Worksheet: Bacteria
A) Web site name: Cells Alive
Web site address: http://www.cellsalive.com/cells/bactcell.htm
Look at the diagram of a bacterial cell and click on the labels to get details.
1). What does the Nucleoid contain? __________________________________
2). Are there more “ribosomes” or “flagellum” shown in the diagram? _______
Click on “Cell wall”
3). What is the function of the capsule? ________________________________
4). What is the bacterial cell wall composed of ? _________________________
5). What shape is a “coccus” bacterium? _______________________________
6). What is the function of pili? ___________________________________
Click on “Microbiology” at the top left of the screen, and then “Dividing Bacteria”
7). How do bacteria reproduce? ______________________________________ _____________________________________________________________
8). Why is the earth not covered with bacteria? _____________________________________________________________
9). What happens in the “lag” phase? _________________________________
_____________________________________________________________
Click on “Microbiology” at the top left of the screen, and then “Parasites”
10). Why is Cryptosporidium increasingly important? ____________________
____________________________________________________________
11). What diseases can Entamoeba cause? _______________________________ _____________________________________________________________
12). There is a rapid influx of ________________ into a contacted cell.
13). Which animal carries Giardia? ______________________________
14). What are the two “eyes” on Giardia? _____________________________
B) Web site name: FSCJ
Web site address: http://web.fscj.edu/David.Byres/bacteria.html
15). Can most bacteria cause disease? ________________
16). Give an example of a bacterium that cannot live outside human cells: ____________________________
17) What is “colonisation resistance”? _________________________________ _____________________________________________________________
18). What problems can be caused by taking antibiotics? ___________________ __________________________________________________________________________________________________________________________
19). What vitamin is produced by bacteria in the gut? ______________________
20). Why is the stomach usually sterile? ________________________________
21). What are three bacteria found in the small bowel (small intestine)? _____________________________________________________________
22). Where is E. coli usually found? ___________________________________
23). Who is often infected with Staph. aureus? ___________________________
24). Where are spirochaetes found? ____________________________________
C) Web site name: University of Kansas
Web site address: http://pingpong.ki.se/public/pp/public_courses/course05589/published/1320249757101/resourceId/5539668/content/infoweb/node-3213500/What%20the%20Heck%20is%20an%20E.coli.pdf
25). What does the “E.” in E. coli stand for ? ____________________________
26). How much of the bacteria in an adult’s intestine is E. coli? ___________ %
27). When was Escherichia first isolated and characterized? _______________
28). What parts of the body usually do not contain “helpful” bacteria? _____________________________________________________________
29). Which strain of E. coli causes hemorrhaging? ________________________
30). Which toxin does this strain produce? ______________________________
31). What problems, apart from hemorrhaging, does this strain cause to people who are infected with it? _________________________________________ _____________________________________________________________
D) Web site name: New Scientist magazine
Web URL: http://www.newscientist.com/article/dn4054-antibiotic-ban-cuts-drug-resistant-bugs.html
Read “Antibiotic ban cuts drug resistant bugs”
32). What did the WHO report conclude in August 2003? _____________________________________________________________
33). Why are low doses of antibiotics used in animal feed? _________________
_____________________________________________________________
34). Which country is the world’s largest exporter of pork? ________________
35). What change was seen in the percentage of Enterococcus that were antibiotic resistant?
Before the ban: _________ % resistant, after the ban ________ % resistant.
36). List any household items that now routinely contain antibiotics, or other anti-bacterial chemicals: ______________________________________
E) Web site name: Centers for Disease Control
Web URL: http://www.cdc.gov/std/Chlamydia/STDFact-Chlamydia.htm
37). What serious complications can Chlamydia cause? __________________
_____________________________________________________________
38). What is the estimated number of infections annually? __________________
39). How often does CDC recommend testing for Chlamydia in sexually active women aged 25 or younger? ___________________
40). What is the treatment for chlamydia? _____________________
Commercial companies, such as Monsanto, also use bacteria to add genes to crop plants to produce a “transgenic” plant. This is often called “recombinant DNA”, because it re-combines DNA from different species.
F) Web site name: Monsanto Inc.
Web site address: http://web.fscj.edu/David.Byres/monsanto.html
41). What enzymes were needed to help transfer genes between species? __________________________________________________________________________________________________________________________
42). What was the first commercial application of recombinant DNA technology?
__________________________________________________________________________________________________________________________
43). Which bacterium is used by Monsanto for introducing genes into plants? _____________________________________________________________
44). Which crops are hard to grow from single cells? ______________________
45). Roughly what percentage of potato cells accept new genes? __________%
46). What is the difference between traditional plant breeding and plant biotechnology? ________________________________________________ __________________________________________________________________________________________________________________________
47). What is Bacillus thuringiensis ? ___________________________________ _____________________________________________________________
48). How does this bacteria kill pests? __________________________________ _____________________________________________________________
49). Why are chemical insecticides rarely used in Africa? __________________ _____________________________________________________________
Some people are concerned about the process of moving genes from one species to another ( recombinant DNA or genetic engineering ). The last website looks at some of the potential problems
G) Web site name: San Francisco State University
Web site address: http://online.sfsu.edu/%7Erone/GEessays/gedanger.htm
Click on one of the essays about Genetic engineering.
50). Which essay did you pick? _______________________________________ __________________________________________________________________
51). Briefly summarize the essay: _____________________________________ ______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________