Prokaryotic Cells and Viruses

Question 1

What is the difference between Eukaryotic and Prokaryotic cells?

Answer 1

Eukaryotes are larger, and prokaryotes have no nucleus or nuclear envelope, whereas eukaryotes do.

Question 2

Why are bacteria successful?

Answer 2

They are versatile and adaptable and are of a very small size (0.1-10 um)

Question 3

What is the bacterial cell wall made up of?

Answer 3

Made up of murein, which is a polymer of polysaccharides and peptides.

Question 4

How do bacteria protect themselves?

Answer 4

They secrete a capsule of mucilaginous slime around their cell wall.

Question 5

Which ribosomes do bacteria contain?

Answer 5

70s (smaller) which synthesise proteins.

Question 6

What do bacteria store food reserves as?

Answer 6

Glycogen granules and oil droplets?

Question 7

What form is the genetic material of bacteria in?

Answer 7

The form of a circular strand of DNA. Separate to this are smaller circular pieces of DNA called Plasmids.

Question 8

What is the importance of plasmids for bacteria cells?

Answer 8

They can reproduce themselves independently and may give the bacterium resistance to harmful chemicals, such as antibiotics. Plasmids are extensively used as carriers of genetic information in genetic engineering.

Question 9

What is the role of the bacterial cell wall?

Answer 9

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

Question 10

What Is the role of the bacterial capsule?

Answer 10

Protects bacterium from other cells and helps groups of bacteria to stick together for further protection.

Question 11

What is the role of the bacterial cell-surface membrane?

Answer 11

Act as a differentially permeable layer, controlling entry and exit of chemicals.

Question 12

What is the role of bacterial circular DNA?

Answer 12

Possesses genetic information for the replication of bacterial cells.

Question 13

What Is the role of the bacterial plasmid?

Answer 13

Possesses genes that may aid the survival of bacteria in adverse conditions. E.g. It produces enzymes that break down antibiotics.

Question 14

What are viruses?

Answer 14

Viruses are acellular, non-living particles that are smaller than bacteria.

Question 15

What do viruses contain but not use to multiply?

Answer 15

Nucleic acids such as DNA and RNA as genetic material, but can only multiply in living host cells.

Question 16

What is the nucleic acid enclosed in?

Answer 16

A protein coat called the capsid.

Question 17

What are some viruses further surrounded by to allow the virus to identify and attach to a host cell?

Answer 17

A lipid envelope, e.g. HIV, or if this is not present, the capsid have attachment proteins.