Target: 10 questions in 10 mins

Q1&2. The Hawaiian bobtail squid shown below displays bioluminescence due to Vibrio fischeri bacteria.

 Chris Frazee and Margaret McFall-Ngai
CC BY-SA 4.0

1. Which of the following applies to this scenario?

I. Quorum sensing is used for communication and coordination among bacterial cells
II. Quorum sensing alters gene expression in bacterial cells
III. The relationship between the squid and bacteria is parasitic
  • A. I only
  • B. I and II only
  • C. II and III only
  • D. I, II, and III

2. The image shows quorum sensing in bacteria such as Vibrio fischeri.

Y_tambe
CC BY-SA 3.0
With regards to quorum sensing in Vibrio fischeri bacteria, which description is best?
  • A. As the bacterial population increases, there is positive feedback acting on the production of molecule X
  • B. As the bacterial population increases, there is feedback inhibition of the production of molecule X
  • C. There is negative feedback increasing the production of molecule X
  • D. Population size of bacteria has no effect on production of molecule X

3. Which row shows the correct classification of hormones?

  Steroid  Peptide Amine
A. Oestradiol  Glucagon Antidiuretic hormone (ADH)
B. Testosterone  Progesterone Dopamine
C. Testosterone  Cytokine  Glucagon
D. Oestradiol Insulin Adrenaline/epinephrine
4. Which of the following statements best describes the mechanism of action of steroid hormones?
  • A. They bind to receptors on the cell surface and activate second messenger pathways
  • B. They bind to intracellular receptors and influence gene expression
  • C. They bind to ion channels and alter membrane potential
  • D. They are degraded by enzymes in the extracellular space before reaching their target cells

5. “Production of this category of signaling molecules may involve ribosomes.” For which of the following is this statement true?   

I. Cytokines
II. Calcium ions
III. Hormones
IV. Neurotransmitters
 
  • A. I, III and IV only
  • B. III only 
  • C. II and IV only
  • D. I, II, III and IV

6. In signaling pathways what is usually the correct sequence of events?  

I. Ligand-receptor binding
II. Cellular response
III. Signal transduction
  • A. I → II → III
  • B. I → III → II
  • C. III → II → I
  • D. III → I → II
7. Acetylcholine receptors on postsynaptic neurons can be accurately described as ...
  • A. Ligand gated potassium ion channels
  • B. Voltage gated sodium ion channels
  • C. Ligand gated sodium ion channels
  • D. Protein pumps

8. The image below shows a G protein coupled receptor:

 Opossum58
CC BY-SA 3.0

Which letter shows a hydrophobic region arranged in an alpha helix?
9. What is the primary role of G protein coupled receptors (GPCRs) in cellular signalling?
  • A. To directly phosphorylate proteins in the cell
  • B. To activate nucleotide binding proteins that then trigger various cellular responses
  • C. To transport ions across the plasma membrane
  • D. To act as enzymes that break down signaling molecules
10. Which molecule acts as the second messenger in the action of epinephrine (adrenaline) receptors?
  • A. Calcium ions
  • B. cAMP (cyclic AMP)
  • C. ATP
  • D. GTP