Download public exam_infectious diseases

ECF Saint Too Canaan College
Biology public exam exercise
Infectious diseases
Name: ___________________
Class: ______ (
)
Date: _____________________
CE 2002_I_Q.2(a)(ii)
1.
Give an example of an infectious disease that can be prevented by wearing the condom
(1 mark)
CE 2002_I_Q.2(c)(iv)
2.
The following is taken from a pamphlet on the guidelines for lunch box suppliers to Hong Kong
schools:
Explain why points 1 and 3 are crucial in ensuring that food in the lunch boxes is safe to eat.
(2 marks)
CE 2003_I_Q.4(c)(iii)
3.
People may be infected with cholera through eating contaminated seafood. Besides vaccination,
suggest two ways to reduce the risk of cholera infection through eating seafood.
(2 marks)
Bio_public exam_infectious diseases
P.1
CE 2007_I_Q.7(b)
4.
Antibiotic is a drug commonly used to treat bacterial infections. In recent years, there have been
more reported cases of resistant forms of bacteria strains found in hospitals. The graph below
shows the percentage of the resistant form in a particular bacterial population and the amount of
antibiotics used in one particular hospital each year from1995 to 2004:
(a) Explain why the increased amount of antibiotics used will lead to the rise in the percentage of
the resistant form in the bacterial population.
(4 marks)
(b) Some patients in hospitals will have a higher death rate if infected with resistant forms of
bacteria. Suggest one group of these patients and give an explanation.
(2 marks)
(c) If you were a doctor, suggest two practices that you could adopt to slow down the rise of the
resistant forms of bacteria.
(2 marks)
Bio_public exam_infectious diseases
P.2
AL 2005_I_Q.3
5.
Complete the following paragraph with suitable word(s):
(4 marks)
Cholera is caused by a bacterium, Vibrio cholera, which is transmitted directly through (a)
_____________________________________. In sub-tropical areas, there is a distinct seasonal
pattern of this disease, with the highest incidence in the (b)___________________ season. The
incidence of cholera can be reduced by taking proper precautionary measures such as
(c)___________________________________ and (d)__________________________________.
DSE PP_B_Q.1
6.
For each of the infectious diseases listed in Column 1, select one of the methods listed in
Column 2 that helps to protect people from contracting the disease. Put the appropriate letter in
the space provided.
Column 1
Cholera
___________
Dengue fever ___________
(2 marks)
Column 2
A. using serving chopsticks and spoons at meal times
B. boiling water before drinking
C. wrapping up rubbish properly before disposal
D.
E.
wearing a face mask in crowded places
getting rid of stagnant water
Bio_public exam_infectious diseases
P.3
AL 2003_I_Q.13(a)(b)(c)(d)
7.
Read the following passage and then answer the questions that follow.
Biological weapons
Both the smallpox virus and the anthrax bacterium captured worldwide attention when they were used as
biological weapons. Smallpox is a highly infectious human disease which can be transmitted by air within a short
distance. Anthrax is essentially a disease of farm animals though humans are susceptible. Unlike smallpox, anthrax
does not spread from person to person.
In the bio-terrorism incident in the U.S.A. in 2001 , it was suspected that anthrax spores packed in letters were
dispersed through mail-sorting machines causing infection to postal workers. As a post-exposure measure, postal
workers were given ciprofloxacin, a broad spectrum antibiotic, which kills the anthrax bacterium. However,
prolonged antibiotic treatment is not recommended by U.S. health officials as this will further increase health risk.
The initial symptoms of anthrax caused by infection through inhalation are flu-like, e.g. cough and fever. In
comparison, the symptoms of smallpox closely resemble those of chickenpox, which is not fatal. Both smallpox and
chickenpox cause watery pustules (i.e. vesicles) to develop on the skin at the initial stage of infection. These pustules
contain the highly infectious viral particles. Anthrax and smallpox can be fatal if not treated early. At present,
vaccination against smallpox and anthrax is only recommended to high-risk populations.
Although smallpox has been eradicated in 1980, some nations still keep a stock (collection) of its virus. It is
debatable whether stocks of the smallpox virus and the anthrax bacterium should be kept by nations.
(a) Other than size and size-related features, give two biological features that are possessed by
both the smallpox virus and the anthrax bacterium which enable them to be used as biological
weapons.
(b) Suggest a measure to control the spread of smallpox virus from infected patients.
(2 marks)
(1 mark)
(c) As a broad spectrum antibiotic, what undesirable effect will ciprofloxacin have on the
microbial community in the body?
(2 marks)
(d) Explain why prolonged antibiotic treatment will cause health risk to a human community.
(3 marks)
Bio_public exam_infectious diseases
P.4
AL 2006_I_Q.13(a)-(e)
8.
Read the following passage and then answer the questions that follow.
(a) Explain why the production of antibiotics by microorganisms is important to their survival in
the natural environment.
(2 marks)
(b) Explain why the crowded conditions in the prison led to the quick and wide spread of
tuberculosis among the prisoners in the Soviet Union.
(2 marks)
Bio_public exam_infectious diseases
P.5
8.
(c) Antibiotics could control tuberculosis well in the past but subsequently failed to cure the
diseased prisoners and eventually lost its effectiveness. Account for this.
(4 marks)
(d) The strain of Mycobacterium tuberculosis found in New York City was identical to that in the
Soviet Union. Suggest two explanations for this phenomenon.
(2 marks)
(e) Suggest two ways in which individuals can contribute to slowing down the loss of
effectiveness of antibiotics in treating diseases in the community. Support your answer with
biological rationales.
(4 marks)
DSE_2012_IB_Q.2
9.
Dengue Fever is a vector borne disease transmitted by mosquitoes. The table below shows two
methods adopted by the Government to break the transmission link of this disease. Complete
the table below to show how each method works and comment on its advantage or
disadvantage.
(4 marks)
Method
How it works
Comment (advantage or disadvantage)
Spraying of pesticides
or larvicidal oil around
mosquito’s habitat
Clearance of
accumulated water in a
neighbourhood
Bio_public exam_infectious diseases
P.6
DSE PP_IB_Q.6
10. A test was carried out to investigate the effects of four antibiotics against a species of bacteria
isolated from a patient. The bacteria were inoculated on the surface of an agar plate. Four
filter-paper discs (each with a diameter of 5 mm) soaked with different antibiotics A, B, C and D
were placed on the surface of the agar. The agar plate was then incubated to allow the growth of
the bacteria. If bacterial growth is inhibited by an antibiotic, a clear zone surrounding the
filter-paper disc soaked with the antibiotic will be observed after 24 hours. The results of the test
are shown below:
The following table shows the diameter of the clear zone measured in each of the filter-paper
discs:
Antibiotic
Diameter of the clear zone (mm)
A
13
B
5
C
10
D
21
(a) Explain why the agar plate should be incubated at 37°C.
(b) (i)
(1 mark)
Based on the results, arrange the four antibiotics in descending order of effectiveness at
inhibiting bacterial growth.
(1 mark)
Bio_public exam_infectious diseases
P.7
10. (b) (ii) Explain your reasoning in determining the order in (i).
(3 marks)
(c) Antibiotic B has been commonly used. It was the most effective antibiotic against the same
bacteria a few years ago. Explain the result of antibiotic B in this test.
(4 marks)
Bio_public exam_infectious diseases
P.8
ECF Saint Too Canaan College
Biology public exam exercise – Infectious diseases answer
1.
AIDS / hepatitis B, C or E / gonorrhea / syphilis
1
(1)
2.
Cooking the food thoroughly is to kill the microorganisms in the food.
The shorter the time for the food to be left at room temperature, the less the
microorganisms can grow in the food.
1
1
(2)
3.
Cook the seafood thoroughly
Irradiate seawater used in fish tanks with UV light
1
1
(2)
4.
(a)
(b)
(c)
Genetic variations exist among the bacteria in their resistance against the antibiotic.
1
The increase in the amount of antibiotics kills non-resistant form while the resistant
form survives.
The resistant form continues to reproduce / produce more of its own kind.
The number of resistant form of bacteria increases faster.
1
Any group with weak immune system plus correct example, e.g. children, elderly,
AIDS patients, cancer patient after treatment, patients taking immunosuppressor
durgs.
1
Prescribe antibiotics only when necessary.
Instruct the patient to finish the whole course of prescription.
Use narrow spectrum antibiotics.
1
1
1
1
1
(1)
(8)
5.
(a)
the intake of contaminated food / water
1
(b)
summer
1
(c)
．
．
．
．
cooking food / boiling drinking water thoroughly
washing hands after going to toilets
proper disposal of sewage
proper treatment of drinking water
1
1
(1)
(1)
(4)
Bio_public exam_infectious diseases
P.9
6.
Cholera: B
Dengue fever: E
1
1
(2)
7.
(a)
any two : (1 mark each, accept reasonable alternatives)
． they are parasitic on man / pathogenic / they can cause infection / they are fatal
． fast reproduction rate
． presence of resistant phase (spore and viral particles) thus not easily destroyed
． fast mutation rate makes it difficult to develop a long lasting vaccine
． both produce symptoms similar to non-fatal disease thus delay early treatment
1
1
(1)
(1)
(1)
(b)
isolation of smallpox patients to prevent spread by air
1
(c)
being a broad spectrum antibiotic, ciprofloxacin also kills other microorganisms
． this upsets the balance of microorganism community in the body
1
1
(d)
prolonged use of antibiotic will favour the selective survival of the more resistant
bacteria
． rendering the future use of the same antibiotic not effective
． the resistant strains will continue to multiply increasing the pool of infective
1
1
1
bacteria
(9)
8.
(a)
To kill / inhibit the growth of other microorganisms in nature,
thus reducing the competition for resources / gaining more resources for their own
survival.
1
1
(b)
Tuberculosis is transmitted through air.
The bacteria would be transmitted easily over a short distance from infected
individuals to uninfected individuals in the crowded prison / uninfected individuals
have a high chance of exposure to the bacteria from infected individuals in the
1
1
crowded prison
Bio_public exam_infectious diseases
P.10
8.
(c)
(d)
In the past, the predominant population of Mycobacterium tuberculosis was sensitive
to antibiotics, so antibiotics were effective in controlling tuberculosis.
1
There were variations in the bacterial resistance against antibiotics.
Excessive use of antibiotics eliminated the sensitive strains / selected for the resistant
strains.
Resistant strains multiplied
and became the predominant populations, hence antibiotics became no longer
effective.
1
1
People carrying the resistant bacteria travelled from the Soviet Union to New York
City / the same resistant strain arose independently in New York City.
Same antibiotics were used in treating tuberculosis in the Soviet Union and New
1
(1)
1
1
York City, thus selecting the same resistant strain of bacteria in both places.
(e)
or,
or,
Take antibiotics only when necessary / avoid using antibiotics for viral disease.
This reduces exposure of the pathogens to the antibiotics.
Complete the whole course of antibiotics prescribed.
To let the antibiotics eradicate the bacterial population in the body leaving no strains
to propagate.
Take precautions against being infected / spreading one’s infection.
To reduce the chance of using antibiotics.
1
1
1
1
(1)
(1)
(14)
9.
1,
1
1,
1
(4)
Bio_public exam_infectious diseases
P.11
10. (a)

(b)
(i)
D, A, C, B (1)
(ii)


Since the bacteria were taken from a human being, the human body temperature
is therefore suitable for the growth of the bacteria. (1)

(c)
the antibiotic diffuses outward from the paper disc (1)
the farther away from the disc, the lower is the concentration of the
antibiotic (1)
a larger clear zone indicates that the antibiotic is effective in inhibiting
bacterial growth even at a lower concentration. (1)

genetic variations exist among bacteria in their resistance to antibiotic B (1)

the non-resistant strain of this bacteria has been continuously eliminated by
antibiotic B (1)
the resistant strain of this bacteria has survived and reproduced to produce
resistant offspring (1)
the population size of the resistant strain in this bacteria population increases
(1)
thus, the effectiveness of antibiotic B decreases



(1)
(1)
(3)
(4)
9
Bio_public exam_infectious diseases
P.12