Why do multicellular organisms with specialised tissues and organs need more complex methods of reproduction than simple organisms like Spirogyra?
Generated by claude-sonnet-4-6 · 2026-06-26 01:01 · grounding rag
Model Answer
In simple organisms like Spirogyra, cells are not highly specialised, so the organism can simply break into fragments that grow into new individuals.
In multicellular organisms with specialised tissues and organs, cells are organised in a specific pattern. Simple cell-by-cell division would disturb this organisation, making it impractical. Therefore, more complex reproductive methods involving specific reproductive cell types are needed.
Source: Chapter 7, Section 7.2.2
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Explanation
- The key contrast examiners look for: Spirogyra has no specialised tissues (Activity 7.4 confirms this), so fragmentation works.
- For complex multicellular organisms, the textbook explicitly states: "specialised cells are organised as tissues, and tissues into organs placed at definite positions — cell-by-cell division would be impractical."
- Always mention both sides: why simple organisms can use simple methods AND why complex organisms cannot.
- For 2 marks, one point each for the simple and the complex organism is the safest structure.