Microbial Growth and Biofilms Quiz

Select the physical factors below that can affect microbial growth.

• Temperature

• Radiation (visible light, UV, gamma)

• Barometric pressure

• Extreme drying/dehydration

Archaea, as a group, are not pathogens. This is because _______.

• they evolved without mammals

• mammals evolved special defenses against them

• mammalian hosts do not meet their environmental requirements

• they are outcompeted by natural flora

• None of the choices are correct

Cultures of a bacterial species were incubated out on the incubator shelf, in an anaerobic jar, and in a candle jar. After incubation, there was moderate growth of cultures in the candle and anaerobic jars, but heavy growth of the culture on the incubator shelf. This species is a(n) _______.

• obligate aerobe

• obligate anaerobe

• facultative anaerobe

• microaerophile

• capnophile

Tags

NGSS.HS-LS2-3

The toxic superoxide ion is converted to harmless oxygen by two enzymes, _______.

• catalase and hydrogen peroxidases

• superoxide dismutase and hydrogen peroxidases

• superoxide dismutase and catalase

• catalase and oxidase

• superoxide dismutase and oxidase

An organism that respires using oxygen when it is present but can switch to an alternative anaerobic pathways when it is absent is a(n) _______.

• aerotolerant anaerobe

• obligate aerobe

• facultative anaerobe

• microaerophile

• obligate anaerobe

Tags

NGSS.HS-LS2-3

An organism that cannot grow without oxygen is a(n) _______.

• aerotolerant anaerobe

• obligate aerobe

• facultative anaerobe

• microaerophile

• obligate anaerobe

Tags

NGSS.HS-LS2-3

A halophile would grow best in _______.

• acid pools

• freshwater ponds

• hot geyser springs

• arid, desert soil

• salt lakes

The E. coli that normally live in the human large intestines and produce vitamin K for the body to use would best be termed a _______ relationship.

• parasitic

• saprobic

• commensal

• mutualistic

• None of the choices are correct.

The phase of the bacterial growth curve in which the rate of cell division equals the rate of cell death is the _______.

• lag phase

• log phase

• stationary phase

• death phase

• telophase

The phase of the bacterial growth curve that shows the maximum rate of cell division is the _______.

• lag phase

• exponential (log) phase

• stationary phase

• death phase

• prophase