Week 7 - Topic 6 -

Question 1

The three domains of life are

Answer 1

Bacteria, Archaea, Eukarya

Question 2

Domain Bacteria and domain Archaea consist of

Answer 2

Unicellular prokaryotes

Question 3

Domain Eukarya: the eukaryotes consist of how many kingdoms? (Name them)

Answer 3

Divided into 4 kingdoms:
– Protists
– Fungi
– Plants
– Animals

Question 4

Domain Bacteria

Answer 4

Bacteria are the most diverse and widespread prokaryotes and are now divided among multiple kingdoms.

Question 5

Domain Archaea

Answer 5

Live in extreme environments, such as salty lakes and boiling hot springs. Domain Archaea includes multiple kingdoms.

Question 6

Domain Eukarya: Protists

Answer 6

Protists are unicellular eukaryotes and some simple multicellular relatives. Scientists are currently debating how to split the protists into several kingdoms.

Question 7

Domain Eukarya: Kingdom Fungi

Answer 7

is defined in part by the nutritional mode of its members, such as this mushroom, which absorb nutrients after decomposing organic material.

Question 8

Domain Eukarya: Kingdom Plantae

Answer 8

consists of multicellular eukaryotes that carry out photosynthesis, the conversion of light energy to food.

Question 9

Domain Eukarya: Kingdom Animalia

Answer 9

consists of multicellular eukaryotes that ingest other organisms.

Question 10

Βasic categories of living organisms

Answer 10

Question 11

Μicro-organisms

Answer 11

Μicroscopic organisms consisting from
either 1 cell (unicellular) or a group of cells (multicellular)

Question 12

Micro-organisms categories:

Answer 12

• Βacteria and Archaea: unicellular prokaryotic microorganisms
• Protists: eukaryotic microorganisms (example: protozoa, algae)
• Fungi: eukaryotic microorganisms (example: yeasts, mushrooms)
• Viruses: non-cellular pathogens

Question 13

Historical evidence for existence of
micro-organisms

Answer 13

• Pasteur (1870): discovered the role of pathogenic bacteria in transmission of infectious diseases.
• Koch (1892): discovered Vibrio cholerae as the pathogen that causes cholera.
• Alexander Fleming (1929): discovered the antibiotic penicillin.
• Infectious disease control due to discovery of antibiotics and vaccination

Question 14

What does “Yersinia pestis bacterium” cause

Answer 14

plague (Black Death)

Question 15

Prokaryotes

Answer 15

• Unicellular micro-organisms.
• Consist of 1 prokaryotic cell.
• Replicate much faster than eukaryotes.
• Smaller in size than eukaryotic cells.
• Can thrive almost everywhere, even under extreme conditions (too acidic, salty, cold, dry or hot for most other organisms).

Question 16

Prokaryotes are divided into 2 domains:

Answer 16

1) Bacteria.
2) Archaea.

Question 17

Domain Bacteria (2 major categories)

Answer 17

1) Εubacteria.
2) Cyanobacteria.

Question 18

Eubacteria

Answer 18

Includes pathogenic bacteria => cause
diseases.

Question 19

Cyanobacteria

Answer 19

• non-pathogenic.
• have chlorophyll and perform photosynthesis.
• produce oxygen.
• live in lakes, oceans, etc…
• role in nitrogen fixation (conversion of nitrogen into ammonia => used by the plants).