Vitamins, Germs & Vaccines: questions and answers
Study every question with its correct answer and explanation.
1. Which vitamin can the human body make when the skin is exposed to sunlight?
- A. Vitamin A
- B. Vitamin B12
- C. Vitamin C
- D. Vitamin D
Answer: Vitamin D
Ultraviolet (UVB) rays in sunlight trigger vitamin D production in the skin, which is why it is nicknamed the 'sunshine vitamin'. Vitamin D helps the body absorb calcium, and a long-term lack of it can cause rickets in children.
2. Night blindness is mainly linked to a lack of which vitamin?
- A. Vitamin A
- B. Vitamin B1
- C. Vitamin C
- D. Vitamin K
Answer: Vitamin A
Vitamin A is needed to make rhodopsin, the light-sensitive pigment that lets the eyes see in dim light. Carrots, pumpkin, mangoes and leafy greens contain beta-carotene, which the body converts into vitamin A.
3. Beriberi is caused by a deficiency of which vitamin?
- A. Vitamin C
- B. Vitamin B1 (thiamine)
- C. Vitamin K
- D. Vitamin E
Answer: Vitamin B1 (thiamine)
Beriberi results from a lack of thiamine (vitamin B1) and affects the nerves and the heart. It became common where people ate mostly polished white rice, because milling removes the thiamine-rich outer bran layer.
4. Goitre, a swelling of the thyroid gland in the neck, is most commonly caused by a lack of which mineral?
- A. Iron
- B. Calcium
- C. Iodine
- D. Zinc
Answer: Iodine
The thyroid gland needs iodine to make its hormones, and when iodine is scarce the gland can enlarge, forming a goitre. Adding iodine to table salt (iodised salt) is one of the most successful public-health measures against it.
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5. Which vitamin is essential for normal blood clotting?
- A. Vitamin A
- B. Vitamin B1
- C. Vitamin K
- D. Vitamin C
Answer: Vitamin K
Vitamin K is needed to make several clotting factors in the liver; the 'K' comes from 'Koagulation', the German and Danish word for clotting. Newborn babies have low vitamin K levels, which is why many hospitals give them a vitamin K injection soon after birth.
6. Worldwide, the most common cause of anaemia is a lack of which mineral?
- A. Iodine
- B. Iron
- C. Sodium
- D. Fluoride
Answer: Iron
Iron is a key part of haemoglobin, the protein in red blood cells that carries oxygen, so too little iron means less haemoglobin and often tiredness. Iron from plant foods such as spinach and lentils is absorbed better when eaten together with vitamin C–rich foods.
7. What type of organism causes malaria?
- A. A virus
- B. A bacterium
- C. A protozoan parasite (Plasmodium)
- D. A fungus
Answer: A protozoan parasite (Plasmodium)
Malaria is caused by single-celled Plasmodium parasites, which are passed to humans through the bites of infected female Anopheles mosquitoes. In 1897 Ronald Ross, working in India, showed that mosquitoes carry the malaria parasite, work that earned him the 1902 Nobel Prize.
8. The BCG vaccine, given to newborns in Bangladesh, India and many other countries, protects mainly against which disease?
- A. Polio
- B. Tuberculosis
- C. Measles
- D. Tetanus
Answer: Tuberculosis
BCG (Bacille Calmette-Guérin) protects young children in particular against severe forms of tuberculosis. TB is caused by the bacterium Mycobacterium tuberculosis, which Robert Koch identified in 1882.
9. Nationwide campaigns giving children vaccine drops by mouth have been used to fight which disease?
- A. Measles
- B. Tetanus
- C. Diphtheria
- D. Polio
Answer: Polio
The oral polio vaccine (OPV) is given as drops by mouth, which made huge door-to-door vaccination campaigns possible. In 2014 the WHO South-East Asia Region, which includes Bangladesh and India, was certified polio-free.
10. Which of these diseases is caused by a virus?
- A. Dengue
- B. Cholera
- C. Typhoid
- D. Tuberculosis
Answer: Dengue
Dengue is a viral disease spread mainly by Aedes mosquitoes, which bite during the day and breed in clean standing water. Cholera, typhoid and tuberculosis are all caused by bacteria — and antibiotics act against bacteria, not viruses.