prokaryotes

Question 1

characteristics of prokaryotes

Answer 1

• lack a nucleus surrounded by a nuclear envelope
• have a single circular molecule of DNA, associated with non-histone proteins, in a region called the nucleoid
• lack membrane-bounded organelles
  o EXCEPT CYNOBACTERIA AND PURPLE BACTERIA; PHOTOSYN
  have ribosomes
  unicellular

Question 2

cell walls/gram +/ -

Answer 2

• archaea do not have cell walls
• responsible for the mechanical strength of the wall—peptidoglycan
• gram +: has peptidoglycan
• gram - : two layers; peptidoglycan and lipopolysaccharides

Question 3

bacillus

Answer 3

rod form of bacteria

Question 4

binary fission

Answer 4

grows exponentially; divides in 2

Question 5

transformation

Answer 5

o occurs when a prokaryote takes up free, or naked, DNA from the environment. The free DNA may have been released by an organism that died.

Question 6

transduction

Answer 6

o occurs when viruses that attack bacteria—viruses known as bacteriophages—bring with them DNA they have acquired from their previous host

Question 7

conjugation

Answer 7

o DNA is transferred from one bacterium to another. After the donor cell pulls itself close to the recipient using a structure called a pilus, DNA is transferred between cells. In most cases, this DNA is in the form of a plasmid
o Plasmid carry genes that have a selective advantage

Question 8

endospores

Answer 8

• dormant resting cells, process, called sporulation
  o occurs when a population of cells begins to use up its food supply
  o resistant to heat, radiation, and chemical disinfectant

Question 9

photoautotroph

Answer 9

sunlight energy source + CO2 carbon source

Question 10

chemoautotroph

Answer 10

inorganic energy source + CO2 (inorganic carbon source)

Question 11

photoheterotroph

Answer 11

sunlight energy source + organic carbon source

Question 12

chemoheterotroph

Answer 12

organic energy source +organic carbon source

Question 13

aerobes

Answer 13

require oxygen for respiration

Question 14

anaerobes

Answer 14

lack an aerobic pathway and there fore cannot use oxygen as a terminal electron acceptor
o generate energy by anaerobic respiration—in which inorganic molecules such as sulfates are the terminal electron acceptor—or by fermentation.

Question 15

strict anaerobes

Answer 15

killed by oxygen

Question 16

facultative anaerobes

Answer 16

can grow in the presence or absence of oxygen

Question 17

psychophiles

Answer 17

cold-loving

Question 18

thermophiles and extreme thermophiles

Answer 18

heat loving (80, >100)

Question 19

commercial use

Answer 19

• Bioremediation—use organisms to remove pollutants from water, air, and soil
• Antibiotics
• Fermentation of lactose
• Drugs and vaccines

Question 20

cyanobacteria

Answer 20

• one of the major evolutionary lines of Bacteria
• chlorophyll a and carotenoids and other pigments called phycobilin
  o blue and green algae
• parallel membranes like thylakoids and are the ancestor of chloroplast
• Fix nitrogen, converting nitrogen gas into ammonium
  o Done by heterocyst
  o In anaerobic condition
• Resist spores called akinetes, resistant to heat
• Produce cyanotoxins when they bloom
  o Neurotoxins, hepatotoxins
  o Kills fish b/c O2 depletion
  o Bloom b/c of high levels of phosphorus
• Found in sponges, amoebas, and vascular plants

Question 21

lichens

Answer 21

o Are symbiotic associations b/w one or two fungus and green algae or cyanobacteria
 Mutualism—b/c fungus gets food b/c cyanobacteria does photosyn and cyano has a protected home b/c of fungus

Question 22

stromatolites

Answer 22

• produced when colonies of cyanobacteria bind calcium-rich sediments.
  o In shallow pools in hot, dry climates

Question 23

cyanobacteria photosynthesis

Answer 23

CO2 + 2H2O CH2O +H2O + O2

Question 24

purple and green bacteria photosynthesis and live in…

Answer 24

CO2 + 2H2S CH2O+ H2O + 2S
 Live in decaying organic matter

Question 25

extreme halophiles

Answer 25

salty environ
o heterotrophs that obtain their energy from the oxidation of organic compounds and require oxygen

Question 26

extreme thermophiles

Answer 26

100 deg water with a lot of sulfur and minimal oxygen
o metabolize sulfur in some way
o strict anaerobes w/a few exceptions

Question 27

methanogens

Answer 27

produce methane (CH4)
live in strict anaerobic environ

Question 28

parasites

Answer 28

• symbionts that are harmful to their hosts.

Question 29

viruses

Answer 29

b/w living and non living
* contain genetic material (RNA or DNA)
* Cannot reproduce on their own, must infect cell
* Host can be animal, plant, bacterium, etc
* Affect plants leaves stems roots and flowers
o Transported by a vector or enter through a wound

Question 30

how to control viruses

Answer 30

 Chem or bio ctrl over vector
 Grow resistant varieties
 Plant virus free material
 Exclusion—prevent it in the first place

Question 31

cocci

Answer 31

berry form of bacteria

Question 32

spirochetes

Answer 32

bristles/hair form of bacteria