AQA GCSE Synergy Paper 2: Life and environmental sciences Higher June 2024 question paper 8465/2H

Two students analysed water from four rivers.

Each student measured the pH of the river water using a different method.

Table 1 shows the results.

Suggest what was used to measure the pH in each method.

Why is it not valid to calculate a mean of the two pH values for each river?

Tick (✓) one box.

A mean cannot be calculated from only two values.

Each method gives values to a different resolution.

The mean should be calculated for each method using all four samples.

Which river is most likely to be in an area with a high concentration of sulfur dioxide in the air?

Use Table 1.

Tick (✓) one box.

W X Y Z

Explain your answer to Question 01.4.

Describe a method to determine the mass of dissolved solids in 50 cm³ of river water.

Biodiversity is the variety of species within an ecosystem.

A student investigated the biodiversity in a field.

In part of the field, the living grass had been replaced with plastic grass.

Other plants grow between living grass plants and between pieces of plastic grass.

Figure 1 shows the field.

Figure 1

Living grass

Plastic grass

The student used quadrats to randomly sample the biodiversity of plants in:

the area with living grass

the area with plastic grass.

Describe how the student could decide where to randomly place the quadrats in the area with plastic grass.

How would a greater number of different plant species affect the biodiversity of animals in the area?

Another student used a transect to place quadrats in the field.

Figure 2 shows the position of the transect.

The student placed a quadrat every 5 metres from point A to point B.

Table 2 shows the results.

Describe the relationship between the type of grass and the number of plant species.

Which of the following are two improvements to the investigation that used a transect?

Tick (✓) two boxes.

Decrease the length of the transect to 20 metres.

Increase the distance between quadrats from 5 metres to 10 metres.

Record the number of plants of each species as well as the number of species.

Repeat three times at different times of the same day.

Repeat using three different transects that cross the two types of grass.

Small pieces of plastic break off plastic grass and enter rivers and oceans.

Leaves from trees take longer to decompose on plastic grass than on living grass.

Other plants can grow between pieces of plastic grass.

Plastic grass cannot be recycled.

Explain how plastic grass affects biodiversity of ecosystems.

Ecosystems with low biodiversity may have small populations of some species.

Why are small populations more likely to become extinct than large populations?

Tick (✓) one box.

A small population may be more varied genetically than a large population.

Large populations in the same habitat interact to form communities.

Less genetic variation is a greater risk if the ecosystem changes.

Suggest two ways biodiversity in and around fields can be increased.

Do not refer to plastic grass.

The electromagnetic spectrum is grouped into different types of wave.

Each type of wave has different uses.

Complete the table.

A student investigated the absorption of infrared radiation by a black surface and by a white surface.

The student painted the bulb of one thermometer black and the bulb of another thermometer white.

Figure 3 shows some of the equipment used.

This is the method used.

1. Ensure that the initial temperature shown on the thermometers is the same.

2. Switch on the infrared heater.

3. Record the temperature shown on each thermometer every 30 seconds for 5 minutes.

Explain why the distance between the infrared heater and each thermometer should be the same.

The infrared heater was a hazard in this investigation.

Describe the risk to the student and one precaution that the student should have taken.

Figure 4 shows the results.

Explain the conclusion that can be made from the results in Figure 4.

The paint used for the thermometer bulb painted white was a matt white paint.

The investigation was repeated using a thermometer bulb painted with shiny silver paint.

The distance between the thermometer and the heater was the same as in the first investigation.

The room temperature was the same as in the first investigation.

Draw a line on Figure 4 to predict the results for a thermometer painted with shiny silver paint.

Carbon monoxide is an atmospheric pollutant.

Carbon monoxide can have dangerous effects on the human body.

Describe how carbon monoxide is formed from hydrocarbon fuels.

Red blood cells contain haemoglobin.

Scientists investigated the effect of breathing in air containing different concentrations of carbon monoxide.

The scientists measured the percentage of haemoglobin molecules attached to oxygen at different concentrations of oxygen in the blood.

The air breathed contained:

no carbon monoxide

a low concentration of carbon monoxide.

Figure 5 shows the results.

A person: breathes in air containing no carbon monoxide

has a concentration of oxygen in the blood of 90 arbitrary units.

What percentage of haemoglobin molecules are attached to oxygen?

Use Figure 5.

The scientists repeated the investigation with air containing a higher concentration of carbon monoxide.

Table 3 shows the results.

Complete Figure 5.

You should:

plot the data from Table 3

draw a line of best fit.

A person breathes in air containing a low concentration of carbon monoxide.

Suggest two symptoms the person might show.

Explain why a high concentration of carbon monoxide in the air causes a person to become seriously ill.

Ionising radiation is dangerous to humans because it causes mutations which can cause cancer.

Which of the following can be mutated by ionising radiation?

Tick (✓) one box.

Atoms

Genes

Red blood cells

A nucleus of uranium-238 (U) emits an alpha particle (He) and decays into thorium-234 (Th).

Complete the nuclear equation to show the decay of a uranium-238 nucleus by emitting an alpha particle.

Rocks from a uranium mine contain uranium and several other radioactive isotopes.

Table 4 shows information about two isotopes in a sample of rock from a uranium mine.

The initial number of nuclei of each isotope in the sample was the same.

Explain the difference in the number of nuclei of each isotope in the sample after 5.0 days.

Your answer should include calculations.

Scientists collected data about lung cancer in the population of one country.

They used the data to predict the number of cases of lung cancer in people who work in uranium mines.

Table 5 shows the predicted number and the actual number of cases.

What was the percentage increase in the actual number of cases compared with the predicted number of cases?

Tick (✓) one box.

185%

440%

540%

Radon is an odourless, colourless gas that builds up in uranium mines.

Radon nuclei emit alpha radiation.

Explain why the actual number of cases of lung cancer in Table 5 is greater than the predicted number.

Figure 6 shows a green pepper growing on a pepper plant.

The cells of the green pepper contain water.

Water cannot enter the cells through the waxy waterproof coating on the outside of the pepper fruit.

Describe how water reaches the green pepper cells.

A pepper cell was viewed using a microscope.

The image of a pepper cell had a width of 32 mm.

The magnification of the image was × 400

Calculate the real width of the cell in micrometres.

Real width = __________________ micrometres

A student investigated how different concentrations of sugar solution affect the mass of pepper tissue.

This is the method used.

1. Cut three pieces of pepper 1 cm wide and 1 cm long.

2. Dry each piece.

3. Record the mass of each piece.

4. Leave each piece in sugar solution for 1 hour.

5. Remove the pieces from the sugar solution and dry each piece.

6. Record the mass of each piece.

7. Repeat steps 1 to 6 using different concentrations of sugar solution.

8. Calculate the mean percentage change in mass at each concentration of sugar solution.

Before the investigation, the pepper was kept at 5 °C.

Suggest why.

Describe why calculating the percentage change in mass is more valid than only calculating the change in mass.

Figure 7 shows the results.

Figure 7

Mean

Concentration

–10

–20

Determine the concentration of the solution inside the pepper cells before the investigation.

_ Concentration = __________________ mol/dm³

Explain the mean percentage change in mass of pepper when the concentration of sugar solution was 0.5 mol/dm³.

As peppers develop, the vacuoles of the cells increase in volume.

Figure 8 shows the shape of a pepper cell before it is fully developed.

Suggest two reasons why the cell walls of pepper cells are wrinkled.

This question is about genetics.

Explain why different genes are made from different lengths of DNA.

Describe why the human population produces approximately 50% female and 50% male babies.

In 2018, a scientist claimed to have genetically modified two human embryos.

Suggest why genetic modification of human embryos is illegal in most countries.

The scientist claimed that the embryos were genetically modified to have a faulty CCR5 gene.

The CCR5 gene codes for a protein that allows HIV to enter cells.

The genetic modification may have caused the embryos to be protected against AIDS.

Suggest how the embryos were genetically modified to make the CCR5 gene faulty.

Suggest what type of cell has the CCR5 protein in its cell membrane.

What type of drug is used to treat HIV?

Funnel-web spiders produce a poison to kill prey.

The poison enters the prey when the spider bites the prey.

The poison contains a protein.

Animals produce protease enzymes.

Explain why protease enzymes do not protect animals that are bitten by funnel-web spiders.

The protein from the poison may be used in a new drug.

The protein allows heart muscle tissue to function in low concentrations of oxygen.

Explain how coronary heart disease can decrease the concentration of oxygen in heart muscle tissue.

The new drug may be useful when transporting a donor heart to a patient for a heart transplant.

Suggest why.

The species of funnel-web spider that produces the poison comes from a small, remote area.

Evaluate the use of the poison from the funnel-web spider as a drug.