Question 1

All the following colors are commonly used to describe bacteria, except

Accepted Answer

Buff, white, and gray are common colors used to describe bacterial colonies, while orange is not typically used to describe bacteria.

Question 2

What organism forms a small, fuzzy-edged colony with an umbonate center on blood or CHOC agar?

Accepted Answer

Eikenella corrodens is known for forming small colonies with a characteristic fuzzy edge and a slightly raised center (umbonate) when cultured on blood or chocolate agar.

Question 3

When looking at a tube of thioglycollate broth, streamers or vines and puffballs are visible. What organism grows like this in thioglycollate?

Accepted Answer

Streptococcus spp. are known to form streamers or vines and puffballs in thioglycollate broth due to their growth pattern in this medium.

Question 4

The density of the bacterial colony can be described by all the following, except

Accepted Answer

The answer of The density of the bacterial colony can...

Question 5

The elevation of bacterial colonies is described by all the following, except

Accepted Answer

The elevation of bacterial colonies can be described as raised, convex, or umbilicate, but "pointed" is not a term typically used to describe the elevation of bacterial colonies. Instead, terms like "pointed" might be used to describe the shape of individual bacteria or the margin of a colony, but not its elevation.

Question 6

A microbiologist is reading a vaginal culture. She sees the very white colonies that are non -hemolytic on a BAP but appear to have feet. What organism could this possibly be?

Accepted Answer

The description of very white colonies that appear to have "feet" is characteristic of yeast, particularly Candida species, which can form pseudohyphae or "feet" extending from the colonies. This is a common finding in vaginal cultures when yeast infection is present.

Question 7

The term used to describe colonies that are solid in color and that do not allow any light to pass through is

Accepted Answer

The term opaque is used to describe materials or substances that do not allow light or any other form of radiation to pass through them. Therefore, colonies that are solid in color and do not allow any light to pass through them would be described as opaque.

Question 8

All of the following terms are used to describe the consistency of a bacterial colony, except

Accepted Answer

The answer of All of the following terms are used...

Question 9

A term used to describe colonies that resemble coins is

Accepted Answer

The term "umbilicate" is used to describe colonies that resemble coins with central depressions or indents, just like the umbilicus on a belly button. The term "umbonate" is used to describe colonies with central elevations or bumps. "Flat" and "raised" are too general to specifically describe colonies that resemble coins.

Question 10

All of the following characteristics are used to describe bacterial colony characteristics, except

Accepted Answer

Temperature is not a characteristic used to describe bacterial colony growth or appearance. The other characteristics listed (hemolysis, color, and elevation) are commonly used to identify and classify bacterial colonies.

Quiz 8: Use of Colony Morphology for the Presumptive Identification of Microorganisms