3.6 Prokaryotic cells and viruses

Question 1

What is the role of the cell wall in a bacterial cell?

Answer 1

physical barrier that excludes certain substances and protects against mechanical damage and osmotic lysis

Question 2

What is the role of the cell-surface membrane in a prokaryotic cell?

Answer 2

acts as a differentially permeable membrane layer, which controls entry and exit of chemicals

Question 3

What is the role of the circular DNA in a prokaryotic cell?

Answer 3

processes the genetic information for the replication of bacterial cells

Question 4

What is the role of the plasmids in a prokaryotic cell?

Answer 4

possesses genes and may aid the survival of bacteria in adverse conditions

Question 5

Structures inside a generalised bacterial cell? (8)

Answer 5

• cell wall
• capsule
• cell-surface membrane
• circular DNA
• plasmid
• flagellum
• ribosomes
• cytoplasm

Question 6

What are the difference in ribosomes in prokaryotic and eukaryotic cells?

Answer 6

Prokaryotic = 70s (smaller)
Eukaryotic = 80s (larger)

Question 7

What structures are found in viruses? E.g. HIV (6)

Answer 7

• genetic material (RNA)
• reverse transcriptase (enzyme)
• matrix
• lipid envelope
• capsid
• attachment protein