Diseases and Immunity
Each subtopic includes About section, revision page link, 10 preview questions, and practice CTAs.
Pathogens and transmission
SubtopicPathogens and transmission under Diseases and Immunity for Grade 12 IGCSE.
Preview questions (no answers)
- 1.
Which of the following pathogens causes Tuberculosis (TB)?
A.A virus
B.A bacterium
C.A fungus
D.A protoctist
- 2.
Why is it dangerous to use a needle that has been used by someone else?
A.The needle might be blunt
B.It can transmit blood-borne pathogens like HIV or Hepatitis
C.The metal of the needle might be cold
D.It can cause a vitamin deficiency
- 3.
Which of these describes a method of direct transmission of a pathogen?
A.Pathogen transferred from an infected person via a handshake
B.Pathogen transferred from a fly to food
C.Pathogen transferred through a communal water tank
D.Pathogen transferred through contaminated air in a room
- 4.
Which of the following is a characteristic of bacteria?
A.They are always multicellular
B.They lack a nucleus
C.They are always harmful
D.They are larger than human cells
- 5.
Which statement correctly describes how a vaccine provides immunity?
A.It contains antibiotics that stay in the blood for years
B.It contains antigens that trigger the production of memory cells
C.It provides the body with ready-made antibodies against the disease
D.It changes the structure of the body's cells so pathogens cannot enter
- 6.
Which of these is a response to an infection that involves a specific immune defense?
A.The trapping of bacteria by nose hairs
B.The destruction of bacteria by stomach acid
C.The production of antibodies by B-lymphocytes
D.The inflammation of the skin at a site of injury
- 7.
What is the function of mucus in the goblet cells of the gas exchange system?
A.To provide a medium for gas diffusion
B.To trap dust and pathogens from the inhaled air
C.To produce antibodies against respiratory viruses
D.To cool down the air entering the lungs
- 8.
If a person is unable to produce 'memory cells' due to a rare genetic condition, what would be the most significant impact on their health?
A.They would suffer from repeated, severe infections by the same pathogens because their immune system would treat every exposure as a 'first time'.
B.Their blood would not be able to carry oxygen effectively after an infection.
C.They would become immune to all diseases automatically because their body wouldn't remember how to be sick.
D.Their skin would become much thinner and more prone to mechanical damage.
- 9.
How does the use of insecticide-treated nets help break the transmission cycle of malaria?
A.It acts as a physical barrier and a chemical agent that kills the vector before it can bite a human.
B.It prevents the malaria parasite from leaving the human's skin during a fever.
C.It filters the air so that the protozoa cannot be inhaled by the sleeping person.
D.It attracts the mosquitoes away from stagnant water so they cannot lay eggs.
- 10.
Which of these is a mechanical barrier specifically found in the human eye to prevent pathogen entry?
A.The constant flushing action of tears and the blinking of eyelids.
B.The layer of keratin on the surface of the cornea.
C.The high concentration of hydrochloric acid in the vitreous humor.
D.The presence of cilia on the surface of the retina.
Download the worksheet for Diseases and Immunity - Pathogens and transmission to practice offline. It includes additional chapter-level practice questions.
Antibodies and vaccination
SubtopicAntibodies and vaccination under Diseases and Immunity for Grade 12 IGCSE.
Preview questions (no answers)
- 1.
How do memory cells differ from regular lymphocytes?
A.They are much larger
B.They live much longer in the body
C.They can only be found in the liver
D.They do not have a nucleus
- 2.
Which of the following is an example of artificial active immunity?
A.Receiving a rabies vaccine after a bite
B.Catching a cold from a friend
C.Getting a polio vaccination as a child
D.Receiving antibodies through breast milk
- 3.
Which immune system component is responsible for the 'memory' of a previous infection?
A.Platelets
B.Memory lymphocytes
C.Plasma proteins
D.Phagocytes
- 4.
Which of these is NOT a method by which antibodies help destroy pathogens?
A.Causing agglutination
B.Neutralizing toxins
C.Providing the pathogen with nutrients
D.Opsonization (marking for phagocytosis)
- 5.
Which statement about the 'secondary immune response' is true?
A.It produces fewer antibodies than the primary response
B.It is triggered by the same antigen that caused the primary response
C.It relies entirely on phagocytes rather than lymphocytes
D.It only occurs if the person is given a second different vaccine
- 6.
Why is there a delay (lag phase) between the first exposure to an antigen and the production of antibodies?
A.The body has to wait for the pathogen to die first
B.It takes time for the specific lymphocyte to be identified and undergo clonal expansion
C.The antibodies are being held in the gallbladder
D.The person's temperature must rise before antibodies can be made
- 7.
Which of the following is a role of the 'heavy chain' in an antibody?
A.It forms part of both the constant and variable regions
B.It is only involved in binding to glucose
C.It is the only part of the antibody that contains sulfur
D.It is always shorter than the light chain
- 8.
What determines the specificity of an antibody for its antigen at the molecular level?
A.The total number of amino acids in the heavy chain
B.The specific arrangement and properties (charge, hydrophobicity) of amino acids in the hypervariable loops
C.The presence of a carbohydrate group on the constant region
D.The amount of energy available in the B-cell
- 9.
Which of the following describes the 'clonal expansion' phase of the immune response?
A.The destruction of infected cells by cytotoxic T-cells
B.The rapid mitotic division of an activated B-lymphocyte into a large population of identical cells
C.The movement of B-cells from the bone marrow to the thymus
D.The shrinking of the lymph nodes after an infection is over
- 10.
In an experiment, if the disulfide bonds of an antibody are chemically reduced (broken), what is the most likely outcome?
A.The antibody will become more flexible and bind better
B.The antibody will dissociate into individual heavy and light chains, losing its functional shape
C.The antibody will turn into a T-cell receptor
D.The antibody will only be able to bind to glucose
Download the worksheet for Diseases and Immunity - Antibodies and vaccination to practice offline. It includes additional chapter-level practice questions.
Active and passive immunity
SubtopicActive and passive immunity under Diseases and Immunity for Grade 12 IGCSE.
Preview questions (no answers)
- 1.
Which of these is a characteristic of artificial active immunity?
A.It is achieved through vaccination.
B.It provides immediate protection.
C.It does not involve memory cells.
D.It only lasts for a few days.
- 2.
Why is it necessary to have multiple vaccinations for certain diseases like Tetanus?
A.To keep the memory cell count high enough for protection.
B.Because the first vaccine is always fake.
C.To make the person allergic to the disease.
D.To ensure the antibodies are turned into red blood cells.
- 3.
Which process describes the transfer of antibodies from mother to child via the placenta?
A.Natural passive immunity
B.Artificial passive immunity
C.Natural active immunity
D.Artificial active immunity
- 4.
Which of the following would NOT result in active immunity?
A.Catching a viral infection
B.Being injected with an antitoxin
C.Receiving a weakened bacterial vaccine
D.Exposure to a low dose of a live pathogen
- 5.
Passive immunity is often referred to as 'borrowed' immunity. Why is this an appropriate term?
A.The body must pay back the antibodies to the donor.
B.The antibodies are produced by another organism and are temporary in the recipient.
C.The recipient's immune system 'borrows' the DNA of the pathogen.
D.It only works if the recipient has a similar blood type to the donor.
- 6.
If a person is exposed to a pathogen for which they have previously been vaccinated, the concentration of antibodies in their blood will:
A.Remain at zero
B.Increase very slowly over several weeks
C.Increase very rapidly within a few days
D.Decrease as the vaccine is used up
- 7.
What is the primary role of B-lymphocytes in the development of active immunity?
A.They directly kill infected body cells using enzymes.
B.They differentiate into cells that produce specific antibodies.
C.They act as a physical barrier to prevent pathogen entry.
D.They transport antigens to the liver for excretion.
- 8.
What determines whether a lymphocyte will become a memory cell or a plasma cell during clonal expansion?
A.The type of pathogen (bacteria vs virus).
B.The concentration of oxygen in the blood.
C.Complex signaling pathways and cytokine concentrations during the immune response.
D.The age of the person being infected.
- 9.
An individual is allergic to the horse proteins used in an antivenom. What alternative could be used to provide artificial passive immunity?
A.Giving the person a small dose of the snake venom itself.
B.Using human-derived hyperimmune globulin.
C.Giving the person a massive dose of Vitamin C.
D.Waiting for the person's own body to produce a primary response.
- 10.
What is the biological advantage of active immunity over passive immunity?
A.It provides immediate protection in emergencies.
B.It does not require the use of energy by the host's cells.
C.It results in long-term protection due to the formation of memory cells.
D.It can be passed from a father to his offspring genetically.
Download the worksheet for Diseases and Immunity - Active and passive immunity to practice offline. It includes additional chapter-level practice questions.