Question 1Multiple choice · 1 markA* challenge
A person has a heart rate of 60 beats per minute and a stroke volume of 60 cm3.
What is the cardiac output?
- A 0.0600 dm3 min−1
- B 1.00 dm3 min−1
- C 3.60 dm3 min−1
- D 3600 dm3 min−1
Show answer
Answer: C
10 free AS Level Biology Transport & Disease questions written in the style of Cambridge Biology papers: 3 multiple-choice and 7 structured, each with its answer and mark scheme. 4 of them are A* challenge questions, built to catch the mistakes strong students still make.
This topic covers Transport in plants, Transport in mammals, Gas exchange, Infectious diseases, Immunity. Work through the questions below, then generate a full Transport & Disease paper with a fresh set every time.
Generate a full Transport & Disease paper →A person has a heart rate of 60 beats per minute and a stroke volume of 60 cm3.
What is the cardiac output?
Answer: C
The cardiac cycle is controlled by the sinoatrial node.
1 The atrioventricular valves are open during ventricular systole.
2 The atrioventricular node delays the impulse so the atria empty before the ventricles contract.
3 The Purkyne tissue carries impulses to the base of the ventricles.
Which statements are correct?
Answer: B
Which row describes the effects of tobacco smoke?
| tar | carbon monoxide | nicotine | |
|---|---|---|---|
| A | paralyses cilia, carcinogens | binds haemoglobin | increases heart rate and blood pressure |
| B | paralyses cilia, carcinogens | increases heart rate | binds haemoglobin |
| C | binds haemoglobin | paralyses cilia, carcinogens | increases heart rate and blood pressure |
| D | paralyses cilia, carcinogens | binds haemoglobin | decreases heart rate |
Answer: A
Describe the roles of B-lymphocytes and T-lymphocytes in the primary immune response to a bacterial infection.
Explain why a vaccine against one strain of influenza may not protect against a new strain.
Explain why antibiotic resistance spreads rapidly in bacterial populations.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | antigen presentation by macrophages; clonal selection of specific T-helper and B cells; T-helper cells release cytokines; B cells divide by mitosis into plasma cells secreting antibodies; memory cells formed; T-killer cells destroy infected cells antigen-presenting cells B1 clonal selection of specific lymphocytes B1 clonal expansion by mitosis B1 T-helper cytokines stimulate B cells B1 plasma cells secrete antibodies B1 memory cells B1 | 6 |
| (b) | antigenic variation: mutation changes antigens, memory cells/antibodies not complementary new strain has different antigens (antigenic variation/drift) B1 existing antibodies/memory cells not complementary B1 | 2 |
| (c) | random mutation gives resistance; selection pressure from antibiotic; resistant bacteria survive and reproduce; plasmids transferred by conjugation (horizontal transmission) mutation B1 selection by antibiotic use B1 horizontal gene transfer on plasmids B1 | 3 |
This question is about transport in plants.
Describe the pathways taken by water from the root hair cell to the xylem.
Explain how water moves up the xylem by cohesion–tension.
Describe two features of xylem vessel elements that adapt them for transport.
Describe two features of a xerophyte and explain how each reduces water loss.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | apoplast through cell walls; symplast through cytoplasm and plasmodesmata; Casparian strip forces into symplast at endodermis apoplast pathway through cell walls B1 symplast pathway through cytoplasm via plasmodesmata B1 at the endodermis the Casparian strip blocks the apoplast so water enters the symplast B1 | 3 |
| (b) | evaporation from leaves lowers water potential; water pulled up; H bonds cohesion between water molecules; adhesion to walls; continuous column under tension water evaporates from mesophyll cells and diffuses out of stomata B1 this creates tension that pulls water up the xylem B1 hydrogen bonds between water molecules (cohesion) keep the column continuous B1 adhesion to the xylem walls helps B1 | 4 |
| (c) | no end walls (continuous tube); lignified, waterproof, prevents collapse; pits Any 2 of: no end walls so form a continuous tube; lignified walls withstand tension / prevent collapse; pits allow lateral movement B2 | 2 |
| (d) | rolled leaves / sunken stomata trap humid air; thick cuticle; hairs rolled leaves / sunken stomata / hairs trap moist air, reducing the water potential gradient B1 thick waxy cuticle reduces evaporation B1 | 2 |
Water moves through the leaf by the apoplast and symplast pathways.
Distinguish between the apoplast and symplast pathways.
Explain the role of the Casparian strip in the endodermis.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | cell walls vs cytoplasm via plasmodesmata apoplast: through cell walls and spaces B1 symplast: through cytoplasm and plasmodesmata B1 | 2 |
| (b) | blocks apoplast; water enters symplast suberin blocks the apoplast pathway B1 water and ions must enter the symplast, so uptake is controlled B1 | 2 |
The cardiac cycle is controlled by the heart’s own conducting tissue.
Describe the roles of the SAN, AVN and Purkyne tissue.
| Part | Answer and marking points | Marks |
|---|---|---|
| SAN pacemaker; AVN delay; Purkyne to apex SAN initiates wave of excitation (pacemaker) B1 atria contract B1 AVN delays impulse so atria empty B1 Purkyne tissue carries impulse to apex so ventricles contract from base upwards B1 | 4 |
This question is about the gas exchange system.
Describe the distribution of cartilage, ciliated epithelium, goblet cells and smooth muscle in the trachea, bronchi and bronchioles.
Explain the roles of goblet cells and cilia in protecting the gas exchange surface.
Explain how elastic fibres in the alveolar walls aid ventilation.
Describe the effects of tar and carbon monoxide in tobacco smoke on the body.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | cartilage: C-rings trachea, plates bronchi, none bronchioles; ciliated epithelium and goblet cells in trachea, bronchi, larger bronchioles; smooth muscle in all, most in bronchioles Any 4 of: trachea: C-shaped cartilage rings; bronchi: irregular cartilage plates; bronchioles: no cartilage; ciliated epithelium and goblet cells line trachea and bronchi (fewer in bronchioles); smooth muscle present throughout, relatively more in bronchioles B4 | 4 |
| (b) | goblet cells secrete mucus that traps pathogens; cilia beat, move mucus up to throat goblet cells secrete mucus B1 mucus traps dust and pathogens B1 cilia beat to move mucus up towards the throat where it is swallowed B1 | 3 |
| (c) | stretch on inspiration; recoil to help expel air elastic fibres stretch when alveoli fill B1 they recoil during expiration, helping to push air out B1 | 2 |
| (d) | tar paralyses cilia, mucus builds up, infections; carcinogens cause cancer; CO binds haemoglobin, less O₂ carried tar paralyses / destroys cilia so mucus accumulates B1 increased chest infections / chronic bronchitis B1 tar contains carcinogens (lung cancer) B1 carbon monoxide combines irreversibly with haemoglobin (carboxyhaemoglobin), reducing oxygen transport B1 | 4 |
The primary and secondary immune responses differ.
Explain why the secondary response is faster and larger.
Describe the structure of an antibody.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | memory cells; rapid clonal expansion memory cells remain after the primary response B1 they recognise the antigen quickly B1 rapid clonal expansion produces more antibody faster B1 | 3 |
| (b) | four polypeptide chains; variable region binding site four polypeptide chains (two heavy, two light) held by disulfide bonds B1 variable regions form antigen-binding sites B1 | 2 |
Tuberculosis and malaria are infectious diseases.
Name the pathogen that causes TB and describe how it is transmitted.
Describe how malaria is transmitted.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | Mycobacterium tuberculosis; droplets Mycobacterium tuberculosis (or M. bovis) B1 airborne droplets from coughing/sneezing B1 | 2 |
| (b) | Plasmodium; Anopheles mosquito vector Plasmodium (protoctist) B1 transmitted by female Anopheles mosquito when it takes a blood meal B1 | 2 |
In the 9700 syllabus, Transport & Disease covers Transport in plants, Transport in mammals, Gas exchange, Infectious diseases, Immunity.
This page has 10 Transport & Disease questions with answers. For more, the free generator on mentorriyaz.in builds a new Transport & Disease paper with a full mark scheme each time you click.
Riyaz Shaikh has mentored IGCSE, IB and A Level students for 15+ years, one-on-one, online and in Mumbai. The hardest questions on this site are the ones he uses to find a student's weak points.
Meet Riyaz →Original Cambridge-style practice questions written for mentorriyaz.in. These are not Cambridge past paper questions, and this site is not affiliated with or endorsed by Cambridge University Press & Assessment. Updated 2026-11-04. Paper generator · mentorriyaz.in