The major significance of Koch’s work was the demonstration that:

A.   Microorganisms are present in a diseased animal

B.   Microorganisms can be cultured

C.   Microorganisms cause disease

D.   Microorganisms are the result of disease

(i)   Which response (A-D) is the best choice? (1 mark)

(ii)  Briefly explain your reasoning for your choice (2 marks)

  When comparing the metabolism of glucose in bacterial and mammalian cells:

A.  Glycolysis is highly conserved; the citric acid cycle and oxidative phosphorylation differs in some bacteria compared with mammalian cells.

B.   Bacteria can only use glucose as an energy source whereas mammalian cells can use alternative energy sources.

C.   Bacteria only use glycolysis for the formation of ATP; they do not possess ATPase and do not use chemiosmosis.

D.   Bacteria do not respire, they only ferment.

(i)   Which response (A-D) is the best choice? (1 mark)

(ii)  Briefly explain your reasoning for your choice (2 marks)

Which one of the following techniques is NOT a good choice for sterilising a product?

A.   Pasteurisation

B.   Dry heat (170°C for 2 hours)

C.   Autoclaving (121°C for 20 minutes)

D.   Ionising radiation

(i)  Which response (A-D) is the best choice? (1 mark)

(ii ) Briefly explain your reasoning for your choice (2 marks)

Which bacterial gene transfer process is most sensitive to extracellular nucleases?

A.   Transduction

B.   Conjugation

C.   Transformation

D.   Recombination

(i)   Which response (A-D) is the best choice? (1 mark)

(ii)  Briefly explain your reasoning for your choice (2 marks)

Some species of Bacteria are susceptible to the antibiotic penicillin whereas Fungi are not. Which one of the following is the best explanation for this?

A.   Fungi do not have a cell wall.

B.   Fungi are structurally different to bacteria, making penicillins ineffective. 

C.   Fungi do not have specialised structures such as flagella.

D.   Fungi are not pathogens and thus antibiotics are not designed to target them.

(i)  Which response (A-D) is the best explanation? (1 mark)

(ii ) Briefly explain your reasoning for your choice (2 marks)

Alanna was cleaning out her pantry and opened a jar of jam to find a strange odour and a white-ish substance growing on top of the jam. Alanna thinks the jam has been contaminated by a bacterium. Which type of extremophile is likely to be the one responsible for the growth on top of the jam? 

A.   Psychrophile

B.   Thermophile

C.   Alkaliphile

D.   Halophile

(i)   Which response (A-D) is the best choice? (1 mark)

(ii)  Briefly explain your reasoning for your choice (2 marks)

Hyperbaric oxygen therapy can be used to increase oxygen concentrations in the tissues of people with certain infections.  Which one of the following types of disease-causing microbes would be targeted with this type of therapy?

A.   Strict aerobes

B.   Facultative anaerobes

C.   Aerotolerant anaerobes

D.   Strict anaerobes

(i)   Which response (A-D) is the best choice? (1 mark)

(ii)  Briefly explain your reasoning for your choice (2 marks)

The genes a bacterium uses to produce the amino acid arginine form part of the arg operon.  In this operon, when arginine binds to the repressor protein, transcription of the structural genes of the arg operon is blocked.  What type of operon is the arg operon?

A.   An inducible operon

B.   A repressible operon

C.   A catabolite operon

D.   The genes are constitutively expressed

 (i)   Which response (A-D) is the best choice? (1 mark)

(ii)  Briefly explain your reasoning for your choice (2 marks)

You are performing a Gram stain on an unknown bacterium.  You proudly show your pink bacilli to your facilitator who sadly shakes her head and says they should have been purple.  Which one of the following is the best explanation for where you went wrong?

A.   You forgot to add the carbol fuschin

B.   You forgot to add the iodine

C.   You skipped the alcohol decolourisation step

D.   You didn’t fix your cells to the slide before staining

(i)   Which response (A-D) is the best choice? (1 mark)

(ii)  Briefly explain your reasoning for your choice (2 marks)

You wish to view a live bacterial cell that contains no natural pigments or fluorophores.  Which one of the following would be the most appropriate microscope for this task?

A.    A bright field microscope

B.    A phase contrast microscope  

C.    A fluorescent microscope

D.    An oil immersion microscope

(i)  Which response (A-D) is the best choice? (1 mark)

(ii ) Briefly explain your reasoning for your choice (2 marks)