BIOL 2051 LAB MIDTERM EXAM Questions with 100%
Verified Answers Latest Update
Question: Name six categories of colony morphology properties which can be used to
describe the growth of a microorganism
Answer:
1. whole colony shape
2. margin shape
3. elevation
4. optical properties
5. surface characteristics
6. pigementation
Question: What can influence the colony morpholoy properties of a microorganism?
Answer:
media used
Question:
Answer:
Question:
Answer:
Question:
Answer:
Question: Describe the growth medium used for experiment one. Would a broth culture
work just as well?
Answer:
TSA (trypticase soy agar) is a solid medium in a petri dish
Using a broth culture would make it difficult to determine colony morphology because the
microorganisms are suspended in the liquid. We would be unable to see colony morphology.
Question: Some areas sampled had more microorganisms capable of growing on TSA than
other areas. Give a couple of explanations as to why this was observed.
Answer:
The type and amount of nutrients present in the medium will influence the size, shape, and
even color of the colony. The nutrients available in the medium may not have been suitable
for growth. Most of the areas sampled that had a high average number of colony
,morphologies were high traffic areas that would regularly come into contact with these
microbes. The area with the lowest averages are areas that may be cleaned more regularly
or do not come into contact with as many microbes as high traffic areas.
Question: Do microorganisms live in all the areas sampled or might some just be transiently
there? List the areas sampled where microorganisms are most likely to be residents.
Consider the areas where transient microbes were found. How did the microbes get to these
areas?
Answer:
Areas with resident microbes could be mouth/nose, fingers, and hair. These areas can also
contain transient microbes transferred onto these areas through daily activities. Areas with
transient microbes can also be floor, sink, clothes, air, and dirt.
Question: Where did the microbes come from that landed on the agar surface of the plate
left open for 30 minutes?
Answer:
Airborne particles containing microbes could have landed onto the afar plate and stuck to
agar. For ex-ample, sneezing, coughing, breathing, etc. could be common methods of
transport for these airborne mi-crobes.
Question: Which of the sites tested are sources of contamination when working with
cultures at your lab bench? Suggest a way to prevent contamination from each of these
sites.
Answer:
Airborne particles containing microbes could have landed onto the afar plate and stuck to
agar. For ex-ample, sneezing, coughing, breathing, etc. could be common methods of
transport for these airborne mi-crobes.
Question: Three descriptions of whole colony shape
Answer:
1. round
2. irregular
3. rhizoid
Question: Three descriptions of margin shape of colony
Answer:
1. smooth, entire
2. lobate
3. filamentous
Question: Three descriptions of elevation of colony
, Answer:
1. convex
2. umbonate (button-like)
3. flat
Question: Three descriptions of optical properties of colony
Answer:
1. opaque
2. semi-translucent
3. translucent
Question: _______ means you can not see through it
Answer:
opaque
Question: ____ means you can see through edges of the colony but not the center
Answer:
semi-translucent
Question: ________ means you can see through it
Answer:
translucent
Question: Pigmentation means ______
Answer:
color
Question: Which soap tested was the most effective in reducing the number of bacteria
present? the least effective?
Answer:
most effective: softsoap antibacterial liquid soap least effective: softsoap NON antibacterial
liquid soap
Question: Since most of the normal flora is not harmful, why must it be removed in a
surgical scrub?
Answer:
they could be harmful if introduced into the bloodstream or tissue; to prevent nosocomial or
hospital-acquired infections
Verified Answers Latest Update
Question: Name six categories of colony morphology properties which can be used to
describe the growth of a microorganism
Answer:
1. whole colony shape
2. margin shape
3. elevation
4. optical properties
5. surface characteristics
6. pigementation
Question: What can influence the colony morpholoy properties of a microorganism?
Answer:
media used
Question:
Answer:
Question:
Answer:
Question:
Answer:
Question: Describe the growth medium used for experiment one. Would a broth culture
work just as well?
Answer:
TSA (trypticase soy agar) is a solid medium in a petri dish
Using a broth culture would make it difficult to determine colony morphology because the
microorganisms are suspended in the liquid. We would be unable to see colony morphology.
Question: Some areas sampled had more microorganisms capable of growing on TSA than
other areas. Give a couple of explanations as to why this was observed.
Answer:
The type and amount of nutrients present in the medium will influence the size, shape, and
even color of the colony. The nutrients available in the medium may not have been suitable
for growth. Most of the areas sampled that had a high average number of colony
,morphologies were high traffic areas that would regularly come into contact with these
microbes. The area with the lowest averages are areas that may be cleaned more regularly
or do not come into contact with as many microbes as high traffic areas.
Question: Do microorganisms live in all the areas sampled or might some just be transiently
there? List the areas sampled where microorganisms are most likely to be residents.
Consider the areas where transient microbes were found. How did the microbes get to these
areas?
Answer:
Areas with resident microbes could be mouth/nose, fingers, and hair. These areas can also
contain transient microbes transferred onto these areas through daily activities. Areas with
transient microbes can also be floor, sink, clothes, air, and dirt.
Question: Where did the microbes come from that landed on the agar surface of the plate
left open for 30 minutes?
Answer:
Airborne particles containing microbes could have landed onto the afar plate and stuck to
agar. For ex-ample, sneezing, coughing, breathing, etc. could be common methods of
transport for these airborne mi-crobes.
Question: Which of the sites tested are sources of contamination when working with
cultures at your lab bench? Suggest a way to prevent contamination from each of these
sites.
Answer:
Airborne particles containing microbes could have landed onto the afar plate and stuck to
agar. For ex-ample, sneezing, coughing, breathing, etc. could be common methods of
transport for these airborne mi-crobes.
Question: Three descriptions of whole colony shape
Answer:
1. round
2. irregular
3. rhizoid
Question: Three descriptions of margin shape of colony
Answer:
1. smooth, entire
2. lobate
3. filamentous
Question: Three descriptions of elevation of colony
, Answer:
1. convex
2. umbonate (button-like)
3. flat
Question: Three descriptions of optical properties of colony
Answer:
1. opaque
2. semi-translucent
3. translucent
Question: _______ means you can not see through it
Answer:
opaque
Question: ____ means you can see through edges of the colony but not the center
Answer:
semi-translucent
Question: ________ means you can see through it
Answer:
translucent
Question: Pigmentation means ______
Answer:
color
Question: Which soap tested was the most effective in reducing the number of bacteria
present? the least effective?
Answer:
most effective: softsoap antibacterial liquid soap least effective: softsoap NON antibacterial
liquid soap
Question: Since most of the normal flora is not harmful, why must it be removed in a
surgical scrub?
Answer:
they could be harmful if introduced into the bloodstream or tissue; to prevent nosocomial or
hospital-acquired infections
