Some organisms depend on organisms of other species to survive.
The Table gives information about three of these relationships.
Table
| Organism 1 | Organism 2 | Information |
|---|---|---|
| tapeworm | human | the tapeworm lives in the human intestine and absorbs digested food |
| cleaner fish | larger fish | the cleaner fish eats parasites from the skin of the larger fish |
| flea | dog | the flea lives in the fur of the dog and feeds on its blood |
Name the type of relationship between the tapeworm and the human.
Explain why the relationship between the cleaner fish and the larger fish is mutualism.
Explain how the flea harms the dog.
Nitrogen-fixing bacteria live in nodules on the roots of pea plants. The bacteria provide the pea plants with nitrogen compounds.
Suggest what the bacteria gain from the pea plants.
39 exam-style questions on Edexcel GCSE Biology 9.1 Ecosystems and interdependence, covering 9.1.1 Levels of organisation in ecosystems, 9.1.2 Abiotic and biotic factors, 9.1.3 Importance of interdependence, 9.1.4 Parasitism and mutualism, and 9.1.5 Determining number of organisms in an area. Each one has a worked solution and a mark scheme showing where the marks go.