chap 27

Question 1

Identify the differences between Bacteria, Archaea, and Eukarya, and the evolutionary relationships between the 3 groups

11

5 characteristics

Answer 1

Prokaryotes - Bacteria and Archaea domains
Eukaryotes - Eukaryra domain (animals, plants, fungi, protists)

Archaea is more closely related to eukaryra.

Prokaryotic cells are wayyy smaller.

Archaea and eukaryotic cells similarities:
- cytoplasm
- histones (proteins in dna repli)
- ribosomes.
- NO nucleus
- circular DNA

Many Archaea are extremophiles

Some Bacterias are extremophiles. more are not.

Bacterias are extremely diverse.

Mitochondria and plastids orginated from bacteria (endosymbiosis).

Horizontal gene transfer = bact + arch
- Transduction (viral),
- transformation (dna from disintegrated cell),
- conjugation (mating).

-Prokaryotes produce asexually only

Question 2

Explain the ecological roles of prokaryotes

3

Answer 2

-Many fix nitrogen to be used by producers

-Vastly diverse, can be pathogens, producers, decomposers, symbionts, etc.

-Produce organic carbon, may produce up to 50% of the atmospheric oxygen

Question 3

Explain the ecological roles of decomposers

Answer 3

Releases CO2, breaks down carbon into minerals to be released back into the environment.
important for global carbon cycle.

Question 4

Explain the ecological roles of producers

Answer 4

-Convert CO2 into O2
-Main food source to life

Question 5

Explain the ecological roles of nitrogen fixers

Answer 5

Bacteria convert atmospheric N2 into usable compounds (nitrates, ammonium) for plants to be able to metabolize

Question 6

Explain the ecological roles of pathogens

Answer 6

regulate populations and ecosystems

Question 7

Explain the ecological roles of various symbioses

2

Answer 7

1. Mutualistic bacteria - help each other with nutrients
2. Pathogenic bacteria - Cause illness –> decreases abundant pop.

Question 8

Horizontal gene transfer

3

Answer 8

Transformation, transduction, and conjugation

it is used in 80% of the bac and arch

allows diff species of bac and arch to become immune or pathogenic from the DNA of another.

Question 9

importance of horizontal gene transfer in the evolution eukaryotic groups

Answer 9

the endosymbiosis of mitochondria and plastids is a form of horizontal gene transfer from bacteria to eukaryotes that impacted eukaryotes.

Question 10

coccus

Answer 10

spherical shape bac

Question 11

bacillus

Answer 11

rod-shaped bac

Question 12

spirillus

Answer 12

spiral shape bac

Question 13

vibros

Answer 13

comma-shaped bac

Question 14

cell wall types

Answer 14

gram + and gram -

Question 15

gram +

Answer 15

high amount of peptidoglycan and only an inner cell membrane
stains purple
thick wall.

Question 16

gram -

Answer 16

thin peptidoglycan wall. have a plasma membrane anddd a lipopolaysaccharide-rich outer envelope.
turn pink

Question 17

photoautotroph

e source, c source

Answer 17

e source - light
c source - co2

Question 18

chemoautotroph

Answer 18

e source - inorganic compounds
c source - co2

Question 19

photoheterotroph

Answer 19

e source - light
c source - organic compounds

Question 20

chemoheterotroph

Answer 20

e source - organic compounds
c source - organic compounds

Question 21

obligated aerobes

Answer 21

need O2

Question 22

facultative aerobes

Answer 22

can use O2 or not

Question 23

obligate anaerobes

Answer 23

cannot tolerate O2 – can die from it

Question 24

aerotolerant anaerobes

Answer 24

don’t use O2 but cannot die from it

Question 25

halophile

Answer 25

archaea extremophile tolerates salty env.

Question 26

extremophile

Answer 26

organism that lives in extreme envi.

most are archaeas, some are bacs.

Question 27

thermophile

Answer 27

archaea extremophile that like high heat

Question 28

methanogen

Answer 28

archaea extremophile that generates methane as a bioproduct

Question 29

transformation

Answer 29

cell picks DNA from its surroundings and incorporate it as its own

Question 30

transduction

Answer 30

bacterial viruses cary prokaryotic genes from one host to another cell.

Question 31

conjugation

Answer 31

DNA is transferred between two prokaryotic cells via temporary joining with pili.

Question 32

commensalism

Answer 32

one species benefits and the other is unaffected