III. A - Virology | 5. Bacteriophages and subviral agents

Question 1

I. Subviral agents
1. What are the 2 sub viral agents?

Answer 1

1. Viroids
2. Prions

Question 2

I. Subviral agents
2. What are the features of viroids?

Answer 2

• Smallers known pathogens – only 120 to 475 nucleotides (Humans: approx. 3 200 000 000 nucleotides)
• Has only naked RNA - no protein shell – difference from viruses
• Only infects flowering plants – economical importance for humans

Question 3

I. Subviral agents
3. What are the features of prions?

Answer 3

• Infectios agents only consisting of proteins
• Misfolded proteins that force their conformation on proteins of the host
• induce abnormal folding of specific normal cellular proteins called prion proteins
• All cause degenerative disorders of the brain
• Human prion diseases are rare
• eg. Kuru, Creutzfeldt–Jakob disease (CJD)

Question 4

II. Bacteriophages
1. What are Bacteriophages?

Answer 4

Viruses that infect bacteria

Question 5

II. Bacteriophages
2. What is the structure of bacteriophage?

Answer 5

Question 6

II. Bacteriophages
3. How do bacteriophages work?

Answer 6

• They can transmit DNA from one bacterium to another
  = Transduction
  => Spread of antibiotic resistance and virulence genes among bacteria

Question 7

II. Bacteriophages
4. What are the applications of bacteriophages?

Answer 7