Question 1

A microbiologist inoculates Staphylococcus aureus into a culture medium.Following incubation,both Staphylococcus aureus and Staphylococcus epidermidis are determined to be growing in this culture.What is the most likely explanation?

Accepted Answer

The presence of both Staphylococcus aureus and Staphylococcus epidermidis in the culture suggests that it was contaminated with multiple bacterial species.

Question 2

The bacterium Neisseria gonorrhoeae causes the sexually-transmitted infection gonorrhea.Although it can be isolated from the vagina,there are numerous normal biota in that location as well.To generate a pure culture of this pathogenic bacterium,the best choice is a(n)______.

Accepted Answer

Selective medium would be the best choice for isolating N. gonorrhoeae from other normal biota in the vagina. Selective medium contains ingredients that inhibit the growth of non-target organisms, allowing the target organism to grow and form a pure culture.

Question 3

Newly inoculated cultures must be _____ at a specific temperature and time to encourage growth.

Accepted Answer

Inoculated cultures need to be incubated at specific temperature and time to encourage growth.

Question 4

Humans can see objects as small as 0.1 mm.Leeuwenhoek's best microscope could magnify objects to 300X.Which of the following would be invisible using Leeuwenhoek's microscope?

Accepted Answer

Leeuwenhoek's microscope could only magnify up to 0.1 mm, while the poliovirus is only 30 nm in size, which is too small to be seen with his microscope.

Question 5

Thioglycolate medium contains the following: yeast extract,pancreatic digest of casein,glucose,L-cysteine,sodium chloride,sodium thioglycolate,and agar.It is considered a complex medium because

Accepted Answer

The answer of Thioglycolate medium contains the following: yeast extract,pancreatic...

Question 6

Which isolation technique is most effective for the majority of applications and is most commonly used for colony isolation in the laboratory?

Accepted Answer

Streak plate technique is the most effective and commonly used for colony isolation in the laboratory. It involves streaking the sample onto the surface of an agar plate in a pattern that results in isolated colonies. Other techniques like pour plate and spread plate involve mixing the sample with agar before plating, which may lead to overgrowth and hindrance in colony isolation. Loop dilution is used for quantitative analysis of bacterial populations and not for colony isolation. Culture plate is not a specific isolation technique.

Question 7

Table 3.6 in your textbook uses Paramecium to illustrate several types of light microscopy.Each image is magnified 230X and measures about 4 cm.The actual size of a Paramecium is about ______.

Accepted Answer

To find the actual size of Paramecium, we can use the formula:
magnification = size of image / actual size
230X = 4 cm / actual size
actual size = 4 cm / 230X = 0.017 cm or 175 μm. Therefore, the best choice is C, which is 175 μm.

Question 8

Robert Koch and his colleagues first used agar in bacteriological media.Why was this ingredient an improvement on previous materials used to culture bacteria?

Accepted Answer

Agar is a solidifying agent that does not break down or degrade during the culturing process, allowing for stable and consistent growth of bacteria. This was an improvement over previous materials that were either too soft or would break down, making it difficult to maintain pure cultures.

Question 9

A microbiologist inoculates Staphylococcus epidermidis and Escherichia coli into a culture medium.Following incubation,only the E.coli grows in the culture.What is the most likely explanation?

Accepted Answer

The culture medium is likely selective and only allows the growth of one type of microorganism (in this case, E.coli).

Question 10

The procedures for culturing a microorganism require the use of a microscope.

Accepted Answer

The procedures for culturing a microorganism involve the creation of an appropriate growth medium and the use of sterile techniques to transfer the microorganism to the medium. Culturing does not necessarily require the use of a microscope, although one may be used at various stages to observe the growth and characteristics of the microorganism.

Question 11

Your microscope has a resolving power of 0.15 $\mu$m.The specimen that you will be observing has bacterial cocci the size of 0.1 $\mu$m in diameter.Which of the following statements is correct?

Accepted Answer

The answer of Your microscope has a resolving power of...

Question 12

The Five I's of studying microorganisms include all of the following except ______.

Accepted Answer

The five I's of studying microorganisms are inoculation, incubation, isolation, inspection and identification. Infection is not one of the I's.

Question 13

A microbiology student with a visual disability is viewing a sample of Bacillus endospores in a phase contrast microscope that is linked to an iPad.By "stretching" the image on the iPad screen,the student can increase the apparent size of the endospores.How does this manipulation affect resolution and contrast? (No software is being used to alter the image!)

Accepted Answer

Stretching the image on the iPad screen only increases the apparent size of the endospores, which is equivalent to increasing the magnification. However, it does not alter the resolution or contrast of the image, as these are fixed properties of the microscope and the sample being observed. Therefore, choice A is the correct answer.

Question 14

Cells of Staphylococcus aureus are cocci measuring about 1 $\mu$m in diameter.In a textbook image of S. aureus,each cell measures about 1 cm.The magnification of the image on the page is ______.

Accepted Answer

1 cm = 10,000 $\mu$m. So the magnification is 10,000X.

Question 15

The term that refers to the purposeful addition of microorganisms into a laboratory nutrient medium is ______.

Accepted Answer

Inoculation refers to the intentional introduction of microorganisms into a laboratory nutrient medium for the purpose of cultivation and study. Contamination refers to the unintended introduction of unwanted microorganisms into a culture, while infection refers to invasion and growth of harmful microorganisms in a host organism. Immunization refers to the process of making an individual immune to a specific disease by administering a vaccine or other preparations. Isolation refers to the separation of microorganisms from a mixed culture by streaking or other methods.

Question 16

A pure culture contains

Accepted Answer

A pure culture contains only one identified species of microorganism. The other choices are not specific enough and do not accurately describe what a pure culture is.

Question 17

Agar is an important component of media because

Accepted Answer

Agar provides a solid surface for bacterial growth.

Question 18

The correct microbiological term for the sample of specimen that is put into a nutrient medium to produce a culture is ______.

Accepted Answer

The correct microbiological term for the sample of specimen that is put into a nutrient medium to produce a culture is the inoculum. The loop (A) is a tool used to transfer bacteria from one source to another. Streaking (C) is a technique used to isolate bacteria on a plate. A colony (D) is a visible mass of microorganisms that originated from a single mother cell.

Question 19

Which of the following is not an inoculating tool?

Accepted Answer

A Petri dish is not an inoculating tool, but rather a container used to hold the agar or other culture medium. The other options listed are all commonly used inoculating tools in microbiology.

Question 20

What is the term for a culture made from one isolated colony?

Accepted Answer

Axenic and pure cultures both refer to cultures derived from a single type of organism, without contamination from other types. Axenic specifically means free from other living organisms, while pure indicates it originates from a single clone or cell type.

Quiz 3: Tools of the Laboratory: Methods for the Culturing of Microscopic Analysis of Microorganisms

A microbiologist inoculates Staphylococcus aureus into a culture medium.Following incubation,both Staphylococcus aureus and Staphylococcus epidermidis are determined to be growing in this culture.What is the most likely explanation?

The bacterium Neisseria gonorrhoeae causes the sexually-transmitted infection gonorrhea.Although it can be isolated from the vagina,there are numerous normal biota in that location as well.To generate a pure culture of this pathogenic bacterium,the best choice is a(n) ______.

Newly inoculated cultures must be _____ at a specific temperature and time to encourage growth.

Humans can see objects as small as 0.1 mm.Leeuwenhoek's best microscope could magnify objects to 300X.Which of the following would be invisible using Leeuwenhoek's microscope?

Thioglycolate medium contains the following: yeast extract,pancreatic digest of casein,glucose,L-cysteine,sodium chloride,sodium thioglycolate,and agar.It is considered a complex medium because

Which isolation technique is most effective for the majority of applications and is most commonly used for colony isolation in the laboratory?

Table 3.6 in your textbook uses Paramecium to illustrate several types of light microscopy.Each image is magnified 230X and measures about 4 cm.The actual size of a Paramecium is about ______.

Robert Koch and his colleagues first used agar in bacteriological media.Why was this ingredient an improvement on previous materials used to culture bacteria?

A microbiologist inoculates Staphylococcus epidermidis and Escherichia coli into a culture medium.Following incubation,only the E.coli grows in the culture.What is the most likely explanation?

The procedures for culturing a microorganism require the use of a microscope.

Your microscope has a resolving power of 0.15 $\mu$ m.The specimen that you will be observing has bacterial cocci the size of 0.1 $\mu$ m in diameter.Which of the following statements is correct?

The Five I's of studying microorganisms include all of the following except ______.

Cells of Staphylococcus aureus are cocci measuring about 1 $\mu$ m in diameter.In a textbook image of S. aureus,each cell measures about 1 cm.The magnification of the image on the page is ______.

The term that refers to the purposeful addition of microorganisms into a laboratory nutrient medium is ______.

A pure culture contains

Agar is an important component of media because

The correct microbiological term for the sample of specimen that is put into a nutrient medium to produce a culture is ______.

Which of the following is not an inoculating tool?

What is the term for a culture made from one isolated colony?

Quiz 3: Tools of the Laboratory: Methods for the Culturing of Microscopic Analysis of Microorganisms

A microbiologist inoculates Staphylococcus aureus into a culture medium.Following incubation,both Staphylococcus aureus and Staphylococcus epidermidis are determined to be growing in this culture.What is the most likely explanation?

The bacterium Neisseria gonorrhoeae causes the sexually-transmitted infection gonorrhea.Although it can be isolated from the vagina,there are numerous normal biota in that location as well.To generate a pure culture of this pathogenic bacterium,the best choice is a(n) ______.

Newly inoculated cultures must be _____ at a specific temperature and time to encourage growth.

Humans can see objects as small as 0.1 mm.Leeuwenhoek's best microscope could magnify objects to 300X.Which of the following would be invisible using Leeuwenhoek's microscope?

Thioglycolate medium contains the following: yeast extract,pancreatic digest of casein,glucose,L-cysteine,sodium chloride,sodium thioglycolate,and agar.It is considered a complex medium because

Which isolation technique is most effective for the majority of applications and is most commonly used for colony isolation in the laboratory?

Table 3.6 in your textbook uses Paramecium to illustrate several types of light microscopy.Each image is magnified 230X and measures about 4 cm.The actual size of a Paramecium is about ______.

Robert Koch and his colleagues first used agar in bacteriological media.Why was this ingredient an improvement on previous materials used to culture bacteria?

A microbiologist inoculates Staphylococcus epidermidis and Escherichia coli into a culture medium.Following incubation,only the E.coli grows in the culture.What is the most likely explanation?

The procedures for culturing a microorganism require the use of a microscope.

Your microscope has a resolving power of 0.15 μ\muμ m.The specimen that you will be observing has bacterial cocci the size of 0.1 μ\muμ m in diameter.Which of the following statements is correct?

The Five I's of studying microorganisms include all of the following except ______.

Cells of Staphylococcus aureus are cocci measuring about 1 μ\muμ m in diameter.In a textbook image of S. aureus,each cell measures about 1 cm.The magnification of the image on the page is ______.

The term that refers to the purposeful addition of microorganisms into a laboratory nutrient medium is ______.

A pure culture contains

Agar is an important component of media because

The correct microbiological term for the sample of specimen that is put into a nutrient medium to produce a culture is ______.

Which of the following is not an inoculating tool?

What is the term for a culture made from one isolated colony?

Your microscope has a resolving power of 0.15 $\mu$ m.The specimen that you will be observing has bacterial cocci the size of 0.1 $\mu$ m in diameter.Which of the following statements is correct?

Cells of Staphylococcus aureus are cocci measuring about 1 $\mu$ m in diameter.In a textbook image of S. aureus,each cell measures about 1 cm.The magnification of the image on the page is ______.