Microbiology Practical Lab - #2 10 -16 ACC Questions With 100% Correct Answers.

Microbiology Practical Lab - #2 10 -16
ACC
Aerobic respirers reduce ________________ to water or other compounds. Anerobic
respirers reduce other inorganic molecules such as ________________ or sulfate. -
✔️✔️- oxygen
- nitrate

The catalase test detects the organisms ability to produce catalase - an enzyme that
___________________ the cell by converting ____________________
__________________ (2 words) produced in the ETC to __________________ and
molecular ______________________ - ✔️✔️- detoxifies
- H202 (hydrogen peroxide)
- water
- O2

The oxidase test identifies the presence of ____________________ _____ (2 words)
oxidase in the ETC - ✔️✔️Cytochrome C

Individual microbial species in a mixed culture must be isolated and grown as
_____________________________ prior to being tested and identified. The most
common means of isolating a pure culture is to ___________________ a plate for
isolation. - ✔️✔️- pure cultures
- streak

Media that inhibits the growth of some organisms while encourages the growth of others
is referred to as ________________________ media; whereas
__________________________ media contains indicators to expose differences
between organisms. - ✔️✔️- selective
- differential

. Some differential media will detect _________________________, which are a
subgroup of Enterobacteriaceae that produce acid and gas from lactose fermentation.
The presence of these in the environment may indicate __________________
contamination, since most of these are normal inhabitants of the human intestinal tract.
- ✔️✔️- Coli-form bacteria
- fecal

_________________________ make the media selective in that they are designed to
exploit weaknesses in specific groups of organisms and thus prevent their growth. -
✔️✔️- Inhibitors

, __________________________ are almost always what makes a medium differential in
that they rely on the ability of certain microbes to perform specific chemical reactions in
a way that can be observed. - ✔️✔️- substrates

___________________________ make an expected reaction visible, are always
included in differential media. They may be dyes/pH indicators or chemicals that change
color upon a reaction - ✔️✔️Indicators

Mannitol salt agar (MSA) contains the carbohydrate (sugar)
______________________, 7.5% ______________, and the pH indicator
____________________________. - ✔️✔️- Mannitol
- NaCl
- phenol Red

The _____________________ acts as the substrate or sugar for fermentation and is
what makes the media ________________________, while the
_______________________________ is what makes the media
________________________ in that it allows for the growth of some organisms, while
inhibiting the growth of others - ✔️✔️- mannitol
- differental
- NaCl
- selective

MSA is selective for the growth of the genus, ________________________________,
due to their salt tolerance. - ✔️✔️Staphylococci

If the organism ferments mannitol on an MSA plate, the pH becomes acidic, and the pH
indicator (phenol red) changes in color from red to ___________________________. -
✔️✔️yellow

. If the organism does not ferment mannitol on an MSA plate, the pH remains neutral or
becomes basic, and the growth of the culture appears ______________ or
_____________. - ✔️✔️- Pink
- Red

. Eosin methylene blue agar contains the dyes ________________________ and
_________________________, which will inhibit the growth of most Gram-positive
bacteria. - ✔️✔️- eosiny
- methylene Blue

Eosin methylene blue agar will test for the fermentation of the sugar,
________________. - ✔️✔️Lactose