AQA GCSE Synergy Paper 1: Life and environmental sciences Higher June 2023 question paper 8465/1H

This question is about the blood and the circulatory system.

Figure 1 shows a human heart.

Draw one arrow on Figure 1 to show the movement of the blood between the left atrium and the left ventricle.

Which blood vessel carries blood from the lungs into the heart?

Tick (✓) one box.

A B C D

Which blood vessel is the aorta?

Tick (✓) one box.

A B C D

What structures prevent blood flowing in the wrong direction through the heart?

Heart muscle cells obtain oxygen from the blood.

Which blood vessels exchange oxygen with heart muscle cells?

Tick (✓) one box.

Arteries

Capillaries

Veins

Heart rate is controlled by a group of cells called the pacemaker.

Where is the pacemaker in the heart?

Tick (✓) one box.

Left atrium

Left ventricle

Right atrium

Right ventricle

Carbon monoxide is a toxic gas.

Explain why an increase of carbon monoxide in the air increases heart rate.

A person was exposed to carbon monoxide in the air for 1 hour.

During the hour the person’s heart rate increased from 80 beats per minute to 130 beats per minute.

Calculate the percentage increase in heart rate.

Use the equation:

A species of grass has the binomial name Lolium perenne.

What is the genus of the grass?

Grass leaves look green because of a green pigment found in chloroplasts.

Name the green pigment found in chloroplasts.

Which mineral ion is found in the green pigment in chloroplasts?

Tick (✓) one box.

Magnesium ion

Nitrate ion

Sodium ion

An area of grass changed colour after being covered by a tent.

The colour of the grass changed from green to yellow.

Figure 2 shows the area of green grass and the area of yellow grass.

A student used paper chromatography to investigate the pigments in grass leaves from: the area of green grass the area of yellow grass.

Figure 3 shows the results.

Figure 3

Distance

Start line

Green Yellow grass grass leaves leaves

The student crushed the grass leaves.

Describe a method to separate the pigments in the crushed grass leaves using paper chromatography.

Figure 3 is repeated below.

Figure 3

Distance

Start line

Green Yellow grass grass leaves leaves

Determine the R_f value of the pigment that is found in green grass leaves but not found in yellow grass leaves.

Use the equation:

R = distance moved by pigment distance moved by solvent

Use Figure 3.

There are fewer pigments in the yellow grass leaves than in the green grass leaves.

Suggest one reason why.

Figure 4 shows part of the water cycle.

Name processes A and B shown on Figure 4.

Water that is safe to drink is called potable water.

Give two methods used to sterilise potable water.

Explain why it is more expensive to produce potable water from sea water than from river water.

Waste water must be treated to produce potable water.

Waste water from fields where crops are growing may contain chemicals.

Suggest two types of chemical from fields where crops are growing that must be removed from waste water.

Figure 5 shows a light microscope.

A student was given a prepared slide of cells.

Describe how the microscope in Figure 5 could be used to view the cells with the high power objective lens.

Light microscopes are not used to view viruses.

What are two reasons why electron microscopes are used to view viruses?

Tick (✓) two boxes.

Electron microscopes are expensive to maintain

Electron microscopes can have a magnification of ×1 000 000

Electron microscopes have a high resolving power

Viruses are not living organisms

Viruses are found and are replicated inside living cells

Plant species Q is not resistant to one type of virus.

Explain how the process of natural selection could result in all plants of species Q having resistance to the virus.

Earwax is produced by specialised skin cells in the ear.

Suggest one advantage of producing earwax.

People produce either wet earwax or dry earwax.

The type of earwax people have is determined by one gene.

Define the term ‘gene’.

Scientists studied the type of earwax produced by a large number of parents and their offspring.

Table 1 shows the type of earwax of the parents and the number of offspring with each type of earwax.

The allele for wet earwax is dominant.

Give the evidence from Table 1 that shows the allele for wet earwax is dominant.

Consider the offspring born when one parent has wet earwax and one parent has dry earwax.

Explain the number of offspring with each type of earwax born to these parents.

Assume the parent with wet earwax is heterozygous.

Use Table 1.

You should: draw a Punnett square diagram identify each offspring phenotype explain the number of each type of offspring shown in Table 1.

Use the symbols: E = allele for wet earwax e = allele for dry earwax

Carbon-12 (¹²C) and carbon-14 (¹⁴C) are isotopes of carbon.

Carbon-14 is radioactive.

How are the numbers and type of sub-atomic particles in carbon-14 different from the sub-atomic particles in carbon-12?

Carbon-14 is formed in the atmosphere.

Carbon-14 reacts with oxygen to produce carbon dioxide.

Explain why animal tissues contain carbon-14

Carbon-14 emits beta radiation.

Complete the nuclear equation to show the radioactive decay of carbon-14

Use the periodic table.

In 1991 the frozen remains of a human body were found in a glacier.

The carbon-14 in the body was used to determine the age of the body.

The body was 5400 years old.

Explain why the body tissues had not decayed completely.

The amount of carbon-14 in the body had decreased by 47%.

What is the half-life of carbon-14?

Tick (✓) one box.

< 5400 years = 5400 years > 5400 years

A student made a statement about a sample of a different radioactive substance.

The student stated:

‘If the half-life of the radioactive substance is 30 years, a sample of the substance will not be radioactive after 60 years.’

Explain why the student’s statement is not correct.

Figure 6 shows an electric heater.

This type of heater is filled with a liquid.

The heater contained 5.0 kg of water.

When the heater was switched on, the temperature of the water in the heater increased to 75 °C.

The change in thermal energy of the water was 1260 kJ.

specific heat capacity of water = 4200 J/kg °C

Calculate the starting temperature of the water in the heater.

Use the Physics equations sheet.

An identical heater contains 5.0 kg of oil instead of 5.0 kg of water.

specific heat capacity of oil = 1970 J/kg °C

specific heat capacity of water = 4200 J/kg °C

Explain the difference in the energy needed to cause the same temperature change in the oil and in the water.

Gas heaters may be used to heat gardens.

The gas is stored in a container with a fixed volume.

Figure 7 shows a gas heater.

On a sunny day the burner is not lit.

The temperature of the gas in the container increases.

Explain why the pressure inside the container changes.

Xylem tissue and phloem tissue are found in plants.

Compare the structure and function of xylem tissue and phloem tissue.

A student investigated the effect of surface area to volume ratio on diffusion.

The student used gel cubes with different surface area to volume ratios.

The cubes contained indicator and an alkaline solution. The indicator was pink at the start of the investigation because the cubes were alkaline. As acid diffused into the cubes the indicator changed from pink to colourless. If acid had not diffused to the centre of the cube some of the cube would not have changed colour.

This is the method used.

1. Make a gel containing indicator and an alkaline solution.

2. Cut the gel into a cube with 1 cm long sides.

3. Place the cube in a beaker.

4. Cover the cube with acid.

5. After 5 minutes, remove the cube from the acid.

6. Cut the cube in half.

7. Measure the width of the area inside the cube that did not change colour.

8. Calculate the volume at the centre of the cube that did not change colour.

9. Repeat steps 3 to 8 with cubes of different sizes.

Give two control variables the student should have used.

Do not refer to time in your answer.

The student calculated the percentage of the volume of each cube that had changed colour.

Table 2 shows the results.

Calculate percentage X in Table 2.

The different sized cubes are a model for organisms of different sizes.

Explain why surface area to volume ratio is important to organisms of different sizes.

Give two limitations of using cubes to model diffusion in organisms.