The Microbial Planet

Question 1

What is the approximate age of the Earth?

Answer 1

4.6 billion years

Question 2

When did single-celled microorganisms first appear on Earth?

Answer 2

Approximately 3.7 billion years ago

Question 3

What are stromatolites?

Answer 3

Organo-sedimentary structures produced by sediment trapping, binding or precipitation due to microbial activity

Question 4

Which microorganisms primarily produce stromatolites?

Answer 4

Cyanobacteria

Question 5

What major atmospheric change did ancient microbial photosynthesis contribute to?

Answer 5

Increased oxygen levels in the atmosphere

Question 6

What is the historical classification of life into kingdoms based on?

Answer 6

Morphology and nutrition

Question 7

What is the term for the analysis of gene or amino acid sequences to determine evolutionary relatedness?

Answer 7

Phylogenetics

Question 8

Who presented the universal tree of life using ribosomal RNA gene sequences?

Answer 8

Carl Woese

Question 9

What are the three domains of life?

Answer 9

• Bacteria
• Archaea
• Eukaryotes

Question 10

Which domains of life are distinct from one another?

Answer 10

Bacteria and Archaea

Question 11

What is the estimated total number of prokaryotes on Earth?

Answer 11

4 - 6 x 10^30

Question 12

True or False: Microorganisms are the unseen majority in terms of diversity and number.

Answer 12

True

Question 13

What does the term ‘biofilm’ refer to?

Answer 13

A community of microorganisms attached to a surface

Question 14

List some areas impacted by microbiology.

Answer 14

• Health
• Food
• Environment
• Energy
• Biotechnology
• Agriculture
• Climate & Global Climate Change

Question 15

What are probiotics?

Answer 15

Friendly microorganisms that can provide health benefits

Question 16

What is MRSA?

Answer 16

Methicillin-resistant Staphylococcus aureus, a strain resistant to multiple antibiotics

Question 17

What is cholera caused by?

Answer 17

Ingesting water or food contaminated with Vibrio cholera

Question 18

Fill in the blank: The method to prevent microbial spoilage of food is called _______.

Answer 18

Food preservation

Question 19

Name some methods of food preservation.

Answer 19

• Canning
• Freezing
• Pasteurization
• Pickling
• Radiation
• Chemical

Question 20

What role do soil microorganisms play in agriculture?

Answer 20

They mineralize organic matter and cycle essential nutrients

Question 21

What is the significance of legumes in relation to nitrogen?

Answer 21

They have symbiotic bacteria that fix atmospheric nitrogen into a usable form

Question 22

How do ruminants benefit from microorganisms?

Answer 22

Microorganisms in their rumen digest cellulose and produce essential nutrients

Question 23

What is bioremediation?

Answer 23

The use of microorganisms to decontaminate affected environments

Question 24

What are the three strategies of bioremediation?

Answer 24

• Bioattenuation
• Biostimulation
• Bioaugmentation

Question 25

What is the primary productivity percentage attributed to cyanobacteria in the ocean?

Answer 25

50%

Question 26

What types of products can emerging biotechnology produce?

Answer 26

• Enzymes
• Engineered proteins
• Vaccines
• Pharmaceuticals
• Biosensors

Question 27

What is synthetic biology?

Answer 27

An approach combining engineering and microbiology to design cells for specific functions

Question 28

What is the world’s first synthetic organism?

Answer 28

Mycoplasma mycoides

Question 29

What environmental problem are plastic-eating bacteria designed to address?

Answer 29

Plastic waste pollution