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BIOS 242 / BIOS242 – Fundamentals of Microbiology
Lab Practicum (Chamberlain University, 2026) Verified
Questions and Answers, Grade A
Subject: Fundamentals of Microbiology Lab
Source: BIOS 242 Lab Practicum, Chamberlain University (2026)
Format: Key Concepts & Definitions
1. Special Stain:
Targets specific microbial structures (e.g., endospores, flagella).
Examples: Endospore stain, Capsule stain.
2. Pasteurization Purpose:
Reduces microbial load to prevent food spoilage and enhance safety.
3. Pasteurization Processes:
LTLT (Low Temperature, Long Time): 63°C for 30 minutes.
HTST (High Temperature, Short Time): 72°C for 15 seconds.
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UHT (Ultra-High Temperature): 135°C for 2–5 seconds.
4. Food Spoilage:
Caused by microbial toxins, enzymes, and fermentation.
5. Purpose of Streak Plate Method:
To isolate pure bacterial colonies for study.
Process:
1. Streak a small sample onto agar using a sterilized loop.
2. Spread the inoculum into different sections to separate cells.
3. Isolated cells grow into distinct colonies.
6. HEPA Filters:
High-Efficiency Particulate Air filters remove 99.97% of particles ≥0.3
microns.
Used in BSL-3 and BSL-4 labs.
Filters microbes and particulates using synthetic fibers or fiberglass.
7. Bacterial Multiplication and Doubling Time:
Bacteria reproduce by binary fission.
Doubling Time: Time required for a bacterial population to double.
BIOS 242 / BIOS242 – Fundamentals of Microbiology
Lab Practicum (Chamberlain University, 2026) Verified
Questions and Answers, Grade A
Subject: Fundamentals of Microbiology Lab
Source: BIOS 242 Lab Practicum, Chamberlain University (2026)
Format: Key Concepts & Definitions
1. Special Stain:
Targets specific microbial structures (e.g., endospores, flagella).
Examples: Endospore stain, Capsule stain.
2. Pasteurization Purpose:
Reduces microbial load to prevent food spoilage and enhance safety.
3. Pasteurization Processes:
LTLT (Low Temperature, Long Time): 63°C for 30 minutes.
HTST (High Temperature, Short Time): 72°C for 15 seconds.
, 2|Page
UHT (Ultra-High Temperature): 135°C for 2–5 seconds.
4. Food Spoilage:
Caused by microbial toxins, enzymes, and fermentation.
5. Purpose of Streak Plate Method:
To isolate pure bacterial colonies for study.
Process:
1. Streak a small sample onto agar using a sterilized loop.
2. Spread the inoculum into different sections to separate cells.
3. Isolated cells grow into distinct colonies.
6. HEPA Filters:
High-Efficiency Particulate Air filters remove 99.97% of particles ≥0.3
microns.
Used in BSL-3 and BSL-4 labs.
Filters microbes and particulates using synthetic fibers or fiberglass.
7. Bacterial Multiplication and Doubling Time:
Bacteria reproduce by binary fission.
Doubling Time: Time required for a bacterial population to double.
