Topic 1.2 - Prokaryotic cells

Question 1

What do prokaryotes lack that eukaryotes present ?

Answer 1

A nucleus

Question 2

Which structure do prokaryotes share ?

Answer 2

A single, circular DNA molecule (genophore)
A peptidoglycan cell wall and 70S ribosomes

Question 3

What may prokaryote cells contain ?

Answer 3

Pili (for attachment or bacterial conjugation)
Flagella (a long whip-like tail for movement)
Plasmids (autonomous DNA molecules)

Question 4

How is the DNA in a prokaryote ?

Answer 4

It is naked and circular without introns

Question 5

Give the main features on which prokaryotic and eukaryotic cells differ

Answer 5

DNA (composition and structure)
Organelles (types present and sizes)
Reproduction (mode of cell division)
Average Size (exceptions may exist)

Question 6

What type of ribosomes do prokaryotes contain ?

Answer 6

70s ribosomes

Question 7

How do prokaryotes reproduce and what is the result of that reproduction ?

Answer 7

They reproduce via binary fission which results in a single chromosome

Question 8

Which are smaller, prokaryotes or eukaryotes ?

Answer 8

Prokaryotes are smaller (1-5 micrometers)
Eukaryotes (10-100 micrometers)

Question 9

Describe binary fissions in steps

Answer 9

The circular DNA is copied
The DNA loops attach to the membrane
The cell elongates, separating the loops
Cytokinesis occurs to form two cells