Edexcel GCSE Biology Paper 2 Higher June 2025 question paper 1BI0/2H

As bananas ripen, they change colour and taste sweeter.

Figure 1 shows two bunches of bananas.

Unripe bananas contain more starch.

Describe the chemical test for starch.

As bananas ripen the starch is converted to glucose.

Describe how bananas can be tested for the presence of glucose.

A banana with green skin tested positive for starch and negative for glucose.

A banana with yellow skin tested positive for both starch and glucose.

Explain why there was glucose in the yellow banana.

Figure 2 shows a diagram of mucus‑producing goblet cells and ciliated epithelial cells in the airways of the lungs.

(Source: © K.K.T Madhusanka/Shutterstock)

Figure 2

Describe how pathogens are removed from the airways by ciliated epithelial cells.

During a race, athletes respire aerobically and anaerobically.

Figure 3 shows an athlete after a race.

Explain how aerobic respiration provides energy for running.

The rate of respiration of maggots was investigated using the equipment shown in Figure 4.

State the reason why the soda lime is placed in the test tube.

The drop of liquid in Figure 4 is at 20 mm.

The drop of coloured liquid moved at a mean rate of 2 mm per minute.

Draw, on Figure 5, the new position of the bubble after the five minutes.

The investigation was repeated with two maggots.

Explain how the movement of the drop of coloured liquid would be affected if the investigation was repeated using fewer maggots.

State one way this investigation can be improved to obtain more reliable results.

In 2018, all the plants were removed from the soil in a 1000 m² area.

A wall was built around this area to keep people out.

In 2019, three species of plants were recorded growing in this area.

Two of these species were indigenous.

State what is meant by the term ’indigenous’.

Name one piece of equipment that could be used to sample the number of indigenous plants in this area.

The area was surveyed every year and the number of plants of each species (A to H) was estimated.

Figure 6 shows the results.

State the trend shown by the data in Figure 6 for plant species C from 2019 to 2023.

A scientist suggested that the decrease in the number of plants of species B in 2021 was caused by competition from one of the other species of plant.

Which species is most likely to have out-competed species B in 2021?

Explain one way that this species could have out‑competed species B.

Give one way that species H could have moved into the area.

Plants also need water to grow.

Explain how water is absorbed into the plant.

Figure 7 shows a type of bacteria (Lactobacillus acidophilus) that is found in cow’s milk.

The magnification of this image is ×18 000.

Measure the length of the bacterium labelled A.

Use your measurement to calculate the actual length of this bacterium in millimetres.

Give your answer in standard form.

Figure 8 shows the growth rate of two species of bacteria at different pH values.

State a pH that allows the growth of both Lactobacillus acidophilus and S taphylococcus aureus.

Describe the relationship between pH and the growth of Staphylococcus aureus, as shown in Figure 8.

A student investigated the effect of temperature on the decay of milk.

Milk was placed in a beaker in a water bath at 5 °C for 72 hours.

The pH of the milk was measured every 24 hours using a pH probe.

The investigation was repeated at different temperatures.

Figure 9 shows the results of this investigation.

Which is a variable that the student needs to control in this investigation?

Describe the changes in the pH of the milk at 30 °C from 0 hours to 72 hours, as shown in Figure 9.

Calculate the rate of decay of the milk at 20 °C for the 72 hours of this investigation.

Use the equation:

_........ change in pH per hour

A teacher was demonstrating a process to students.

The teacher had a beaker of water and added five drops of food colouring to the beaker.

State the process being demonstrated.

A student asked if different food colourings spread evenly in the same amount of time.

Give two variables that would need to be controlled if the investigation was repeated with different food colourings.

The teacher repeated this process with water at different temperatures. Figure 11 shows the results of this experiment.

Draw a line graph to show the results in Figure 11.

Explain why the time taken decreased.

Figure 12 shows the lower epidermis of a leaf, with a stoma labelled.

(Source: © Quagga Media/Alamy Stock Photo)

Figure 12

State the number of guard cells shown in Figure 12.

State one gas that leaves the stomata and one gas that enters the stomata during daylight.

gas leaving stomata

gas entering stomata

State why the stomata close.

A student wanted to view the cross-section of a leaf on a prepared slide.

Describe how a light microscope would be used to observe this slide.

Sugars are transported from the leaves to the rest of the plant.

Explain how sugars are moved through the plant.

Figure 13 shows the biomass of each population of organisms in a food chain.

Figure 13

Calculate the percentage efficiency of biomass transfer from the aphids to the ladybirds.

Use the equation:

Give your answer to the nearest whole number.

Give two reasons why the biomass of ladybirds is lower than the biomass of aphids in this food chain.

Aphids are a problem for rose growers as they damage the leaves of rose plants.

Explain how ladybirds could be used to reduce the number of aphids.

As human population rises, food security is an increasing problem throughout the world.

Give three factors that reduce the amount of food available for humans throughout the world.

Figure 14 is a diagram of the human heart.

Which chambers of the heart contain only oxygenated blood?

The heart has a valve called the bicuspid valve between chamber Q and chamber R.

Explain the role of this valve.

Explain why heart rate increases during exercise.

Every person has a maximum heart rate.

Figure 15 shows how different types of activity affect a person’s heart rate and the type of respiration they are using during that activity.

A person had a maximum heart rate of 190 beats per minute. Calculate the heart rate of this person when they are jogging.

Give your answer to 3 significant figures.

Erythrocytes (red blood cells) transport oxygen to respiring cells.

Explain how erythrocytes (red blood cells) are adapted to carry and release oxygen.

The menopause occurs when the menstrual cycle stops.

Figure 16 shows the hormone concentrations in the blood before the menopause

Compare and contrast the hormone concentrations before and after the menopause.

Explain the roles of FSH and LH in the menstrual cycle.

*(b) Figure 17 shows the blood glucose concentrations for a person who has type 2 diabetes and a person who does not have type 2 diabetes.

Explain how glucose concentrations are controlled for a person with type 2 diabetes and a person who does not have type 2 diabetes.

Include information from Figure 17 in your answer.

Figure 18 shows a diagram of a nephron in the human kidney.

Which letter indicates the glomerulus?

Which letter indicates the Bowman’s capsule?

Describe the process that occurs in the proximal convoluted tubule (PCT).

State the role of the ureters and the bladder in the urinary system.

ureters

bladder

*(c) Explain how the water content of the blood is regulated when a person has consumed a large volume of water and is now overhydrated.