Y11 Revision Gaseous Exchange

Q1.Our lungs help us to breathe.

The image below shows the human breathing system.

(a) (i) Name part A.

......

(1)

(ii) Give one function of the ribs.

......

(1)

(b) (i) Use the correct answer from the box to complete the sentence.

active transport / diffusion / osmosis

Oxygen moves from the air inside the lungs into the blood by the

process of ......

(1)

(ii) Use the correct answer from the box to complete the sentence.

arteries / capillaries / veins

Oxygen moves from the lungs into the blood through the walls

of the ......

(1)

(iii) Inside the lungs, oxygen is absorbed from the air into the blood.

Give two adaptations of the lungs that help the rapid absorption of oxygen into the blood.

1 ......

......

2 ......

......

(2)

(Total 6 marks)

Q2.Emphysema is a disease affecting the lungs. People with emphysema are often short of breath and find exercise difficult.

The diagram below shows an alveolus from a person without emphysema and an alveolus from a person with emphysema.

(a) Describe one difference between the alveolus from a person without emphysema and the alveolus from a person with emphysema.

......

......

(1)

(b) Explain how the difference you described in part (a) causes the person with emphysema to find exercise difficult.

......

......

......

......

......

(3)

(Total 4 marks)

Q3.Gas exchange takes place in the lungs.

The diagram shows an alveolus next to a blood capillary in a lung.

The arrows show the movement of two gases, A and B.

(a) (i) Draw a ring around the correct answer to complete the sentence.

Gases A and B move by / diffusion.
osmosis.
respiration.

(1)

(ii) Gas A moves from the blood to the air in the lungs.

Gas A is then breathed out.

Name Gas A.

......

(1)

(iii) Which cells in the blood carry Gas B?

Draw a ring around the correct answer.

platelets red blood cells white blood cells

(1)

(b) The average number of alveoli in each human lung is 280 million.

The average surface area of 1 million alveoli is 0.25 m2.

Calculate the total surface area of a human lung.

......

Answer ...... m2

(2)

(c) An athlete trains to run a marathon. The surface area of each of the athlete’s lungs has increased to 80 m2.

Give one way in which this increase will help the athlete.

......

......

(1)

(Total 6 marks)

Q4. The graph shows the effect of increasing the carbon dioxide content of the inhaled air on:

• the number of breaths per minute;

• the total volume of air breathed per minute.

(i) Describe the effect of increasing the percentage of carbon dioxide in the inhaled air on the total volume of air breathed.

......

......

......

......

(2)

(ii) Suggest why the total volume of inhaled air is not directly proportional to the number of breaths per minute.

......

......

......

......

(2)

(Total 4 marks)

Q5.(a) Diagram 1 shows part of the breathing system.

Diagram 1

(i) Use words from the box to name the parts labelled A, B, C and D.

alveolus / diaphragm / lung / rib / trachea

A ......

B ......

C ......

D ......

(4)

(ii) Parts B and C move when we breathe in.

Part B moves ......

Part C moves ......

(2

(b) A student used the apparatus shown in Diagram 2 to measure the maximum volume of air that he could breathe in one breath.
When the student breathes in, the piston moves upwards.
The piston moves back down after the student has breathed out.

Diagram 2

The student breathes in through the apparatus three times.
The drawings show the position of the piston after each of the three breaths.
The volumes are measured in cm3.

(i) Read the volume of each breath and write the volume in the table.

Breath 1 / Breath 2 / Breath 3
Volume in cm3 / ...... / ...... / ......

(3)

(ii) Calculate the mean volume of air breathed in.

......

......

Mean volume of air breathed in = ...... cm3

(2)

(c) A teacher asks the student to investigate if students who take part in sports activities can breathe in a larger volume of air than students who do not take part.

Describe briefly how the student could use the same apparatus to do the investigation.

......

......

......

......

......

......

...... (3)

Q6.Figure 1 shows a model representing the human breathing system.

The different parts of the model represent different parts of the human breathing system.

(a) (i) Which part of the human breathing system does the flexible rubber sheet represent?

......

(1)

(ii) Explain why the balloons inflate when the flexible rubber sheet is pulled down.

......

......

......

......

......

......

(3)

(b) (i) During breathing, oxygen moves into the blood.

Explain how oxygen moves into the blood.

......

......

......

......

(2)

M1.(a) (i) alveoli / alveolus

allow air sacs

allow phonetic spelling

1

(ii) any one from:

• protection (of lungs / heart)

• help you breathe / inflate lungs.

1

(b) (i) diffusion

1

(ii) capillaries

1

(iii) any two from:

• (have many) alveoli

allow air sacs

• large surface / area

• thin (exchange) surface or short diffusion pathway

accept only one / two cell(s) thick

• good blood supply / many capillaries

allow (kept) ventilated or maintained concentration gradient.

2

[6]

M2.(a) (healthy alveolus has a) larger surface area

allow larger SA:Volume ratio

accept converse for alveoli from person with emphesema

allow walls between alveoli disintegrate or fluid accumulation in alveoli

1

(b) less oxygen into the blood / muscles

less only needed once

1

(so) less respiration

ignore ref. to anaerobic respiration

1

(and therefore) less energy is released (for exercise)

do not allow energy is produced / made

do not allow energy for respiration

1

[4]

M3.(a) (i) diffusion

1

(ii) carbon dioxide

accept CO2 / CO2

do not accept CO2

1

(iii) red blood cells

1

(b) 70

if no / incorrect answer then

70 000 000

or

280 x 0.25 gains 1 mark

ignore doubling the answer

2

(c) allows more gas / oxygen / CO2
(exchange)

do not accept air

1

[6]

M4. (i) increase in CO2 concentration leads to increase in volume of air inhaled
increase of % carbon dioxide has little effect over most of range / large
increase when % carbon dioxide > 5.6 %

each for 1 mark

2

(ii) idea that
depth of breathing changes at low % carbon dioxide, in crease in % CO2
results in volume of each breath increasing without increase / little increase
in number of breaths

each for 1 mark

2

[4]

M5.(a) (i) A lung

1

B rib

1

C diaphragm

1

D alveolus / alveoli

1

(ii) (B moves) up(wards) / out / up and out

1

(C moves) down(wards) / flattens

do not allow inwards
ignore outwards

if neither mark gained allow 1 mark for correct reference to muscle contraction

1

(b) (i) 1640

1

1440

1

1720

allow max 1 for 3 correct values using of bottom of piston:

1380 + 1180 + 1480 to 1485

1

(ii) 1600

correct answer gains 2 marks

if answer incorrect allow 1 mark for evidence of
(1640 + 1440 + 1720) ÷ 3

allow ecf from (b)(i)

allow use of two numbers divided by two if one is considered anomalous:

= 1680

for 2 marks

2

(c) two groups of students − one group sports activity participants, other not

allow students as a group

1

fair test eg groups same height / same mass / same sex

1

measure air breathed in by each student / repeat previous experiment then calculate mean for group

1

(d) pointer remains still after breathing / cylinder will move down after breathing (in)

1

error reading volume less likely

allow more accurate / reliable

1

[20]

M6.(a) (i) diaphragm

accept phonetic spelling

1

(ii) (because) the volume (inside the jar) increases

maximum two marks if no reference to correct part of model

1

(causing) the pressure to decrease

1

(and) air enters the balloon

allow oxygen

1

(b) (i) (so it moves by) diffusion

do not allow osmosis or active transport

1

from a high concentration (of oxygen) to a low concentration

allow down its / oxygen concentration gradient from the air or to the blood

or

(because) there is a high(er) concentration (of oxygen) in the air or there is a low(er) concentration of oxygen in the blood

ignore reference to amount of oxygen

1

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