Lecture 1.3 - Introduction to Microbes

Question 1

Is it possible to see individual bacteria with a light microscope?

Answer 1

Yes

Question 2

In which 3 ways are viruses classified?

Answer 2

DNA vs RNA
Single vs double stranded
Enveloped vs non-enveloped

Question 3

What is a bacteriophage?

Answer 3

A virus that infects a bacteria and uses it to multiply

Question 4

What is significant about viral use of bacteria to multiply?

Answer 4

Allows transfer of bacterial DNA, including genes for different toxins and antimicrobial resistance

Question 5

What is the name given to round bacteria?

Answer 5

Cocci

Question 6

What are rod-shaped bacteria known as?

Answer 6

Bacilli

Question 7

What two arrangements may cocci be found in?

Answer 7

• Clusters

- Chains

Question 8

What are spores?

Answer 8

Coated particles formed by obligate anaerobes which allow them to withstand oxygen

Question 9

What are the two main classifications of fungi?

Answer 9

Yeasts and moulds

Question 10

Are fungi prokaryotic?

Answer 10

No - eukaryotic

Question 11

Which type of fungi is unicellular?

Answer 11

Yeasts

Question 12

Are moulds single-cellular?

Answer 12

No - multicellular

Question 13

What are the two major types of parasite?

How do they differ?

Answer 13

Protozoa - single-celled

Helminths/worms - multicellular

Question 14

What colour do gram-negative bacteria appear?

Answer 14

Red

Think about a bank statement - in the negative = red!

Question 15

A gram-stained bacterium appears blue. Is it gram positive or gram negative?

Answer 15

Gram positive

Question 16

Describe the Gram staining process

Answer 16

1) Positively charged crystal violet binds to -ve cell components
2) Iodine forms complexes with the crystal violet
3) Acetone/methanol extracts complexes through gram -ve wall, removing blue stain. Remains if gram +ve.
4) Gram -ve stained red using safrinin

Question 17

Is it possible to view viruses with a light microscope?

Answer 17

No - need an electron microscope