BIO 240 Quiz 3

Bacteria are usually autotrophs. (T/F)

True

What 2 other organisms are also autotrophs?

algae and plants

Some bacteria can also be heterotrophs. (T/F)

true

relationship where bacteria and man both benefit from each other

symbiosis

relationship where bacteria may benefit and man receives no real benefit or harm

commensalism

several species of bacteria accomplish together what neither bacterium could accomplish individually

synergism

an organism may be pathogenic to a host if the host's immune system is compromised; often part of host's normal flora

opportunism

relationship where one organism benefits and another is harmed

parasitism

bacteria that grow best at cold temperatures

psychrophiles

bacteria that grow best at moderate temperature

mesophiles

bacteria that grow best at warm temperatures

thermphiles

bacteria that grow in extremely warm/hot temperatures

extreme thermophiles

some organisms that are not thermophiles, but can survive (not necessarily grow) in high temperatures

thermoduric organism

Which organism would likely be most human pathogens?

mesophiles

Would psychrophiles likely be pathogenic to humans?

no, we are too warm

How do we protect our food from becoming a reservoir for mesophilic bacteria that may make us ill?

cooling or heating

Would boiling be an effective method of killing ALL thermophiles?

no, we must use an autoclave

___ require an environment that contains Oxygen

aerobes (obligate)

_____ do NOT require an oxygen environment for growth or reproduction

anaerobes (obligate)

Type of anaerobe that requires absolutely NO Oxygen

Strict anaerobe

___ _____ can grow either in the presence or absence of Oxygen

Facultative anaerobes

What category of the most clinically significant bacteria fall under?

facultative anaerobes

____ grow best in an Oxygen-limited environment

microaerophiles

Most bacteria have an internal pH of approximately _

7

Most bacteria grow best at a pH of _ to _

6;8

What is the exception to bacteria growth pH?

Helicobacter pylori

Bacteria can't grow well in hyperosmotic environments. (T/F)

True

Hugh sugar or salt content tends to draw water out of the organism, thereby ___

Dehydrating

"Salt lover"

Halophiles

What is the one common organism that can survive in salty environments?

Staphylococcus aureus

In mannitol salt agar, it is selective for the growth of the genus:

Staphylococcus

Yellow growth on mannitol salt agar is

Staphylococcus aureus

Any other staphylococcus other than aureus turns the mannitol salt agar ___

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