Edexcel IGCSE Biology · Spec 2.51-2.53
Why Multicellular Organisms Need Transport Systems
Covers explain why diffusion is sufficient for unicellular organisms, Explain why multicellular organisms need transport systems and Recall the substances transported in plant phloem.
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Why Multicellular Organisms Need Transport Systems
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Spec 2.51-2.53
What you need to know
- Explain why diffusion is sufficient for unicellular organisms
- Explain why multicellular organisms need transport systems
- Recall the substances transported in plant phloem
Active recall
Quick check
Answer each question before opening the answer.
Why is diffusion sufficient for many unicellular organisms?
They have a large surface area-to-volume ratio and short diffusion distances
Give two reasons multicellular organisms need transport systems
Small surface area-to-volume ratio, long diffusion distances or high metabolic demand
Which two organic substances are carried in phloem?
Sucrose and amino acids
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