prokaryotic cell/viruses

Question 1

what is a prokaryotic cell?

Answer 1

a cell which has no membrane-bound organelles

Question 2

how do prokaryotic cells differ from eukaryotic cells?

Answer 2

• smaller
• smaller ribosomes
• no nucleus - circular strand of DN
• cell wall made of murein (peptidoglycan)
• capsule
• one or more flagella
• one or more plasmid

Question 3

role of capsule

Answer 3

protection by producing mucilaginous slime around wall which helps groups of bacteria stick together for further protection

Question 4

role of plasmids

Answer 4

• used as vectors for genetic engineering

- reproduce independently so useful for antibiotic resistance

Question 5

what is a virus?

Answer 5

an acellular, non-living particle

Question 6

what is a virus composed of?

Answer 6

a core of nucleic acid (DNA/RNA) surrounded by a protein coat called a capsid (sometimes has a lipid layer)
- attachment proteins on outside

Question 7

why do viruses not undergo cell division?

Answer 7

because they are non-living

Question 8

how do viruses duplicate themselves?

Answer 8

• attachment proteins bind to host cell
• inject nucleic acids into cell
• provides instructions for host cell’s metabolic processes to replicate the virus and release the new viruses

Question 9

what is the name of the type of cell division which occurs in prokaryotic cells?

Answer 9

binary fission

Question 10

describe how binary fission works

Answer 10

• cell duplicates its circular DNA and its plasmids which attach themselves to cell membrane
• cell grows which increases distance between DNA (DNA segregation)
• cell wall (septum) forms down middle of cell bisecting it
• two identical daughter cells produced with single copy of circular DNA but variable numbers of plasmids

Question 11

how does Amoeba split in half since it does not have a cell wall?

Answer 11

it develops a cleavage furrow that pinches the cell in half