Gap-fill exercise

Fill in all the gaps, then press "Check" to check your answers. Use the "Hint" button to get a free letter if an answer is giving you trouble. You can also click on the "[?]" button to get a clue. Note that you will lose points if you ask for hints or clues!

All living things are affected by their .
They adapt to that occur in that environment.
Their numbers depend on the availability of , and the or of other organisms.
Organisms like plants which can make their own food are called .
Organisms which cannot make their own food are called .
Organisms which live on other DEAD organisms are called .
Energy being passed from producers from one consumer to the next forms a food .
Food chains with links in common form a food .
The area where an organism lives is called its .
is when an organism evolves to suit changes in its environment.
occurs when two organisms need the same resource.
occurs when two organisms are of help to each other.
Keeping the natural world as it is is called .
Allowing the wrong materials to enter an ecosystem is causing .