3.2.1.2 Structure Of Prokaryotic Cells

Question 1

What are the features of a prokaryotic cell?

Answer 1

-much smaller than eukaryotic cells
-do not have a nucleus
-have no membrane-bound organelles
-murein cell wall
-smaller 70s ribosomes

Question 2

What are the four structures specific to a bacterium?

Answer 2

Slime capsule
Flagellum
Single loop circular DNA
Plasmid

Question 3

What is the function of the slime capsule?

Answer 3

Helps to protect the bacterium from dessciation (drying out) and from attacks from the host’s immune system.

Question 4

What is single-loop circular DNA?

Answer 4

The DNA store in prokaryotes as there is no nucleus. It is free in the cytoplasm and not bound by a protein

Question 5

What is the flagellum?

Answer 5

A long, tail-like structure that rotates to enable movement

Question 6

What are plasmids?

Answer 6

Small loops of extra DNA that carry genes that can be passed between prokaryotes eg. Antibiotic resistance in bacteria

Question 7

What are the features of a virus?

Answer 7

-acellular (not a cell)
-non-living as they cannot reproduce on their own, so reproduce by invading other living cells
-much smaller than eukaryotes ands prokaryotes

Question 8

What are the 3 structures of a virus?

Answer 8

Genetic material (DNA or RNA)
Attachment proteins
Capsid (protein coat)

Question 9

Do bacteria have RNA?

Answer 9

Yes- they have both DNA and RNA eg. mRNA and tRNA

Question 10

Describe how bacteria divide- exam q

Answer 10

By binary fission
Replication of circular DNA
Division of cytoplasm to produce 2 daughter cells
Each with a single copy of circular DNA