1. All About Worms for Extra Credit Due March 5th
Invertebrates are animals that do not have a hard backbone (vertebrae). They
include a wide variety of animals, such as corals, worms, insects and molluscs.
This section will concentrate on worms, starting with parasitic flatworms.
A) Web site name: Centers for Disease Control
Web URL: http://www.cdc.gov/ncidod/dpd/parasites/schistosomiasis/factsht_schistosomiasis.htm
Read “What is Schistosomiasis?”
1) What causes Schistosomiasis?
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2) How many people are infected with Schistosoma? _____________________
3) How does fresh water become contaminated by Schistosoma eggs?
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4) Why are snails important in spreading the disease? ____________________
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5) What are the symptoms of Schistosomiasis? _________________________
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6) What four parts of the body can be damaged by repeated infections over
many years? ___________________________________________________
7) How long should you wait after your last exposure before a blood sample is
taken? _____________________________
8) List three parts of the world where Schistosomiasis occurs:
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9) Why do you think that swimming in chlorinated pools is “generally thought
to be safe”? ___________________________________________________
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2. 10) How long should you boil water to make it safe to drink?
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11) Why is water that has been stored for 48 hours safe for showering?
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Not all worms are harmful. Earthworms are very beneficial, as they increase
aeration of soil and so improve the yield of crops. The next article deals with
another possible benefit of earthworms.
B) Web site name: BBC News
Web URL: http://news.bbc.co.uk/2/hi/science/nature/7611522.stm
Read “Earthworms to aid soil cleanup”
12) Give examples of industrial activities that contaminated soil.
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13) Which metals are in these soils? ___________________________________
14) Why was the “Diamond Light Source” important in the study:
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15). Explain how earthworms can help in removing toxins from the soil.
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3. C) Web site name: Science in Africa
Web URL: http://www.scienceinafrica.co.za/2001/september/leech2.htm
Read “An African leech for use in microsurgery in Africa!”
16). What problem was caused by the popularity of medicinal leeches?
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17). In the past, how many leeches were used on a patient at the same time?
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18). Explain why leeches are now used around skin flaps and grafts.
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19). Which anticoagulant do leeches introduce into a bite? __________________
20). What problem do surgeons have in South Africa?
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21). What is the natural host of Aliolimnatis buntonenevis? _________________
22). What are two problems with using these leeches, and how could they be
solved?
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4. D) Web site name: Centers for Disease Control
Web URL: http://www.cdc.gov/ncidod/dpd/parasites/lymphaticfilariasis/factsht_lymphatic_filar.htm
This web site gives information about “Lymphatic filariasis” which is also
called “Elephantiasis”, a disease caused by the nematode worm Wuchereria.
23) Where in the human body do the worms live? _______________________
24) Which parts of the world have lymphatic filariasis?
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25) How long does the adult worm live? ________________________________
26) Why do tourists have a very low risk?
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27) What are the main symptoms of the disease?
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28) What does the treatment do? ___________________________________
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E) Web site name: BBC news
Web URL: http://news.bbc.co.uk/2/hi/health/7754644.stm
Read “Antioxidants cannot slow ageing”
29) What worms were used in this study? _______________________________
30) Explain the theory of “oxidative stress”.
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5. 31) Give two reasons why these tiny worms are a “useful tool” to scientists.
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32) What experiment was done using the worms, and what was the result?
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33) According to Dr Gems, what is important for reducing the risk of many “old
age” diseases?
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34) Do you agree with the statements by Pamela Mason? Explain why.
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