Material cycles

Farmers can increase crop yield by controlling the conditions that plants grow in.

Draw one line from each substance to how the substance increases crop yield.

Figure 1 shows a food chain for a farmer’s field.

Figure 1

Which is the secondary consumer in the food chain?

Tick () one box.

Bees are insects that live in hives.

The bees fly in and out of the hives.

Figure 2 shows a crop growing in a field.

The farmer has added bee hives to increase the number of bees in the field.

Increasing the number of bees and other insects increases crop yield.

Which are two ways that increasing the number of insects in an area will increase crop yield?

Tick () two boxes.

Some farmers increase the size of hedgerows between fields where crops grow.

Suggest one reason why.

Peat comes from peat bogs.

Peat can be used to produce garden compost.

Table 1 compares peat compost with a sample of soil.

Young plants have short roots.

Explain one advantage of growing young plants in peat compost instead of in soil.

Peat can also be burnt as fuel.

Figure 3 shows part of the carbon cycle.

Name process A and process B.

Choose answers from the box.

Peat contains carbon compounds.

Explain why burning peat contributes to climate change.

Decay is an important process in the carbon cycle.

Which two types of organism cause decay?

Tick () two boxes.

Deforestation affects the carbon cycle.

Give one use of the land after the land has been cleared by deforestation.

This question is about the cycling of water and carbon in ecosystems.

Which reaction produces water? Tick (✓) one box.

The water cycle provides water for plants and animals on land before the water goes into lakes and seas.

Figure 7 represents the water cycle.

Name the processes 1 to 5 shown on Figure 7.

In 2007 the population of the world was 6 000 000 000 A study found that 4.5% of the population had severe water shortage.

Calculate how many people had severe water shortage. Give your answer in standard form.

Why do more people have severe water shortage now than in 2007? Tick (✓) two boxes.

Leaves on a tree contain carbon compounds. In autumn the leaves fall to the ground.

Microorganisms in the soil recycle carbon from the leaves so that the carbon is used for new plant growth. Explain how.

What is one benefit of fallen leaves for living plants? Tick (✓) one box.

This question is about the cycling of water and carbon in ecosystems.

Which reaction produces water? Tick (✓) one box.

The water cycle provides water for plants and animals on land before the water goes into lakes and seas.

Figure 1 represents the water cycle.

Name the processes 1 to 5 shown on Figure 1.

In 2007 the population of the world was 6 000 000 000 A study found that 4.5% of the population had severe water shortage.

Calculate how many people had severe water shortage. Give your answer in standard form.

Why do more people have severe water shortage now than in 2007? Tick (✓) two boxes.

Leaves on a tree contain carbon compounds. In autumn the leaves fall to the ground.

Microorganisms in the soil recycle carbon from the leaves so that the carbon is used for new plant growth. Explain how.

What is one benefit of fallen leaves for living plants? Tick (✓) one box.

Mineral ions are important chemicals in an ecosystem.

Plants take in nitrate ions dissolved in water. Which part of a plant takes in nitrate ions?

Name two chemicals that are cycled between plants, the soil and the air. Do not refer to nitrogen or nitrates in your answer.

All the chemicals in a plant are recycled when the plant dies. Describe how:

• microorganisms recycle chemicals

• the chemicals are used again by new plants.

There has been a rapid increase in the percentage of carbon dioxide in the atmosphere since 1960.

Carbon dioxide is a greenhouse gas that contributes to global warming.

Name one other greenhouse gas.

Global warming causes climate change.

Give two effects of climate change.

Plants take in carbon dioxide from the atmosphere.

Figure 7 shows part of the carbon cycle.

Describe how carbon from the atmosphere is cycled through living organisms.

There has been a rapid increase in the percentage of carbon dioxide in the atmosphere since 1960.

Carbon dioxide is a greenhouse gas that contributes to global warming. Name one other greenhouse gas.

Global warming causes climate change. Give two effects of climate change.

Question 2 continues on page 10

Plants take in carbon dioxide from the atmosphere. Figure 2 shows part of the carbon cycle.

Describe how carbon from the atmosphere is cycled through living organisms.