10 questions · Form 2 Science Bab 4: Human Health
10 questions · plays in fullscreen
Prefer reading to quizzing? All 10 questions are listed below with the answer and explanation under each one.
1. What is an antigen?
Answer: B
An antigen is a foreign protein or molecular structure on pathogens that triggers white blood cells to produce specific antibodies.
2. Which enzyme present in tears and saliva helps destroy bacterial cell walls as part of the first line of defence?
Answer: C
Lysozyme is an antibacterial enzyme in secretions like tears and saliva that breaks down bacterial cell walls.
3. A person bitten by a venomous snake is immediately injected with antivenom containing ready-made antibodies. What form of immunity is this?
Answer: A
Injecting manufactured antiserum/antibodies directly into a patient provides immediate protection via artificial passive immunity.
4. What is the primary mechanism utilized by the second line of defence to neutralize pathogens?
Answer: B
The second line of defence uses non-specific white blood cells (phagocytes) to perform phagocytosis, engulfing and destroying pathogens.
5. Which factor is a primary cause of non-infectious cardiovascular disease?
Answer: B
Cardiovascular diseases are non-infectious conditions linked to lifestyle factors like unhealthy diets, smoking, and physical inactivity.
6. A newborn baby acquires antibodies through its mother's breast milk. What type of immunity is this?
Answer: C
Receiving pre-formed antibodies naturally through colostrum or breast milk provides natural passive immunity.
7. Which of the following diseases is classified as non-infectious?
Answer: C
Diabetes mellitus is caused by genetic factors or lifestyle habits (lack of insulin production/sensitivity) and cannot be transmitted between people.
8. Which action helps break the transmission chain of waterborne infectious diseases?
Answer: B
Boiling water kills pathogens like *Vibrio cholerae* and *Salmonella typhi*, preventing waterborne infection.
9. A student recovers naturally from chickenpox and becomes immune to getting it again. What type of immunity has been acquired?
Answer: A
Recovering from an infection causes the body to produce its own antibodies and memory cells naturally, yielding natural active immunity.
10. What happens when an antibody binds to its matching target antigen?
Answer: A
Antibody-antigen binding neutralizes toxins or clumps pathogens (agglutination), making them easier for phagocytes to engulf and digest.