Chapter 25 & 27

Question 1

The Diversity of Life

Answer 1

• early taxonomists: plants or animals
• later 5 kingdoms recognized:
  1. Monera (prokaryotes)
  2. Protista
  3. Plantae
  4. Fungi
  5. Animalia

Question 2

The 3 Current Domains

Answer 2

1. Bacteria
2. Archaea
3. Eukarya

Question 3

Bacteria and Archaea are Prokaryotic

Answer 3

This is amazing because:

• they make up some of the most abundant organisms on the planet
• live in environments that are too hostile for other forms of life
• they also exist in every other “normal” habitat where life is found ex: places that would be toxic (extreme pH, heavy metal pollution)
• Bacterias have been found 2km below the ground
• Bacterias are responsible for 50% of human disease
• Essential for eukaryotic survival and ancestors to some eukaryotic organelles

Question 4

Prokaryotic Diversity

Answer 4

Major Nutritional Modes:

1. AUTOTROPH:
   - Phototroph
   - Chemoautotroph
2. HETEROTROPH
   - Photoheterotroph
   - Chemoheterotroph
   * SEE NOTES*

Question 5

Structure and Function

Answer 5

Structural and functional adaptations contribute to prokaryotic success

• individual cells (cocus, bacillus, success)
• temporary or permanent aggregates/colonies
• simple multicellular forms division of labour

Question 6

Cell Wall

Answer 6

Maintains shape, protects cell, prevents bursting in hypotonic environment

Question 7

Capsule

Answer 7

Outside cell wall

• polysaccharides or proteins
• protein from host
• attachment: substrate and colony formation

Question 8

Fimbrae and Pili

Answer 8

“Hair like” appendages for attachment

Question 9

Endosphere Formation

Answer 9

-“waiting for environment to change”
-chromosome duplicated
-encased with essential cellular components (enzymes etc.)
-water removed (halting metabolism)
-lysis releases endospore
MOBILITY:
-directed motion (taxis)
-mechanisms (gliding and flagella)

Question 10

Flagella

Answer 10

Over surface or concentrated at one or both ends

Question 11

Internal Organization

Answer 11

• no membrane-bound organelles
• plasma membrane (some have internal membranes to increase surface area for metabolic activity and exchange with the environment

Question 12

Prokaryotic Genetics

Answer 12

• small and circular
• no nucleus; nucleotide region
• some have plasmids
• three factors contribute to diversity:
  1. rapid reproduction
  2. mutation
  3. genetic recombination

Question 13

Prokaryotic reproduction

Answer 13

• binary fission

- rapid

Question 14

Mutation

Answer 14

Source of most generation-to-generation variation

• 1 mutation in each gene every 10 million cell divisions
• one human = 20 billion new E. coli per day
• 2000 mutations per game every day in a single human

Question 15

Genetic Recombination (3)

Answer 15

1. Transformation
2. Transduction
3. Conjugation

Question 16

Transformation

Answer 16

Uptake of naked foreign DNA from the environment

Question 17

Transduction

Answer 17

Viruses that infect bacteria transfer DNA from one host to another

Question 18

Conjugation

Answer 18

• Direct transfer of DNA from one bacterium to another
• Requires F Factor (plasmid or chromosomal) F+ is a donor, F- is recipient
• Sex pili attach F+ to F-
• F+ condition is heritable