Chapter 7 Multiple Choice Questions Flashcards
An organic nutrient essential to an organism’s metabolism that cannot be synthesized itself is termed a/an:
a. tace element b. micronutrient c. growth factor d. essential nutrient
c. growth factor
The source of the necessary elements of life is:
a. an inorganic environmental reservoir b. the sun c. rocks d. the air
a. an inorganic environmental reservoir
An organism that can synthesize all its required organic components from CO2 using energy from the sun is a:
a. photoautotroph b. photoheterotroph c. chemoautotroph d. chemoheterotroph
a. photoautotroph
An obligate halophile requires high:
a. pH b. temperature c. salt d. pressure
c. salt
Chemoautotrophs can survive on ____ alone.
a. minerals b. CO2 c. minerals and CO2 d. methane
c. minerals and CO2
A pathogen would most accurately be describes as a:
a. parasite b. commensal c. saprobe d. symbiont
a. parasite
A substance that would be moved by passive transport is:
a. sugar b. water c. amino acids d. food detritus
b. water
A cell exposed to a hypertonic environment will ___ by osmosis
a. gain water b. lose water c. neither gain nor lose water d. burst
b. lose water
Active transport of a substance across a membrane requires:
a. a gradient b. the expenditure of ATP c. water d. diffusion
b. the expenditure of ATP
Environmental factors such as temperature and pH exert their effect on the ____ of microbial cells
a. membranes b. DNA c. enzymes d. cell wall
c. enzymes
Psychrophiles would be expected to grow:
a. in hot springs b. on the human body c. at refrigeration temperatures d. at low pH
c. at refrigeration temperatures
Superoxide ion is toxic to strict anaerobes because they lack:
a. catalase b. peroxidase c. dismutase d. oxidase
c. dismutase
The time required fora cell to undergo binary fission is called the:
a. exponential growth rate b. growth cure c. generation time d. lag period
c. generation time
In a viable plate count, each ___ represents a ___ from the sample population.
a. cell, colony b. colony, cell c. hour, generation d. cell, generation
b. colony, cell
During the phase, the rate of new cells added to the ____ population has slowed down.
a. stationary b. death c. lag d. exponential growth
a. stationary
