Respiration

This question is about respiration.

Yeast is a type of fungus.

A student investigated how temperature affects respiration in yeast.

Figure 9 shows some of the apparatus used.

The yeast produces a gas. The gas passes through the layer of oil and is collected in the measuring cylinder.

The oil above the yeast and sugar solution prevents oxygen from entering the solution.

What type of respiration occurs in the yeast when no oxygen is present?

This is the method used.

1. Place yeast and sugar solution in a test tube.

2. Add a thin layer of oil.

3. Place the test tube in a water bath at 5 ° C

4. After 10 minutes set up the apparatus as shown in Figure 9.

5. Record the volume of gas collected in 1 hour.

6. Repeat steps 1 to 5 at different temperatures.

Give two control variables the student used in the investigation.

Table 3 shows the results.

Why should the data from Table 3 be presented as a line graph and not as a bar chart?

Tick (✓) one box.

Bar charts are too simple

Temperature is a continuous variable

Volume of gas is a categoric variable

Complete Figure 10.

You should: label the y-axis plot the data from Table 3 draw a line of best fit.

Predict the volume of gas that would be produced at 7 °C.

Use Figure 10.

The student repeated the investigation at 60 °C.

Suggest why gas was not produced by the yeast at 60 °C.

Bees feed on sugar solution produced by the flowers of plants.

Figure 1 shows a bee feeding on a flower.

Why do bees feed on sugar solution?

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For gaseous exchange

To obtain energy

To provide proteins

Bees have a simple nervous system.

The bee nervous system has many similar features to the human nervous system.

The antenna is a sense organ.

The antenna contains specialised cells that detect stimuli.

What are cells that detect stimuli called?

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Coordinators

Effectors

Receptors

When an antenna of a bee touches sugar solution the bee automatically sticks out its tongue.

What type of action is automatic?

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A conscious action

A delayed action

A reflex action

Figure 2 shows the nervous pathway taken when a bee antenna touches sugar solution.

What is the gap labelled X ?

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A gland

A synapse

An impulse

What type of neurone is Y ?

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Motor neurone

Relay neurone

Sensory neurone

Eyes are sense organs that can detect electromagnetic radiation.

A bee’s eye can detect ultraviolet radiation.

Detecting ultraviolet radiation allows the bee to see the parts of the flower that produce sugar solution.

Why is it an advantage for bees to see the parts of the flower that produce sugar solution?

Figure 3 shows the electromagnetic spectrum.

Which letter shows the position of ultraviolet radiation in the electromagnetic spectrum?

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Which part of the electromagnetic spectrum in Figure 3 has the lowest frequency?

In managed forests:

tree seedlings are regularly planted

some trees are regularly removed.

Some of the young trees in a managed forest are removed every year.

The biomass of wood produced by the remaining trees in the forest is increased by removing the young trees.

Explain why.

Explain how the processes of photosynthesis and respiration in a tree are involved in the production of new biomass for the tree.

Planting trees to maintain forests is good for the environment.

Explain the environmental and biological benefits of maintaining forests.

There are many different types of cell in the human body.

Each type of body cell is specialised for a different function.

Draw one line from each type of cell to the function of that cell.

Figure 1 shows a doctor testing a reflex action of a patient.

When the doctor touches the patient’s foot with a blunt rod, the patient’s toes curl.

Where are the receptors in this reflex action?

Tick (✓) one box.

In the brain

In the foot

In the leg

What is the coordinator in this reflex action?

Tick (✓) one box.

The blunt rod

The central nervous system

The sensory neurone

What is the response in this reflex action?

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Feeling the blunt rod

The blunt rod touching the skin

The toes curling

Muscle cells use oxygen for respiration.

Explain why muscle cells need to respire.

It is important to keep our feet healthy.

Figure 9 shows a doctor testing a reflex action of a patient.

When the doctor touches the patient’s foot with a blunt rod, the patient’s toes curl.

Describe the pathway of this reflex action.

Sometimes runners tie their shoelaces too tightly.

Tight shoes can cause muscle pain part-way through a long run.

Explain why the muscle pain starts part-way through the run.

Two students investigated the effect of exercise on breathing rate.

Breathing rate was measured by counting the number of times a student breathed in during 1 minute.

This is the method used.

1. Measure the breathing rate at rest before exercise.

2. Run on the spot for 5 minutes.

3. Measure the breathing rate every minute during exercise.

4. Measure the breathing rate every minute after exercise for 10 minutes.

The students had different breathing rates at rest.

Suggest two factors that could cause the students’ breathing rates at rest to be different.

Suggest one reason why the measurements for breathing rate may not be accurate.

Figure 7 shows the results.

What time did the students start exercising?

Use Figure 7.

Time exercise started = _________________ minutes

Describe two differences between the results of student X and of student Y.

Use Figure 7.

Why does breathing rate change during exercise?

Tick (✓) one box.

To increase the uptake of carbon dioxide and oxygen from the air

To increase the uptake of carbon dioxide from the air

To increase the uptake of oxygen from the air

The breathing rate of the students stayed high after the exercise stopped.

Why does breathing rate stay high after exercise has stopped?

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To break down amino acids

To break down fatty acids

To break down lactic acid

Give one other change that happens in the body during exercise.

Do not refer to breathing rate.

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.

Algal cells can photosynthesise.

A student investigated the effect of light intensity on photosynthesis in algal cells.

Figure 8 shows the apparatus used.

Describe the relationship between light intensity and distance, as the distance of the algal cells from the lamp is doubled.

You must include calculations of light intensity at 20 cm and 40 cm in your answer.

Use the equation:

The student recorded the pH of the water at the start and after one hour in each beaker.

Table 7 shows the results.

The method produced valid results.

Carbon dioxide is an acidic gas.

Explain the results in Table 7.

Corals are animals that live in the sea.

Corals: cannot move from one place to another place feed on tiny animals that float past in the water have algal cells living inside their own cells.

Figure 9 shows a coral and an enlarged coral cell.

Algal cells photosynthesise to produce glucose (C₆H₁₂O₆).

Write the balanced symbol equation for photosynthesis.

Explain one way the algal cells use glucose for growth.

Suggest one advantage to the algal cells of living inside the coral cells.

An increase in water temperature can cause coral to release the algal cells.

Releasing algal cells can result in the death of coral.

Suggest why coral may not survive without the algal cells.

Scientists investigated how the concentration of oxygen in the water around one coral changed during the day.

Figure 10 shows the results.

Explain the changes in oxygen concentration between A and B.

At C the rate at which oxygen is being produced equals the rate at which oxygen is being used.

Give the reason why.

Table 1 shows the concentration of some substances outside a cell and inside a cell.

Why do sodium ions move into the cell?

Use information from Table 1.

Calculate how many times greater the potassium ion concentration is inside the cell compared with outside the cell.

Name the process that releases energy in cells.

Which process needs energy to move a substance into a cell?

Tick (✓) one box.

Give two factors that affect the rate of diffusion.

Students investigated the change in mass of potato pieces in different concentrations of sugar solution.

Figure 7 shows some of the equipment used.

Describe a method to investigate the effect of different concentrations of sugar solution on the change in mass of potato pieces.

Figure 3 shows part of one liver cell.

The photograph was taken with an electron microscope.

Name structure X.

Describe the function of mitochondria.

Protein synthesis occurs at ribosomes.

Describe the structure of a protein molecule.

The storage substance in liver cells is a carbohydrate.

Name the carbohydrate storage substance found in liver cells.

Electron microscopes have higher resolving power than light microscopes.

What is the resolving power of a microscope?

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An electron microscope has a magnification of × 650 000

The length of a cell structure in an image from the electron microscope was 27 mm

Calculate the real length of this cell structure in mm

Give your answer to 2 significant figures.

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?

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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.

A scientist investigated the effect of exercise on reducing the risk of some medical conditions.

The investigation involved two groups of people.

One group walked quickly and the other group ran.

The people in the walking group exercised for more time than the people in the running group.

Each group transferred the same amount of energy.

Table 7 shows data from the investigation.

Name two factors that should be controlled.

Do not refer to amount of energy transferred, age or sex in your answer.

Blood pressure measures how hard the blood is forced against the walls of the arteries.

Regular exercise makes the heart muscle stronger.

A stronger heart can pump more blood with less effort so the forces on the walls of the arteries decrease.

Suggest why walking reduces the risk of high blood pressure more than running reduces the risk of high blood pressure.

Explain how a high concentration of cholesterol in the blood can cause coronary heart disease.

A student walked quickly for 15 minutes.

Figure 11 shows the effect walking quickly had on the student’s heart rate.

Determine the rate of increase in heart rate of the student at 8.5 minutes.

Use Figure 11.

Explain why heart rate needs to increase during exercise.