Waste management and pollution

Limpets are small animals with shells.

Limpets attach to rocks on sea shores.

Figure 9 shows limpets on rocks.

Limpets eat algae.

Limpets are prey for crabs.

Give the food chain for algae, crabs and limpets.

Students estimated the population of limpets on a sea shore.

The students were given a square quadrat.

Figure 10 shows the quadrat.

Calculate the area of the quadrat in m².

The total area of the sea shore was 1800 m².

The students sampled 2% of the total area of the sea shore.

Calculate the number of times the students needed to use the quadrat for the 2% sample.

Use your answer from Question 05.2

Explain why throwing a quadrat is not a random method to estimate population size.

Do not refer to safety in your answer.

Describe one method the students could use to plan where the quadrat should be randomly placed each time.

Suggest one hazard the students should be aware of when collecting data on the sea shore.

Do not refer to throwing quadrats in your answer.

Populations of limpets are monitored to assess the impact of pollution in water.

Suggest one type of pollution in water that may affect the population of limpets.

Limpets are small animals with shells.

Limpets attach to rocks on sea shores.

Figure 1 shows limpets on rocks.

Limpets eat algae.

Limpets are prey for crabs.

Give the food chain for algae, crabs and limpets.

Students estimated the population of limpets on a sea shore.

The students were given a square quadrat.

Figure 2 shows the quadrat.

Calculate the area of the quadrat in m².

The total area of the sea shore was 1800 m².

The students sampled 2% of the total area of the sea shore.

Calculate the number of times the students needed to use the quadrat for the 2% sample.

Use your answer from Question 01.2

Explain why throwing a quadrat is not a random method to estimate population size.

Do not refer to safety in your answer.

Describe one method the students could use to plan where the quadrat should be randomly placed each time.

Suggest one hazard the students should be aware of when collecting data on the sea shore.

Do not refer to throwing quadrats in your answer.

Populations of limpets are monitored to assess the impact of pollution in water.

Suggest one type of pollution in water that may affect the population of limpets.

Figure 1 shows a place where peat is being removed from a peat bog.

Why is peat removed from peat bogs? Tick (✓) one box.

Peat can decay. Name one type of organism that causes decay.

Complete the sentences. Choose answers from the box.

The organisms that cause decay respire. The gas used for respiration is. The gas produced by respiration is.

Peat bogs cover a total area of 3 700 000 km². In 2020, 46% of peat bogs were frozen.

How can the area of peat bogs that were frozen be calculated? Tick (✓) one box.

The percentage of peat bogs that are frozen decreases each year. Suggest why the percentage of peat bogs that are frozen is decreasing.

Which two human activities decrease the area of land available for other animals and plants? Tick (✓) two boxes.

Water pollution is a problem for humans and wildlife. Explain how human activities are polluting rivers, lakes and seas.

Water pollution is a problem for humans and wildlife. Explain how human activities are polluting rivers, lakes and seas.

Scientists investigated the effect of soil nitrate ion concentration on the yield of corn. This is the method used.

1. Corn plants were grown in a large box of soil.

2. The soil nitrate ion concentration in the box was kept at 0 parts per million (ppm).

3. All the corn from each plant in the box was removed and weighed.

4. The mean mass of corn per plant was calculated.

5. Steps 1 to 4 were repeated for boxes containing soil with different concentrations of nitrate ions.

Figure 2 shows the corn plants in the box with a 20 ppm soil nitrate ion concentration.

Give two variables the scientists should have controlled in this investigation.

The scientists carried out a valid investigation. Table 1 shows the scientists’ results.

Complete Figure 3. You should:

• label the y-axis

• use a suitable scale for the y-axis

• plot the data from Table 1

• draw a line of best fit.

Table 1 is repeated below.

Describe the relationship between soil nitrate ion concentration and the mean mass of corn per plant. Use data from Table 1 in your answer.

Farmers add nitrate fertiliser to fields where they grow corn. Nitrate fertilisers are expensive.

Evaluate the economic and environmental implications of adding fertiliser to soil in nitrate ion concentrations ranging from 0 to 50 ppm

Every year scientists have recorded the date when migrating birds arrived at summer breeding grounds in the UK.

The records show that for every 1 C increase in mean global temperature, the birds arrived one day earlier.

What will the birds be competing for when they arrive at their UK breeding grounds?

Tick two boxes.

Birds that arrive early might survive better than birds that arrive later.

Suggest one reason why.

Global temperatures are increasing every year.

This is because of an increase of greenhouse gases in the atmosphere.

Name one greenhouse gas.

Global warming affects the migration of animals.

Give one other effect of global warming.

Which two human activities cause global warming?

Tick two boxes.

Which gas in the atmosphere causes acid rain?

Tick one box.

A class of eight students measured the population of water fleas living at the edge of a large pond.

This is the method each student used.

1. Put some pond water in a white tray.

2. Take a pond net and scoop at the edge of the pond a few times.

3. Empty the pond net into the water in the tray.

4. Count the number of water fleas in the tray.

Figure 6 shows a student working.

The students did not control some variables.

Give two variables the students should have controlled to make this a valid method.

The eight students then used a different method to obtain valid results.

Table 2 shows their results.

Calculate the students’ mean value for the population of water fleas at the edge of the pond.

What was the range of the students’ results?

Suggest one reason why such a wide range of results was found.

The teacher then sampled the centre of the pond eight times.

His mean value was 12 water fleas per 1000 cm³ pond water.

What conclusion can you make about the distribution of water fleas in the pond?

Use the students’ mean value from question 04.2 to compare with the teacher’s mean value.

Scientists counted some different invertebrates living in a pond in 2014 and in 2016

Table 3 shows the results.

Calculate the change in the number of bloodworms between 2014 and 2016

Calculate the number of shrimps in the pond in 2016 as a percentage of the number of shrimps in the pond in 2014

Invertebrate species found in a pond can be used as an indicator of the pollution level.

Table 4 shows which species can survive in different levels of pollution.

What conclusion can you make about the change in the level of pollution in the pond between 2014 and 2016?

Give one reason for your conclusion.

Use the data in Table 3 and Table 4

Water pollution and global warming are two problems that have been caused by the rapid increase of the human population.

Suggest two other problems caused by the rapid increase of the human population.