Edexcel IGCSE Biology · Spec 2.1
Levels of Organisation
How organelles, cells, tissues, organs and organ systems build up to a whole organism, with animal and plant examples.
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Levels of Organisation
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Spec 2.1
What you need to know
- List the levels from organelle up to organism
- Give an example of each level
- Put the levels in order of size
Active recall
Quick check
Answer each question before opening the answer.
Put these in order of size: organ, cell, organism, tissue, organ system.
Cell → tissue → organ → organ system → organism.
Define a tissue and an organ.
A tissue is a group of similar cells working together; an organ is a group of different tissues working together to perform a function.
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