Week 3 Bacterial Physiology

Question 1

a method of asexual reproduction involving halving of the nucleus and cytoplasm of the cell followed by the development of each half into a new individual cell; process is quick and produces multiple generations of a single bacterial cell within a brief period of time

Answer 1

binary fission

Question 2

a visible group of bacteria growing on a solid medium, presumably arising from a single microorganism

Answer 2

bacterial colony

Question 3

self-nourishing bacteria; able to grow without the presence of organic compounds; obtain nutrition from carbon in carbon dioxide

Answer 3

autotrophic bacteria

Question 4

organisms that must obtain their nourishment from complex organic matter; several different types with varying requirements

Answer 4

heterotrophic bacteria

Question 5

an organism that can survive only on dead or decaying organic matter

Answer 5

strict (obligate) saprophyte

Question 6

an organism that is completely dependent on its living host for survival

Answer 6

strict (obligate) parasite

Question 7

an organism that prefers living organic matter as a source of nutrition but can adapt to the use of dead organic matter under certain conditions

Answer 7

facultative saprophyte

Question 8

an organism that prefers dead organic matter as a source of nutrition but can adapt to the use of living organic matter under certain conditions

Answer 8

facultative parasite

Question 9

a microbe that can live only in the presence of free oxygen

Answer 9

strict (obligate) aerobe

Question 10

a microbe that can survive only in the absence of free oxygen

Answer 10

strict (obligate) anaerobe

Question 11

requiring very little free oxygen; as found with certain bacteria

Answer 11

microaerophilic

Question 12

a microorganism that prefers an environment devoid of oxygen but has adapted so that it can live and grow in the presence of oxygen

Answer 12

facultative aerobe

Question 13

an organism that prefers the presence of oxygen but is capable of living and growing in its absence

Answer 13

facultative anaerobe

Question 14

requirements for bacterial growth

Answer 14

food, oxygen, moisture, temperature, pH, light, osmotic pressure

Question 15

temperature at which organisms grow best

Answer 15

optimum temperature

Question 16

temperature below which bacterial growth will not take place

Answer 16

minimum temperature

Question 17

temperature above which bacterial growth will not take place

Answer 17

maximum temperature

Question 18

bacteria that prefer cold, thriving at temperatures between 0°C and 25°C

Answer 18

psychrophile

Question 19

bacteria that prefer moderate temperatures and develop best at temperatures between 25°C and 40°C

Answer 19

mesophile

Question 20

bacteria that thrive best at high temperatures, between 40°C and 70°C

Answer 20

thermophile

Question 21

pressure that develops when two solutions of different concentrations are separated by a semipermeable membrane

Answer 21

osmotic pressure

Question 22

a relationship in which organisms of different species live in close nutritional relationships

Answer 22

symbiosis

Question 23

a relationship in which organisms of two different species live in close association to the mutual benefit of each

Answer 23

mutualism

Question 24

the symbiotic relationship of two organisms of different species in which one gains some benefit such as protection or nourishment, and the other is not harmed or benefited

Answer 24

commensalism

Question 25

a symbiotic relationship between two organisms in which one is harmed and the other benefits

Answer 25

parasitism

Question 26

organisms that are free-living; relationships are not required for survival

Answer 26

non-symbiotic

Question 27

the relationship between two or more microorganisms of different species in which they grow better together but can survive alone

Answer 27

synergism

Question 28

mutual opposition or contrary action; the inhibition of one microorganism by another

Answer 28

antagonism