FACULTY OF SCIENCE DEPARTMENT OF BIOTECHNOLOGY …

FACULTY OF SCIENCE

DEPARTMENT OF BIOTECHNOLOGY

DIPLOMA IN BIOTECHNOLOGY AND FOOD TECHNOLOGY

MODULE MCB1BM2 MICROBIOLOGY II CAMPUS DFC

NOVEMBER FINAL ASSESSMENT

DATE: 29 November 2016 SESSION: 12h30-14h30 ASSESSOR(S): MR K MACLEAN INTERNAL MODERATOR: MR L ALAGIOZOGLOU EXTERNAL MODERATOR: N/A DURATION 2 HOURS MARKS 130

SURNAME AND INITIALS: __________________________________________________________ STUDENT NUMBER: __________________________________________________________ CONTACT NR: __________________________________________________________

NUMBER OF PAGES: 9 PAGES

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INSTRUCTIONS: ANSWER ALL THE QUESTIONS. ANSWER QUESTION ONE ON THE MCQ CARD ISSUED. HAND IN THE QUESTION PAPER SEPARATE FROM THE ANSWER BOOK. REQUIREMENTS: MCQ CARDS. ONE ANSWER SCRIPT PER STUDENT. ONE CALCULATOR PER PERSON. QUESTION 1 Answer the following questions on the Multiple Choice Answer Sheet provided. Before filling in the required details on your answer sheet read the instructions carefully and make sure that you fill in your choices correctly. 1. Which of the following is not considered a classical characteristic for taxonomic purposes. a) ecological characteristics b) G + C content c) genetic analysis d) All of the above are classical characteristics for taxonomic purposes. 2. A population of organisms which ends on “ales” is called: a) order b) genus c) strain d) binomial system 3. A virus with a regular polyhedron with 30 equilateral triangular

forces and 12 vertices are _________________ in shape: a) helical b) complex c) icosahelical d) Non of the above 4. The organisms which are responsible for botulism are: a) plant like organisms b) animal like organisms c) bacteria like organisms d) protozoa like organisms 5. Bacteria are generally _________ growing organisms:

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a) fast b) slow 6. The presence of natural compounds in an ecosystem can lead

to: a) microbiostasis b) bacteriostasis c) fungistasis d) all of the above 7. Which of the following is normally used by Archaea as a

mechanism for reproduction? a) binary fission b) budding c) fragmentation d) All of the above 8. Taxonomy is the science of: a) biological classification b) cultural classification c) morphological classification d) naming an organism 9. A positive Catalase test is indicated by: a) gas bubbles b) acid c) gas bubbles and acid d) none of the above 10. The largest group of Cyanobacteria is the: a) methanogens b) halophiles c) thermophiles d) thermococci e) None of the above 11. Which of the following do not have cell walls? a) halobacteria b) thermoplasms c) thermococci d) None of the above have cell walls 12. Which of the following are capable of not carrying out oxygenic

photosynthesis?

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a) purple bacteria b) green bacteria c) cyanobacteria d) archaea 13. The smallest bacteriophage known is the: a) Escherichia b) Neisseria c) Rickettsias d) Both (b) and (c) e) None of the above is correct 14. Which of the following has not been used in systematics when

classifying microorganisms. a) physiology b) epidemiology c) ecology d) All of the above have been used in systematics 15. Which of the following is extremely radiation resistant? a) Deinococci b) Aquifex c) Both (a) and (b) d) None of the above 16. Members of the genus Salmonella do what of the following: a) mineralization of organic compounds b) Spoilage of refrigerated milk c) Both (a) and (b) d) None of the above 17. Mineralisation means which of the following? a) Breakdown of organic material to inorganics b) Release of various minerals from various ores c) Use of mineral as energy sources d) None of the above 18. The process of converting ammonia to nitrate is referred to as:: a) nitrogen fixation b) nitrification c) ammonification d) denitrification

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19. The largest subgroup of the proteobacteria is the ____ proteobacteria.

a) alpha b) beta c) gamma d) delta 20. Which of the following contain bacteria that are capable of

cholera? a) Vibrio b) Halophilic Staphylococcus c) Both (a) and (b) d) None of the above 21. Rickettsia is a type of virus which causes tick bite fever. a) True b) False 22. An observable change that occurs in cells because of viral

replication is called: a) interference b) adsorption c) a tumor d) the cytopathic effect 23. In which of the following will you find the common bread mold? a) Zygomycetes b) Ascomycetes c) Basidiomycetes d) Deuteromycetes 24. Because of their lack of an observable sexual reproductive cycle,

the Deuteromycetes are also referred to as: a) fungi incompleti b) fungi imperfecti c) fungi asexuali d) fungi havnofuni 25. Which of the following is the oldest branch of eubacteria? a) Thermotoga b) Aquifex c) Cyanobacteria d) Spirochaetes

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26. Which of the following can be attributed to members of the genus Bacillus?

a) They produce certain antibiotics b) Can cause food poisoning c) Can be used as bioinsecticides d) All of the above are correct 27. In which of the following are the sexual spores haploid? a) Zygomycetes b) Ascomycetes c) Basidiomycetes d) Deuteromycetes 28. In which of the following divisions will the coenocytic hyphae be

found? a) Zygomycetes b) Ascomycetes c) Basidiomycetes d) Deuteromycetes 29. In which of the following will most of the yeasts be found? a) Zygomycetes b) Ascomycetes c) Basidiomycetes d) Deuteromycetes 30. Whooping cough is caused by members of the: a) Staphylococcus b) Streptococcus c) Mycobacteriun d) Corynebacterium 31. Which of the following is not a deleterious effect attributed to

fungi? a) spoilage of food b) deterioration of leather c) production of the immunosuppressive compounds d) decomposition of organic materials 32. Fungal spores are light and can thus remain in air for long

periods of time.

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a) True b) False 33. Most fungi are aerobic or facultative anaerobic. However, a few

are obligate anaerobes. a) True b) False 34. In which ways do viruses differ from living microbial cells? a) Viruses have acellular structures b) They have RNA or DNA never both c) Viruses are obligate intracellular parasites d) All of the above are correct 35. Centrifugation of a suspension at various speeds in order to

separate viral particles of various sizes is called: a) isopycnic centrifugation b) density centrifugation c) differential centrifugation d) variable centrifugation [35]

QUESTION 2 Write the letter of choice next to each of the statements below in your answer book. 2.1 The science of biological classification. a. hybridisation 2.2 The scientific study of organisms to ultimately b. melting temperature characterise them and arrange them in a c. numerical taxonomy orderly manner. d. phenetic classification 2.3 A population of organisms that descends from e. phenon a single organism. f. phyletic classification 2.4 A classification system based on evolutionary g. strain relationships. h. stromatolites 2.5 A classification system based on mutually i. systematics

similar attributes. j. taxon 2.6 A classification system based on the general k. taxonomy similarity of organisms, in which computers are used to calculate association coefficients. 2.7 The temperature at which the two strands of a double stranded DNA molecule will separate. 2.8 The phenomenon in which two strands of nucleic acids associate with each other because they share some degree of sequence homology. 2.9 Organisms with great similarity that are grouped together by numerical taxonomy methods.

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2.10 A generic term for the groups into which organisms are placed. [10]

QUESTION 3 Compare the reproduction of DNA and RNA viruses using a flow diagram. 20 x 0.5 [10]

QUESTION 4 4.1 Incubated chicken eggs can be used as a growth media for

viruses. Make an annotated drawing of an incubated chicken egg and clearly indicate the areas for viral innoculation. (9)

4.2 Explain what interferon is and name the two different types of

interferon. (6) [15]

QUESTION 5 Microorganisms form different products when breaking down complex organic matter (CH20) aerobically than they do under anaerobic conditions. With the aid of a flow diagram illustrate this process. [15]

QUESTION 6 6.1 Explain what Y/M shifts are and how it occurs in plants and

animals. What do you call this phenomenon? (4) 6.2 Name four fungal divisions; their common names and provide an

example of the biotechnological relevance of each division. (12) 6.3 Name five morphological features you will consider when

identifying fungi. (5) 6.4 Differentiate between populations, community and ecosystems in

microbial ecology. (4) [25]

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QUESTION 7 7.1 Give the formulae used to determine the the LD, TCD and ID50

titers of viruses. (4) 7.2 Based on morphological features briefly explain how you would identify viruses. (6) 7.3 Name and define five types of symbiosis excluding parasitism and mutualism. (10) [20]

TOTAL: 130

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MICROBIOLOGY MEMORANDUM NOVEMBER EXAMINATION 2016 QUESTION 1

1. B 2. A 3. D 4. C 5. A 6. D 7. D 8. A 9. A 10. E 11. B 12. D 13. E 14. D 15. A 16. D 17. A 18. B 19. C 20. A 21. B 22. D 23. A 24. B 25. B 26. D 27. B 28. A 29. B 30. D 31. C 32. A 33. A 34. D 35. C

[35]

QUESTION 2 2.1 K 2.2 I 2.3 G 2.4 F 2.5 D

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2.6 C 2.7 B 2.8 A 2.9 E 2.10 J

[10] QUESTION 3

QUESTION 4 4.1

(9)

3.5

3.6

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4.2

• Protein • Interferon stimulates cell to form a “Translation Inhibition Protein” • All animal cells can synthesize interferon • Interferon is species specific • LMW interferon • HMW interferon (6)

[15]

QUESTION 5

[15]

QUESTION 6 6.1

• some fungi change from yeast form (Y )- to mold form (M) • in animals, Y in host and M outside host • in plants, M in host and Y outside host Dimorphism

6.2 Zygomycota – zygomycetes – antibiotics / meat tenderizer/ food coloring / bread spoilage

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Ascomycetes – sac fungi – food and plant spoilage/ research/ food and beverage production / mushrooms Basidiomycetes – club fungi – decomposers/mushrooms, pathogens Deuteromycetes – fungi imperfecti – pathogens/antibiotics/organic acids/parasites 6.3

- Appearance of macroscopical growth - Type of spores - Hyphae - coenocytic - Hyphae - septated - Hyphae - uninucleated - Hyphae – multinucleated

6.4

Populations: Groups of one species of organisms in an environment. Communities: Mixtures of different species found together in an environment. Ecosystem: Self-regulating

biological communities - and their physical environment. [26] QUESTION 7 7.1 D50 is: The proportional distance between two dilutions, which is between the

endpoints % of mortality above 50% - 50 % of mortality above 50% - % of mortality under 50%

7.2 • DNA - RNA • Capsid - no capsid • Amount of capsomeres • Size

7.3

Mutualism – Both partners benefit. Cooperation – Both/ one benefit, not absolutely necessary for

survival. Commensalisms – One benefit, other not affected. Predation – Hunter and prey. Parasitism – One benefit, other is harmed, level of cohabitation

needed. Amensalism – One organism harms the other, often for beneficial

reason. Competition – 2 Organisms compete for same resource.

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[9]

TOTAL: 120