3.6- PROKARYOTIC CELLS AND VIRUSES

Question 1

What are the two main types of cells?

Answer 1

eukaryotic cells and prokaryotic cells

Question 2

What is the size of eukaryotic cells and what do they have?

Answer 2

larger + have nucleus bounded by nuclear membranes (nuclear envelope)

Question 3

What is the size of prokaryotic cells and what do they not have?

Answer 3

smaller + have no nucleus or nuclear envelope

Question 4

Why do bacteria occur in every habitat in the world?

Answer 4

versatile, adaptable + very successful

Question 5

What is much of the success of bacteria due to?

Answer 5

their small size, normally ranging from 0.1 to 1.0μm in length

Question 6

What is the cellular structure of bacteria like?

Answer 6

relatively simple

Question 7

What do all bacteria possess?

Answer 7

cell wall

Question 8

What is the cell wall of bacteria made up?

Answer 8

murein

Question 9

What is murein?

Answer 9

polymer of polysaccharides + peptides

Question 10

How do many bacteria further protect themselves?

Answer 10

by secreting a capsule of mucilaginous slime around this wall

Question 11

What is within the cell wall of a bacteria?

Answer 11

cell-surface membrane

Question 12

What types of ribosomes are in the cytoplasm of a bacteria cell?

Answer 12

70S ribosomes

Question 13

What is the difference between 70S and 80S ribosomes?

Answer 13

70S smaller

Question 14

What does bacteria store food reserves as? (2)

Answer 14

glycogen granules + oil droplets

Question 15

What is the genetic material in bacteria in the form of?

Answer 15

circular strands of DNA

Question 16

What is a form of genetic material that is separate from smaller circular pieces of DNA?

Answer 16

plasmids

Question 17

What can plasmids do?

Answer 17

reproduce themselves

Question 18

What can plasmids give bacteria?

Answer 18

resistance to harmful chemicals e.g. antibiotics

Question 19

What are plasmids used extensively as?

Answer 19

vectors (carriers of genetic information) in genetic engineering

Question 20

Is DNA associated with proteins in prokaryotic cells?

Answer 20

no

Question 21

Is DNA associated with proteins in eukaryotic cells?

Answer 21

yes- proteins called histones

Question 22

What is the role of the capsule in a bacteria?

Answer 22

protects bacterium from other cells + helps groups of bacteria to stick together for further protection

Question 23

What is the flagellum in bacteria used for?

Answer 23

locomotion (only certain species)

Question 24

How thick is the cell wall of a bacteria?

Answer 24

10-80nm thick

Question 25

What are viruses?

Answer 25

acellular, non-living particles

Question 26

Range of size for viruses

Answer 26

20-300 nm

Question 27

What do viruses contain as genetic material?

Answer 27

nucleic acids such as RNA or DNA

Question 28

Where can viruses multiply only?

Answer 28

inside living host cells

Question 29

Where is the nucleic acid of viruses enclosed within?

Answer 29

within protein coat called capsid

Question 30

Example of virus that that is surrounded by a lipid envelope?

Answer 30

HIV

Question 31

What does the lipid envelope, or if this is not present, capsid, what do they have?

Answer 31

attachment proteins

Question 32

What are the attachment proteins of viruses essential for?

Answer 32

to allow virus to identify + attach to a host cell