The agar in nutrient agar microbiological growth medium serves as a

1. The agar in nutrient agar microbiological growth medium serves as a——. A. carbohydrate source B. solidifying agent C. medium supplement D. protein source
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2. The agar in nutrient agar microbiological growth medium serves as a——.

A. carbohydrate source

B. solidifying agent

C. medium supplement

D. protein source

2. A mycelium is _.

A. mutualistic relationship between a fungus and a plant

B. a reproductive structure in fungi

C. a mass of connected fungal hypae

D. a partition that divided fungal hyphae into cell like compartments

3. Cleaning the wound with Hydrogen peroxide is an example of

A. bacteriostasis

B. sterilization

C. antisepis

D. disinfection

4. You are asked to prepare 5% bleach solution to be used on certain surfaces at work. The only Bleach solution you have available is 10%. In order to make the desired dilution what is the volume of 10% bleach you will use to make 1000 ml of bleach solution.

A. Take 150 ml of 10% bleach and make the volume up to 1000 ml

B. Take 50 ml of 10% bleach and make the volume up to 1000 ml

C. Take 5 ml of 10% bleach and make the volume up to 1000 ml

D. Take 500 ml of 10% bleach and make the volume up to 1000 ml

5. Protozoa are exclusively unicellular prokaryotes.

True

False

6. Which of the following statement describes fungi

A. all are eukaryotic, muticellular autotrophs

B. all are eukaryotic heterotrophs that feed by ingestion

C. all are prokaryotic multicellular autotrophs

D. all are eukaryotic heterotrophs that feed by absorption

7. It is extremely important for swabbed patient’s samples to be collected in transportation media why?

A. you can still isolate the pathogen from any body fluid sample no matter how you collect it

B. so that it can represent the exact microbial flora as present in the patient’s body

C. so that it can be used to obtain a mixed culture

D. it will not matter at all for urine samples

8. The shortest wavelength of uv rays is most damaging to microbial cells.

True

False

9. Human bacterial pathogens grow in the laboratory grow best at——-.

A. 45 degrees celsius

B. 25 degrees celsius

C. 35 degrees celsius

D. 20 degrees celsius

10. A bacteria growing on the surface of broth in the form of pellicle, it is categorized as a/an

A. aerotolerant anaerobes

B. obligate aerobes

C. facultative anaerobes

D. obligate anaerobes

The Correct Answer and Explanation is :

Here are the correct answers and explanations for each question:

1. The agar in nutrient agar microbiological growth medium serves as a——. Answer: B. solidifying agent Explanation: Agar is a gelatinous substance derived from seaweed and is used in microbiological media primarily to solidify the medium. It does not provide nutrients to the microorganisms, which is the role of the nutrients in the medium itself. Agar’s function is to provide a solid surface on which microorganisms can grow.
2. A mycelium is _. Answer: C. a mass of connected fungal hyphae Explanation: Mycelium is a network of hyphae (the thread-like structures of a fungus) that form the vegetative part of the fungus. This structure grows and spreads out to help absorb nutrients and allows the fungus to expand.
3. Cleaning the wound with Hydrogen peroxide is an example of Answer: C. antisepsis Explanation: Antisepsis refers to the use of chemicals to reduce or eliminate harmful microorganisms on living tissues, like cleaning a wound with hydrogen peroxide to prevent infection. Sterilization, on the other hand, is the complete elimination of all microorganisms, while bacteriostasis and disinfection involve controlling or reducing bacterial growth but in different contexts.
4. You are asked to prepare a 5% bleach solution to be used on certain surfaces at work. The only Bleach solution you have available is 10%. In order to make the desired dilution, what is the volume of 10% bleach you will use to make 1000 ml of bleach solution? Answer: B. Take 50 ml of 10% bleach and make the volume up to 1000 ml Explanation: To make a 5% bleach solution from a 10% bleach solution, use the dilution formula:
   ( C_1 \times V_1 = C_2 \times V_2 )
   where ( C_1 ) is the initial concentration, ( V_1 ) is the volume of the concentrated solution needed, ( C_2 ) is the final concentration, and ( V_2 ) is the final volume. Substituting values, ( 10\% \times V_1 = 5\% \times 1000 \, \text{ml} ). Solving gives ( V_1 = 50 \, \text{ml} ).
5. Protozoa are exclusively unicellular prokaryotes. Answer: False Explanation: Protozoa are unicellular eukaryotic organisms, not prokaryotic. Prokaryotes lack a defined nucleus, whereas protozoa are eukaryotic, meaning they have membrane-bound organelles and a defined nucleus.
6. Which of the following statements describes fungi? Answer: D. all are eukaryotic heterotrophs that feed by absorption Explanation: Fungi are eukaryotic organisms, meaning they have complex cells with a nucleus and other organelles. They are heterotrophs, which means they cannot produce their own food but absorb nutrients from other organic material, such as dead organisms or decomposing material.
7. It is extremely important for swabbed patient’s samples to be collected in transportation media. Why? Answer: B. so that it can represent the exact microbial flora as present in the patient’s body Explanation: Transportation media help preserve the integrity of the sample and maintain the viability of microorganisms while preventing overgrowth of any one species. This ensures that the sample accurately represents the microbial flora from the patient’s body.
8. The shortest wavelength of UV rays is most damaging to microbial cells. Answer: True Explanation: Shorter wavelengths of ultraviolet (UV) light, particularly UV-C (100-280 nm), are the most damaging to microbial cells because they are absorbed by DNA, causing mutations that can lead to the death of the microorganism.
9. Human bacterial pathogens grow in the laboratory grow best at——-. Answer: C. 35 degrees celsius Explanation: Most human pathogens grow best at body temperature, which is around 37°C. However, many grow effectively at slightly lower temperatures (like 35°C) in the laboratory to simulate the conditions inside the human body.
10. A bacteria growing on the surface of broth in the form of pellicle, it is categorized as a/an Answer: B. obligate aerobes Explanation: Obligate aerobes require oxygen for growth and can form a pellicle (a thin film) on the surface of liquid media due to their need to access oxygen in the air. This is characteristic of aerobic bacteria that grow at the air-medium interface.

These answers and explanations provide clarity on microbiological concepts and laboratory practices.