An ecosystem is a community of living things and the environment they share. The chapter asks you to show who eats whom, how energy moves, how populations are measured, and how organisms relate to each other.
This chapter is part of SPM Biology.
How do the four lessons connect?
Each lesson builds on the feeding relationships in the first.
- Constructing food chains and webs shows who eats whom.
- Explaining energy flow follows the energy along those chains.
- Interpreting population-sampling data teaches you to read counts from a field study.
- Comparing interactions and ecological niches sorts relationships such as predation and symbiosis.
A second set of lessons, ecological evidence and population relationships, deepens the evidence skills.
What does one paddy field show?
In a paddy field, rice plants are eaten by grasshoppers, which are eaten by frogs, which are eaten by snakes. That chain has four organisms, and the arrows point from the food to the eater.
Energy enters the chain through the rice plants, which capture light, and some is lost as heat at each step. Counting frogs in sample squares would estimate the population. A snake and a frog have different roles, which is what the word niche describes.
Who should start where?
If your food chain arrows go the wrong way, begin at lesson one. If you can draw chains but struggle to explain energy, go to lesson two. If sampling calculations confuse you, start at lesson three.
Test yourself with the ecosystems practice set.
When does extra help make sense?
Ecosystems answers win marks through precise wording, such as “energy is lost as heat” rather than “energy is used up”. A teacher who reads your answers can tighten each one.
If that would help, see online one-to-one Biology tuition and mention ecosystems when you enquire.