Microorganism Classification

Question 1

Size of microorganisms (order and actual size)

Answer 1

Viruses: 0.03-0.3 micrometers
Bacteria: 0.1-10 micrometers
Fungi/Parasites (Protozoa): 4-40 micrometers

Question 2

Bacteria:

• type of organism
• # cells
• important feature
• DNA?
• 2 features they don’t have?
• division?

Answer 2

• prokaryote
• unicellular
• cell wall (peptidoglycan)
• circular chromosome
• membrane-bound organelles; nucleus
• binary fission

Question 3

Bacteria classification (3 ways)

Answer 3

1) gram-positive or gram-negative
2) microscopic morphology
3) aerobic or anaerobic

Question 4

Viruses

• type of organism
• # cells
• components
• what do they require to replicate?
• how do they replicate?
• classification

Answer 4

• not one (neither prokaryotic nor eukaryotic cause they’re not alive)
• acellular (none!)
• DNA or RNA core with protein coat (capsid); sometimes has an envelope (from host cell membrane)
• host cells
• uses host cell’s machinery to replicate
• classified by genetic information: DNA or RNA. Sub-divided by single-stranded/double-stranded/segmented nucleic acid; presence or absence of envelope, and shape of capsid (icosahedral (20 faces); helical; complex)
• DNA vs RNA viruses:
  –> there are not very many DNA viruses, and the rest are RNA viruses. DNA:
  – Hep B (IMPORTANT)
  – Herpesvirus (IMPORTANT)
  – Adenovirus
  – Parvovirus B19
  – Poxviruses
  RNA:
• HIV
• Hep A, C, E, G
• Influenza A, B
• Rotavirus
• Norovirus
• West Nile Virus
• Respiratory Syncytial Virus

Question 5

Fungi

• type of organism
• # cells
• important characteristic
• reproduction?

Answer 5

• Eukaryote
• unicellular or multicellular
• rigid cell wall made of chitin, mannan, and glucan
• sexually or asexually

Question 6

Fungal Classification

Answer 6

• yeast or filamentous fungi (moulds)

Question 7

Yeast

• # cells
• shape of cells
• size
• division?
• what does it look like on culture?

Answer 7

• single cells
• ovoid/spherical
• small, almost like bacteria, different sizes (not identical)
• budding
• waxy appearance

Question 8

Filamentous Fungi (mould)

• # cells
• how does it grow?

Answer 8

• multicellular
• microscopic, branching, threadlike filaments known as mycelium
• mycelium filaments grow up (fuzz on mould) and down into the agar

Question 9

Parasites

• type of organism
• # cells
• what’s special?
• classification?

Answer 9

• eukaryotic
• unicellular or multicellular
• live within or upon another organism
• protozoa and helminths

Question 10

Protozoa

• # cells
• feature
• reproduction
• categories
• divided by?

Answer 10

• unicellular
• cell membrane
• asexually or sexually
• amoebae, ciliates, flagellates, coccidia, microsporidia, sporozoa
• typical site of infection: intestinal, blood, tissue, other

Question 11

Helminths (worms)

• # cells
• reproduction
• categories
• divided by?

Answer 11

• multicellular
• sexual
• nematodes (round worms), cestodes (flat worms), trematodes (flukes)
• typical site of infection: intestinal, blood, tissue, other

Question 12

Summary Slide (4 types microorganisms, divisions)

Answer 12

1. Viruses - 0.03-0.3 micrometers
 (DNA vs RNA)
2. Bacteria - 0.1-10 micrometers
- gram + or -
- shape: cocci or bacilli
- anaerobic vs aerobic
3. Fungi - 4-40 micrometers
- yeast or filamentous fungi (mould)
4. Parasites
- protozoa or helminths - 4-40 micrometers