Exchange & transport in animals

This question is about the transport of substances into and out of organisms.

Glucose moves from an area with a high concentration of glucose to an area with a low concentration of glucose.

Name the process that moves the glucose.

Figure 7 shows a salamander.

The species of salamander shown in Figure 7 does not have lungs.

Gas exchange between the air and the blood of the salamander occurs through the skin.

Humans have lungs for gas exchange.

Figure 8 shows the lungs.

Describe how human lungs are adapted for efficient gas exchange.

Figure 7 shows part of the human breathing system.

Label structures A, B and C on Figure 7.

Choose answers from the box.

Describe one way that lungs are adapted for gas exchange.

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 gel cubes: were pink at the start of the investigation became colourless as acid diffused into the cube.

This is the method used.

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

2. Place the cube in a beaker.

3. Cover the cube with acid.

4. Keep the beaker at 20 °C.

5. Record the time taken for the cube to go colourless.

6. Repeat steps 2 to 5 with cubes of different sizes.

Draw one line from each type of variable to that variable in the investigation.

Table 2 shows the results.

Describe the effect of increasing the size of the cube on the time taken for the cube to go colourless.

What would be an improvement to the investigation?

Tick (✓) one box.

Repeat the method three times and calculate a mean for each size cube.

Repeat the method with 5 cubes all of the same size.

Repeat the method with a different size beaker for each size cube.

This question is about the blood and the circulatory system.

Figure 12 shows a human heart.

Draw one arrow on Figure 12 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 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.

All living organisms are made of cells.

Figure 15 shows two types of cell.

Calculate how many times longer the liver cell is than the bacterial cell.

Compare the structure of cell A with the structure of cell B.

You should include similarities and differences in your answer.

Do not refer to cell size.

In multicellular organisms, cells are organised into tissues.

What is meant by a ‘tissue’?

A scientist investigated the effect of different concentrations of sugar solution on red blood cells.

Figure 16 shows the effect of placing a red blood cell into a sugar solution.

What conclusion can be made from the result in Figure 16 ?

Tick (✓) one box.

The sugar solution was less concentrated than inside the cell.

The sugar solution was the same concentration as inside the cell.

The sugar solution was more concentrated than inside the cell.

A student investigated the effect of different concentrations of sugar solution on the change in mass of plant tissue.

The student used pieces of potato.

Describe a method the student could use to produce valid results.

The student used a valid method.

The student calculated the percentage change in mass of the pieces of potato.

Table 5 shows the results.

Complete Figure 17.

You should:

plot the data from Table 5

draw a line of best fit.

Some of the results have been plotted for you.

Determine the concentration of sugar solution that would cause no change in the mass of a piece of the potato.

Use Figure 17.

Concentration of sugar solution = _________________________ mol/dm³

All living organisms are made of cells.

Figure 1 shows two types of cell.

Calculate how many times longer the liver cell is than the bacterial cell.

Compare the structure of cell A with the structure of cell B.

You should include similarities and differences in your answer.

Do not refer to cell size.

In multicellular organisms, cells are organised into tissues.

What is meant by a ‘tissue’?

A scientist investigated the effect of different concentrations of sugar solution on red blood cells.

Figure 2 shows the effect of placing a red blood cell into a sugar solution.

What conclusion can be made from the result in Figure 2 ?

Tick (✓) one box.

The sugar solution was less concentrated than inside the cell.

The sugar solution was the same concentration as inside the cell.

The sugar solution was more concentrated than inside the cell.

A student investigated the effect of different concentrations of sugar solution on the change in mass of plant tissue.

The student used pieces of potato.

Describe a method the student could use to produce valid results.

The student used a valid method.

The student calculated the percentage change in mass of the pieces of potato.

Table 1 shows the results.

Complete Figure 3.

You should:

plot the data from Table 1

draw a line of best fit.

Some of the results have been plotted for you.

Determine the concentration of sugar solution that would cause no change in the mass of a piece of the potato.

Use Figure 3.

Concentration of sugar solution = _________________________ mol/dm³

The human circulatory system transports blood around the body.

The human circulatory system is made of different structures.

Give the structures in order of size from the largest to the smallest.

Choose answers from the box.

The first one has been completed for you.

Figure 1 shows a heart.

The heart pumps blood from the body to the lungs.

Which route does blood travel through the heart?

Tick (✓) one box.

aorta → left atrium → left ventricle → pulmonary artery

aorta → right atrium → right ventricle → pulmonary artery

vena cava → left atrium → left ventricle → pulmonary artery

vena cava → right atrium → right ventricle → pulmonary artery

Explain why the wall of the left ventricle is thicker than the wall of the right ventricle.

What is the function of structure X shown in Figure 1 ?

The heart contains a group of cells called the pacemaker.

Which part of the heart contains the pacemaker?

Tick (✓) one box.

Left atrium

Left ventricle

Right atrium

Right ventricle

What is the function of the pacemaker?

A person started an exercise training programme to improve their health.

Table 1 shows information about the person’s heart.

Stroke volume is the volume of blood pumped out of the heart each beat.

Cardiac output is the total volume of blood pumped out of the heart each minute.

After the training programme the person’s heart rate had decreased.

Explain the effect the training programme had on the person’s cardiac output.

Use Table 1.

Explain how diet and lifestyle can increase the risk of poor health and non-communicable diseases.

Heart tissue is made of cardiac muscle cells.

Figure 2 shows a cardiac muscle cell.

Cardiac muscle needs to contract and relax continuously.

Cardiac muscle cells contain a large number of the structures labelled A.

Name structure A.

Oxygen moves from the cytoplasm into structure A by the process of diffusion.

Why does the oxygen move by diffusion?

Which change would cause the rate of diffusion of oxygen across an exchange surface to decrease?

Tick (✓) one box.

An increase in the surface area of the exchange surface

An increase in the temperature of the cell

An increase in the thickness of the exchange surface

The cardiac muscle cells in humans can respire aerobically and anaerobically. Aerobic respiration uses oxygen. Anaerobic respiration does not use oxygen.

Compare the processes of aerobic respiration and anaerobic respiration.

Do not refer to oxygen in your answer.

Figure 3 shows a diagram of a human heart.

What is the name of blood vessel X ?

Tick (✓) one box.

Aorta

Pulmonary artery

Pulmonary vein

Vena cava

Give one difference in the composition of the blood in the right ventricle compared with the blood in the left ventricle.

When the walls of the atria and ventricles contract, the pressure increases.

Table 4 shows information about the pressure during one contraction of the heart.

The left ventricle has the highest pressure.

Why does the left ventricle need to have the highest pressure?

What is the most likely maximum pressure in the right atrium?

Use Table 4.

Tick (✓) one box.

< 25 = 25 > 25

Some people have a medical condition called a ‘hole in the heart’.

A ‘hole in the heart’ is a small hole between the right ventricle and the left ventricle.

Some blood flows from the right ventricle to the left ventricle.

Explain why a ‘hole in the heart’ causes a person to feel tired.

This question is about breathing and respiration.

What is the equation for aerobic respiration?

Tick (✓) one box.

Figure 5 shows part of the human breathing system.

Name X and Y shown in Figure 5.

Choose answers from the box.

Structure X has adaptations for efficient gas exchange.

Give one adaptation of structure X.

Figure 6 shows a person using a peak flow meter.

Peak flow is how quickly air can be breathed out of the lungs.

Table 3 shows the peak flow of four students.

Asthma is a condition that causes the muscles in the walls of the airways to contract.

What effect will the contracting muscles have on the size of the airways?

Tick (✓) one box.

Which student in Table 3 is most likely to have asthma?

Tick (✓) one box.

Table 3 shows that each student has a different peak flow.

Suggest two factors that may affect peak flow.

Do not refer to asthma in your answer.

A student measured her breathing rate before exercise and after exercise.

Table 4 shows the results.

Explain the effect of exercise on breathing rate.

This question is about breathing and gas exchange.

Figure 8 shows a person using a peak flow meter.

Peak flow is how quickly air can be breathed out of the lungs.

Table 5 shows the peak flow of a person on two different days.

The person has different peak flow results on Day 1 and Day 2.

Suggest one reason why peak flow was lower on the second day.

Calculate value X for Day 2.

Figure 9 shows part of the lungs.

There are many alveoli in the lungs.

Alveoli provide a large surface area for gas exchange.

Explain how two other adaptations of the alveoli allow efficient gas exchange.

Do not refer to surface area in your answer.