problem 1) What sources of water are (a) most likely, (b) least likely to contain pathogenic bacteria?
problem 2) Put the following in the correct order for a water purification plant.
(a) Chlorination plant.
(b) Settling tank,
(c) Water tower.
(d) Slow sand filter.
(e) Coarse screen.
problem 3) Which one of the following is least likely to prevent contamination of food by houseflies?
(a) A well-fitting dustbin lid.
(b) Swatting flies.
(c) Covering food with cling-film.
(d) Efficient sewage disposal.
problem 4) Complete the following sentences by selecting the appropriate words from the list below.
In many cases, when you catch an infectious disease, your blood produces ….. (A) ….. against the infective organism. These ….. (B) ….. remain in the blood or can be rapidly made so that you are ….. (C) ….. to further attacks of the disease.
You can acquire ….. (D) …..by receiving injections of a …..(E) ….. form of the pathogen or its inactivated …..(F) ….. The injected substance is called a ….. (G) …..
immune, immunity, pathogens, disease, vaccine, antibodies, toxin, harmless, antigens
problem 5) Which of the following diseases can be prevented by inoculation?
rubella, syphilis, tuberculosis, polio, gonorrhoea, common cold, measles, haemophilia, mumps, tetanus, AIDS
problem 6) Match each disease with its correct type of vaccine.
(a) tuberculosis (i) harmless forms of virus
(b) whooping cough (ii) inactivated toxin
(c) diphtheria (iii) killed bacteria
(d) polio (iv) harmless form of bacteria.
problem 7) Antiseptics and disinfectants both kill ….. (A) …..but only ….. (B) ….. are safe to use on the skin (if sufficiently dilute).
problem 8) Complete the following sentence, selecting the most appropriate words from the list below.
An ideal …..(A) ….. against an infectious disease would be one which destroyed the ….. (B) …...but did not harm the …..(C) ….. pathogen, host, drug
problem 9) A person with a cough takes a patent cough syrup. In three days, the cough is better. Does this mean that the syrup has cured the cough? Justify your answer.