If cells are grown in media containing amino acids labeled with radioactive nitrogen, most of radioactivity will be found in the cells

DNA and proteins

Pathogenic bacteria isolated from the respiratory or intestinal tracts of human are

capnophiles that grew best in carbon dioxide incubators.

The introductory biosafety level in labs is

BSL 1

The biosafety level working with potentially airborne pathogens is

BSL 3

Which of the following added to a culture medium will neutralize acids?

buffers

Salts and sugars work to preserve foods by creating a

hypertonic enviroment

The term aerotolerante anaerobe refers

It does not use oxygen but tolerates it

Which the following is advantage of the standard plate count?

determines the number of viable cells

Which of the following is an advantage of the direct microscopic count

requires no incubation time

Most bacteria reproduce by

binary fusion

Most bacteria grow best at PH

PH 7

Most fungi grow best at PH

PH 5

A culture medium on which only gram-positive grow and a yellow halo surrounds S. aureus colonies is called

Selective and differential medium

A culture medium consisting of agar, peptone and beef heart is a

complex medium

During which growth phase will gram positive bacteria be most susceptible to penicillin

log phase

The source of nutrients in nutrient agar is

peptone and beef extract

Patients with indwelling catheters are susceptible to infections because

biofilms develop on catheters

Pure cultures can easily be obtained on streak plates, even if the desired bacteria are present in very low concentrations

False

Turbidity is an indirect measurement of bacterial growth that can be measured using a pectrophotometer

True

Filtration methods are used to count bacteria present in very low concentrations, such as in lakes and streams

True

Nitrogen-fixing bacteria, such as cyanobacteria, can use atmospheric nitrogen for their nitrogen source

True