is used to magnify them.
Q5.Match these common processes of cells to the correct definition
Match these common processes of cells to the correct definition
Q6.Choose two techniques that should not be used in a scientific line drawing of a cell
Choose two techniques that should not be used in a scientific line drawing of a cell
Continuous lines
Labelling
Assessment exit quiz
6 Questions
Q1.An organism made of one cell is called?
An organism made of one cell is called?
Q2.Choose two correct reasons that a unicellular organism is called living
Choose two correct reasons that a unicellular organism is called living
It can breathe
It can think
Q3.An organism that is made up of lots of cells joined together is called
An organism that is made up of lots of cells joined together is called
Q4.Starting from the smallest put these structures in size order
Starting from the smallest put these structures in size order
Q5.Match the keyword to the correct definition
Match the keyword to the correct definition
Q6.Choose which one of the tissues that would not appear in a stomach
Choose which one of the tissues that would not appear in a stomach
Muscle tissue
Epithelial (lining) tissue
Elastic tissue
