Human impact & biodiversity

The diagram shows the carbon cycle.

Complete the two labels in the diagram to identify the processes involved in the carbon cycle.

Explain the role of decomposers in the carbon cycle.

Decomposition can take place aerobically or anaerobically.

What is meant by the term anaerobically ?

Human activity has led to rising carbon dioxide levels in the atmosphere.

This contributes to global warming and reduces global biodiversity.

Describe two ways in which human activity can reduce local biodiversity.

Gardeners are changing the way they care for their gardens.

Which change would increase biodiversity?

A Adding chemical fertilisers to a grass lawn

B Cutting a grass lawn more often than usual

C Removing a grass lawn area and putting down paving stones

D Replacing a grass lawn area with a wild flower meadow

Gardeners are changing the way they care for their garden.

Which change would increase biodiversity?

A Adding chemical fertilisers to a grass lawn

B Cutting a grass lawn more often than usual

C Removing a grass lawn area and putting down paving stones

D Replacing a grass lawn area with a wild flower meadow

Dodo

The dodo lived in the forests on the island of Mauritius.

They evolved from a much smaller pigeon that flew to the island.

Pigeons escape predators by flying away; they nest in trees so predators find it harder to eat their eggs.

There were originally no predators or humans on Mauritius.

Dodos nested on the ground and did not fly.

Humans arrived on the island in 1598. They brought with them animals that spread across the island destroying forests and eating eggs.

The dodo became extinct by 1700.

Pigeon similar to ancestor of dodo
Dodo

* Explain how the dodo evolved to become a flightless bird and how the arrival of humans resulted in its extinction.

Suggest one way scientists could find evidence that the pigeon and the dodo have a common ancestor.

Which is a positive impact of humans on the environment?

A Building roads and houses on protected land.

B Cutting down forests to plant crops.

C Hunting endangered species.

D Stopping the use of plastic drinking straws.

The diagram shows a killer whale and three species thought to be ancestors of the killer

Species A
Species B
Species C

Killer whales evolved from ancestors that walked on land and then went back into the sea.

Complete the table to show the time when each species A, B and C existed on this

Species A, B and C have not existed on this planet for millions of years.

What have scientists used to provide evidence for the evolution of the killer whale?

*(b) Many tour companies offer whale watching sight-seeing trips when visiting Monterey in California. Read the article about whale watching trips.

One of the best things to do in Monterey is to join one of the whale watching trips offered year-round in Monterey Bay.

These trips allow the thousands of tourists that visit our area to see the spectacular diversity and large numbers of whales, dolphins and other wildlife.

Marine biologist guides will accompany the trips. They provide information for the tourists and collect valuable data on the marine mammals that are sighted.

The boats used are old whaling boats driven by diesel engines. Their original purpose was to hunt the whales for food but the hunting is now banned in Monterey Bay.

Explain how whale watching activities impact on biodiversity in Monterey Bay.

Your answer should include:

• benefits and challenges to maintaining biodiversity

• a judgement about the effect whale watching has on marine life.

What is the independent variable in this investigation?

Put a tick (✓) in the correct box.

Write down two changes that would improve the accuracy of these acid rainwater measurements.

Acid rain forms due to the emission of sulfur dioxide and nitrogen oxides when fossil fuels are burnt. These gases react with water, oxygen and other chemicals in the atmosphere.

The science club used sulfuric acid to represent acid rain.

Suggest why this is not a true representation of acid rain.

Suggest how the investigation could be developed to better represent acid rain.

This is a graph of the results, produced using computer software.

Estimate the range of acidity that by day 14 causes the sunflower plants to be reduced in height by about 50% compared to the sunflower plants in pot A.

Put a tick (✓) in the correct box.

Describe the impact of acid rain on biomass production.

Which statement describes a positive human interaction on an ecosystem?

A Drilling for oil under the North Sea.

B Growing one type of crop in a large area of land.

C Removing peat from bogs for fuel.

D Replanting hedgerows around fields.

Water is cycled in nature.

Name one abiotic factor that affects water uptake by a plant.

Look at the diagram of the carbon cycle.

Which process is shown by arrow X in the diagram above?

Tick (✓) one box.

Which process releases carbon when organisms die ?

Tick (✓) one box.

The graph shows how carbon dioxide levels in the atmosphere have changed during the last 160 000 years.

Read this statement:

Carbon dioxide levels in the atmosphere are rising out of control.

What evidence is there in the graph for and against this statement?

Look at the section of the graph for the last 20 000 years.

What conclusions can be made about the release of carbon dioxide into the atmosphere and also its removal from the atmosphere during the last 20 000 years?

Describe how human activity has contributed to the trends in the graph and suggest how this activity could affect biodiversity.

The information in the box is part of a scientific journal report.

Growing crops with shiny leaves could cause an annual global cooling of over 0.1 °C.

This is almost 20% of the total global temperature increase since the Industrial Revolution.

Most crop plants have non-shiny leaves.

A few varieties of crop plants do have shiny leaves but they do not all produce high yields.

Explain how scientists could use selective breeding to help reduce global temperatures.

Look at the effects of mercury waste from a factory.

The fishermen became ill.

What is the most likely explanation for this?

A Mercury builds up in the food chain.

B Mercury in the seawater gets onto their hands.

C Mercury kills their food supply.

D They breathe in mercury vapour fishing near the factory.

Water is cycled in nature.

Name one abiotic factor that affects water uptake by a plant.

Look at the diagram of the carbon cycle.

Which process is shown by arrow X in the diagram?

Tick (✓) one box.

Which process releases carbon when organisms die ?

Tick (✓) one box.

The graph shows how carbon dioxide levels in the atmosphere have changed during the last 160 000 years.

Read this statement:

Carbon dioxide levels in the atmosphere are rising out of control.

What evidence is there in the graph for and against this statement?

Look at the section of the graph for the last 20 000 years.

What conclusion can be made about the release of carbon dioxide into the atmosphere and also its removal from the atmosphere during the last 20 000 years?

Describe how human activity has contributed to the trends in the graph and suggest how this activity could affect biodiversity.

The information in the box is part of a scientific journal report.

Growing crops with shiny leaves could cause an annual global cooling of over 0.1 °C.

This is almost 20% of the total global temperature increase since the Industrial Revolution.

Most crop plants have non-shiny leaves.

A few varieties of crop plants do have shiny leaves but they do not all produce high yields.

Explain how scientists could use selective breeding to help reduce global temperatures.

Farmers use fertilisers to improve crop yields.

The graph shows how the mass of one fertiliser affects maize yield.

Mass of fertiliser used (per hectare / kg)

What mass of fertiliser would you recommend to produce the best yield?

Explain your answer.

The fertiliser contains high amounts of nitrogen.

Describe one negative effect using fertiliser might have on the environment.