Ecosystems, Year 7: more practice

The rabbit

提示It is the first one in the chain that has to eat to get its energy.

为什么The primary consumer eats the producer. The fox is the secondary consumer because it eats the primary consumer.

The thrush

提示The predator is the hunter.

为什么A predator kills and eats other animals. The snail is the thrush's prey.

3

提示The arrows sit between the organisms, not on them.

为什么Four organisms have three gaps between them, so there are three arrows.

The place where an organism lives

提示It is a location, not a feature of the animal.

为什么A habitat provides the food, water and shelter an organism needs, for example a pond or a hedgerow.

They spread the weight so the camel does not sink into the sand

提示Think about walking on soft ground in ordinary shoes versus snowshoes.

为什么A wide foot spreads the camel's weight over a bigger area, so it sinks less in loose sand.

It reduces the surface area, so less water is lost

提示Think about how much leaf is exposed to the dry air.

为什么Fewer and smaller leaves mean less area for water to evaporate from. The thick stem also stores water.

It insulates them, so they lose less heat

提示Think about how a warm coat works.

为什么Blubber is a layer of fat that reduces heat loss to the cold water. It also acts as an energy store.

A fox

提示Follow the steps one at a time.

为什么At step 1 the answer is 'fur', which sends you to step 2. At step 2 'lives on land' leads to fox.

A spider

提示Count the choices as you go through.

为什么Having legs sends you from 1a to step 2, then eight legs leads to spider.

To identify an unknown organism by answering questions about it

提示It helps you find a name.

为什么A key asks a series of questions, usually with two answers, and each answer narrows the choice until only one organism is left.