Practice Paper 2 (Cambridge International IGCSE Science)

Fig. 1.1 shows an animal cell and a plant cell.

Fig 1.1

Table 1.1 shows the names and functions of some of the structures of the cells labelled in Fig. 1.1.

Fig. 1.2 shows some structures organised in order of increasing size, starting with the smallest size.

Fig. 1.2

Use the words from the list to complete Fig. 1.2.

organ organ system tissue

The data shows the concentrations of sugar and starch in an onion.

The onion is tested with Benedict's solution and iodine solution.

Which set of results is correct?

When an aquatic plant is exposed to light, it produces bubbles of oxygen gas.

Plan an investigation to determine the relationship between light intensity and the volume of oxygen gas produced by the aquatic plant.

You are provided with the apparatus shown in Fig. 2.1.

Fig.2.1

You may use any other common laboratory apparatus in your plan.

In your plan, include:

• any additional apparatus and chemicals that you will use
• a brief description of the method, explaining any safety precautions you will take
• what you will measure
• which variables you will control
• how you will process your results to form a conclusion.

You may include a labelled diagram.

You may include a results table (you are not required to enter any readings in the table).

What is not used to monitor the activity of the heart?

Fig. 3.1 shows a food web:

(i) Identify the producer in Fig. 3.1.

(ii) Place a tick (✓) in each box that describes the puffin in Fig. 3.1.

(iii) Pollution in the ocean can kill squid.

Explain how this may reduce the number of foxes.

(iv) Pollution is one reason why squid may become endangered.

State two other reasons why squid may become endangered.

Decomposers are important organisms in ecosystems.

Complete the description of a decomposer.

A decomposer is an organism that gets its .................. from dead or waste .................. material.

Which label represents a plasmid in this diagram of a bacterium?

Which factor would decrease the rate of diffusion from a plant cell?

You are going to investigate vitamin C in apple juice.

You are provided with half an apple and some apple juice.

In the box, make a large drawing of the cut surface of the apple.

You will test the apple juice using DCPIP.

DCPIP is a dark blue solution that turns colourless when vitamin C is added.

The greater the amount of vitamin C in the apple juice, the fewer the drops of apple juice needed to turn the DCPIP colourless.

(i) Procedure

• Use a pipette to put 4 drops of DCPIP into each of three test-tubes.
• Use a clean pipette to add drops of apple juice to one of the test-tubes until the solution becomes colourless. Count the number of drops as you add them.
• Record the number of drops added. This is experiment 1. Record your results in Table 1.1.
• Repeat with the other two test-tubes (experiment 2 and experiment 3) and record your results in Table 1.1.

Table 1.1

(ii) Calculate the average number of drops of apple juice added for the three experiments.

(iii) Suggest one limitation of using a pipette in this procedure

An aquatic plant is placed in a beaker of water containing hydrogencarbonate indicator and kept in the dark.

Which colour will the hydrogencarbonate indicator be after 24 hours?

Fig. 2.1 shows a section of a plant stem.

(i) Circle the substances transported by the cells labelled Q on Fig. 2.1.

amino acids fatty acids glycerol glucose nitrate ions starch sucrose

(ii) One function of xylem is transport.

State one other function of xylem.

Which factors could a person change to reduce their risk of developing coronary heart disease?

1. diet and exercise
2. stress and smoking
3. genetic predisposition and age

What produces active immunity?

Which reasons explain why deforestation contributes to climate change?

Since the introduction of grey squirrels into the UK, the number of red squirrels has decreased from 3.5 million to about 150 000.

The statements give possible reasons for this decrease.

1. Grey squirrels brought a disease (squirrelpox) which kills red squirrels.
2. Grey squirrels are better at getting food than the red squirrels.
3. Red squirrels are less obvious to predators.

Which statements could explain this decrease in the number of red squirrels?

What is a type of tissue in a living organism?

The diagram shows a root hair cell.

Which type of transport is shown by the arrows in this diagram?

A student investigates vitamin C in apple juice.

The student is provided with half an apple and some apple juice.

Fig. 1.1 shows the cut surface of the apple provided.

Fig. 1.1

In the box, make a large drawing of the cut surface of the apple shown in Fig. 1.1.

The student tests the apple juice using DCPIP.

DCPIP is a dark blue solution that turns colourless when vitamin C is added.

The greater the amount of vitamin C in the apple juice, the fewer the drops of apple juice needed to turn the DCPIP colourless.

Procedure:

The student:

• puts 2.0 cm³ DCPIP into a test-tube
• fills a syringe with 10.0 cm³ of apple juice
• adds apple juice to the DCPIP in the test-tube until the DCPIP turns colourless
• records in Table 1.1 the volume of apple juice remaining in the syringe for experiment 1.

The student repeats the procedure and records the volume of apple juice remaining in the syringe for experiment 2 in Table 1.1.

The student repeats the procedure again for experiment 3.

Fig. 1.2 shows the volume of apple juice remaining in the syringe in experiment 3.

Fig. 1.2

(i) Record in Table 1.1 the volume of apple juice remaining in the syringe in experiment 3.

Table 1.1

(ii) Calculate the volume of apple juice added to the DCPIP in experiment 3.

Record your answer in Table 1.1.

(iii) Calculate the average volume of apple juice added.

(iv) Suggest why the student repeats the experiment.

Plants photosynthesise.

State the balanced symbol equation for photosynthesis.

The heart is the organ that pumps blood around the body.

(i) State the name of an upper chamber of the heart.

(ii) State the type of blood vessel that transports blood to the heart.

(iii) State the function of red blood cells.

White blood cells defend the human body against pathogens.

State one other way the human body defends itself against pathogens.

Which row contains the words that can replace X, Y and Z in the description of a food chain?

Energy from the Sun is transferred as …X… to be stored as …Y… energy in a …Z… .

Biodiversity is the number of different …R… in an area.

Which word replaces R in the sentence?

The actual length of a phorid fly is 5500 μm long.

What is the magnification of this diagram of a phorid fly?

A student investigates photosynthesis using the set-up shown in Fig. 2.1.

Fig. 2.1

The student puts the plants in the same warm room with plenty of light.

After three days, the student uses iodine solution to test a leaf from each plant.

Fig. 2.2 shows the results.

Fig. 2.2

(i) Complete the sentences to explain the results in Fig. 2.2.

The colour of the iodine solution shows that only the leaf from plant X contains .................................................. .

This investigation shows that photosynthesis requires the presence of .................................................. .

(ii) State the name of the green pigment needed for photosynthesis.

Photosynthesis is an enzyme-controlled reaction.

Fig. 2.3 shows the effect of temperature on the rate of photosynthesis for three different plants.

(i) Identify the temperature at which the rate of photosynthesis for plant Q is highest.

(ii) In a desert, temperatures are often higher than 40 °C.

Explain why plant S would not survive in a desert.

Use the word enzyme in your answer.

Heart disease is caused by the blockage of arteries in the heart. Less oxygen is transported to the heart muscle, which causes damage to the heart.

(i) State the name of these blocked arteries.

(ii) State the name of the component of blood that transports oxygen.

Which word best describes a disease-causing organism?

Which label shows the site of aerobic respiration in this diagram of an animal cell?

The actual length of a phorid fly is 5.5 mm.

What is the magnification of this diagram of a phorid fly?

Which word describes an action by an organism that causes a change of position or place?

The diagram shows an uncooked potato being used in an experiment. The skin of the potato was removed as shown.

The experiment was left for a few hours.

Which diagram shows the result?

Fig. 3.2 shows the effect of pH on enzyme activity.

Fig. 3.2

(i) The enzyme in Fig. 3.2 is active in the mouth.

When the enzyme reaches the stomach, the enzyme activity changes.

Explain why the enzyme activity changes.

(ii) Draw a curve on Fig. 3.2 to show the activity of a protease enzyme found in the stomach.

Fig. 3.1 shows part of the human digestive system.

Fig. 3.1

(i) State the function of the part labelled X on Fig. 3.1.

(ii) Complete these sentences about the part labelled Y on Fig. 3.1.

The part labelled Y is the .................................................. .

Part Y releases an enzyme to break down fats and oils. This enzyme is called .................................................. .

Fats and oils are broken down into smaller molecules called .................................................. and ..................................................

The diagram shows a cross-section through a leaf.

What are the functions of the tissue labelled X?

1. transport of amino acids
2. transport of sucrose
3. transport of water
4. support