Respiration

Explain why a person's heart rate increases when they are running compared with when they are at rest.

Figure 9 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 9

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

During a race, athletes respire aerobically and anaerobically.

Figure 10 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 11.

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

The drop of liquid in Figure 11 is at 20 mm.

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

Draw, on Figure 12, 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.

Figure 1 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 1

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

During a race, athletes respire aerobically and anaerobically.

Figure 2 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 3.

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

The drop of liquid in Figure 3 is at 20 mm.

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

Draw, on Figure 4, 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.

Figure 9 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 10 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.

_........ beats per minute

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

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

In humans, gas exchange occurs in the alveoli of the lungs.

Figure 6 shows the structure of an alveolus and its blood supply.

Which process moves carbon dioxide from the blood into the alveolus?

State one adaptation of an alveolus that increases the rate of gas exchange.

Describe how blood is moved from the heart to the lungs.

Figure 7 shows the heart rate of a person before, during and after exercise.

Describe the trend shown in Figure 7.

Use data from Figure 7 to support your answer.

Explain the trend shown in Figure 7 from 5 minutes to 25 minutes.

The stroke volume is the volume of blood pumped during one beat of the heart.

At 25 minutes the stroke volume was 0.13 dm³.

Calculate the cardiac output of the heart of this person at 25 minutes.

Use the equation

cardiac output = stroke volumeheart rate

_........ dm³ per minute

A student investigated the effect of glucose concentration on the rate of anaerobic respiration in yeast.

The student used five concentrations of glucose: 5 %, 10 %, 15 %, 20 % and 25 %.

A teaspoon of dried yeast was added to 20 cm³ of the 5 % glucose concentration in a measuring cylinder.

A drop of washing up liquid was added and the mixture was stirred.

A reaction occurred and bubbles collected as foam on the surface of the mixture.

The height of the foam was measured after five minutes.

This method was repeated for each concentration of glucose.

Describe how to set up a control for this investigation.

State how the scientist could improve this investigation to increase the rate of the reaction.

The results of this investigation are shown in Figure 5.

The student thought one of the results was anomalous.

Explain which of these results is anomalous.

Explain why the height of the foam was greatest for the 25 % glucose concentration.

Figure 6 shows a human heart.

Draw arrows on Figure 6 to show the direction of blood flow through the left side of the heart.

Name the main blood vessel that carries deoxygenated blood into the heart.

Figure 7 shows the heart rate and stroke volume of a person when at rest and when doing exercise.

Calculate the difference in cardiac output when at rest and when doing exercise.

Give your answer to 3 significant figures and include units in your answer.

_........

Explain why the cardiac output needs to increase during exercise.

Respiration occurs in cells.

Why do cells respire?

An athlete runs every day as part of their training.

Explain why the breathing rate of the athlete increases when running.

When the athlete is running, their muscle cells use both aerobic respiration and anaerobic respiration.

State two differences between aerobic respiration and anaerobic respiration.

Bromothymol blue (BTB) solution is an indicator of pH.

Figure 10 shows the colour of BTB at different pH levels.

When air is passed through green BTB, for one minute, the solution stays green.

When a person breathes out through a straw into BTB for one minute the solution turns yellow.

Explain why the air breathed out turns the BTB solution yellow.

*(ii) Devise a plan, using green BTB solution, to investigate the amount of carbon dioxide in the air athletes breathe out after they have been running at different speeds.

Include:

• how you would use green BTB solution.

• how you would control at least two variables.

Respiration occurs in cells.

Why do cells respire?

An athlete runs every day as part of their training.

Explain why the breathing rate of the athlete increases when running.

When the athlete is running, their muscle cells use both aerobic respiration and anaerobic respiration.

State two differences between aerobic respiration and anaerobic respiration.

Bromothymol blue (BTB) solution is an indicator of pH.

Figure 2 shows the colour of BTB at different pH levels.

When air is passed through green BTB, for one minute, the solution stays green.

When a person breathes out through a straw into BTB for one minute the solution turns yellow.

Explain why the air breathed out turns the BTB solution yellow.

A scientist placed pondweed into two sealed test tubes containing green BTB solution.

Test tube A was kept in the dark. Test tube B was kept in the light. All other conditions were kept the same. Figure 3 shows these test tubes at the start of the investigation.

Figure 4 shows the colour of the BTB solution after 5 hours.

Explain the results for tube A and tube B shown in Figure 4.

Figure 11 shows a cross-section of an artery and a vein.

(Source: © The University of Kansas Medical Center)

Figure 11

Explain one difference between the artery wall and the vein wall shown in Figure 11.

Name one structure that is found in veins but not found in arteries.

A human body has 5 dm³ of blood.

At rest 20% of the blood travels to the muscles.

During exercise 60% of the blood travels to the muscles.

Calculate the volume of blood travelling to the muscles during exercise.

_........ dm³

Explain one reason why there is an increase in blood flow to muscles during exercise.

*(c) Figure 12 shows the structure of the human heart.

Explain how the structure of the heart is related to its function.

Figure 7 shows a single-celled pond organism (Amoeba proteus).

Which row of the table allows the net diffusion of oxygen into Amoeba proteus ?

Amoeba proteus uses oxygen for aerobic respiration.

Complete the equation for aerobic respiration.

glucose + oxygen _........ +_........ (+ energy is released)

Humans breathe faster when they exercise.

Which two changes allow the rate of respiration in the muscle to increase?

Figure 8 shows breathing data for a human at rest and when running at 5 metres per second on a running machine.

Calculate the mean volume of air breathed per minute when running at 5 metres per second.

Give your answer to one decimal place.

_........ dm³ per minute

Devise an investigation to compare the mean number of breaths per minute for men, with the mean number of breaths per minute for women, when running at 5 metres per second on a running machine.

Whilst running, the leg muscles of an athlete tightened up, causing cramp.

Name the product of anaerobic respiration that can cause cramp.

Figure 11 shows ciliated epithelial cells from the airways of a human as seen using a light microscope.

Draw the cell labelled A in the box below.

Label three parts of this cell on your diagram.

State the function of the ciliated epithelial cells in the airways of the human breathing system.

Figure 12 shows equipment used to investigate the rate of respiration in maggots.

As the maggots respire, the drop of coloured liquid moves towards the test tube.

Figure 13 shows the position of the drop of coloured liquid after ten minutes.

Use information from Figures 12 and 13 to calculate the mean rate of respiration of the maggots in mm per minute.

_........ mm per minute

*(c) Explain how alveoli in human lungs are adapted for gas exchange.

Include the names of the gases that are being exchanged.

Figure 3 shows ciliated epithelial cells from the airways of a human as seen using a light microscope.

Draw the cell labelled A in the box below.

Label three parts of this cell on your diagram.

State the function of the ciliated epithelial cells in the airways of the human breathing system.

Figure 4 shows equipment used to investigate the rate of respiration in maggots.

As the maggots respire, the drop of coloured liquid moves towards the test tube.

Figure 5 shows the position of the drop of coloured liquid after ten minutes.

Use information from Figures 4 and 5 to calculate the mean rate of respiration of the maggots in mm per minute.

_........ mm per minute

Describe a control for this investigation.

Which row of the table shows the endocrine gland and hormone involved in the control of blood glucose concentration?

State a target organ for the hormone that controls blood glucose concentration.

People with a high BMI are more likely to develop type 2 diabetes. Figure 8 shows the mass, height and BMI for two people.

Use the formula to calculate the BMI for person A

Person B develops type 2 diabetes.

Describe two lifestyle changes person B should make to help to control their blood glucose concentration.

Which row of the table shows the type or types of respiration that use glucose?

A scientist measured the rate of respiration in a person when sleeping and then running at different speeds.

Figure 9 shows the results.

Explain the trend shown in Figure 9.

A slide of potato cells was viewed using a light microscope.

Figure 12 is a drawing of the slide showing starch grains in the potato cells.

Calculate the mean number of starch grains in potato cells P, Q and R.

_........ starch grains

Which structures are found in plant cells but are not found in animal cells?

A scientist investigated how the length of starch grains in potatoes changed when the potatoes were stored in the dark.

Figure 13 shows a potato after being stored in the dark.

Three potatoes were used in the investigation.

The length of starch grains in potato 1 were measured at the start.

The length of starch grains were measured in potato 2 after 5 weeks in the dark.

The length of starch grains were measured in potato 3 after 10 weeks in the dark.

Figure 14 shows the results.

Calculate the percentage difference in the mean length of starch grains in potato 2 at 5 weeks and in potato 3 at 10 weeks.

_........ %

State two variables the scientist should have controlled to improve this investigation.

The starch grains in the potatoes became smaller as the starch was converted into glucose.

State why the potatoes need glucose.

*(c) Figure 15 shows a diagram of some equipment that can be used to investigate the rate of photosynthesis.

Devise a plan to investigate the effect of light intensity on the rate of photosynthesis.

Include variables you would need to control.

A slide of potato cells was viewed using a light microscope.

Figure 3 is a drawing of the slide showing starch grains in the potato cells.

Calculate the mean number of starch grains in potato cells P, Q and R.

Which structures are found in plant cells but are not found in animal cells?

A scientist investigated how the length of starch grains in potatoes changed when the potatoes were stored in the dark.

Figure 4 shows a potato after being stored in the dark.

Figure 4

Three potatoes were used in the investigation.

The length of starch grains in potato 1 were measured at the start.

The length of starch grains in potato 2 were measured after 5 weeks in the dark.

The length of starch grains in potato 3 were measured after 10 weeks in the dark.

Figure 5 shows the results.

Calculate the percentage difference in the mean length of starch grains in potato 2 at 5 weeks and in potato 3 at 10 weeks.

State two variables the scientist should have controlled to improve this investigation.

The starch grains in the potatoes became smaller as the starch was converted into glucose.

State why the potatoes need glucose.

Describe how starch is broken down into glucose.

(a) Figure 5 shows a cross section of an artery and a vein.

(Source: © The University of Kansas Medical Center)

Figure 5

Measure the length of line A and the length of line B in mm.

line A_........ mm

line B_........ mm

State the ratio of the thickness of the artery wall to the thickness of the vein wall.

Give a reason why veins have valves.

Name the artery that transports oxygenated blood from the heart to the body.

A scientist investigated the relationship between exercise and the ability to run at 3 metres per second for 20 minutes.

The scientist collected data from six groups of people. Each group exercised for a different number of hours per week for six months.

There were 100 people in each group.

Figure 6 shows their results.

Describe the relationship shown by this data.

Explain why some people’s leg muscles tired quickly and developed cramp when they were running.

(a) A student investigated respiration in three different organisms.

Red hydrogencarbonate indicator was placed in each of three test tubes.

Gauze was placed in each test tube to hold the organisms.

In test tube 1 the student placed four germinating peas.

In test tube 2 the student placed four dried peas.

In test tube 3 the student placed four mealworms.

Bungs were added to each of the test tubes.

The three test tubes were left for one hour.

The equipment used is shown in Figure 10.

test tube 1 test tube 2 test tube 3

Figure 10

State two ways this method could be improved to make the results for these three organisms more comparable.

Describe a suitable control for this investigation.

Hydrogencarbonate indicator changes from red to yellow when more carbon dioxide is present.

The results for this investigation are shown in Figure 11.

Explain why the result for the germinating peas is different from the result for the dried peas.

How was the carbon dioxide produced in this investigation?

*(c) Carbon dioxide is carried in blood plasma.

Human blood also contains red blood cells and white blood cells.

Explain how the structure of red blood cells and white blood cells is related to their function.

(a) A student investigated respiration in three different organisms.

Red hydrogencarbonate indicator was placed in each of three test tubes.

Gauze was placed in each test tube to hold the organisms.

In test tube 1 the student placed four germinating peas.

In test tube 2 the student placed four dried peas.

In test tube 3 the student placed four mealworms.

Bungs were added to each of the test tubes.

The three test tubes were left for one hour.

The equipment used is shown in Figure 2.

test tube 1 test tube 2 test tube 3

Figure 2

State two ways this method could be improved to make the results for these three organisms more comparable.

Describe a suitable control for this investigation.

Hydrogencarbonate indicator changes from red to yellow when more carbon dioxide is present.

The results for this investigation are shown in Figure 3.

Explain why the result for the germinating peas is different from the result for the dried peas.

How was the carbon dioxide produced in this investigation?

Explain why cellular respiration is essential for living organisms.