CCRI MICRO FINAL PAPER 2025/2026 QUESTIONS AND
ANSWERS RATED A+
✔✔QUATS - ✔✔disinfectant
✔✔Chemical food preservers - ✔✔organic acids
-used against mold
-Sorbic acid, benzoic acid, calcium propionate
✔✔Nitrates and nitrites - ✔✔used to inhibit growth of microbes
-used in meats
✔✔Aldehydes - ✔✔preserve animals
✔✔Gaseous chemosteralizers - ✔✔steralizes gas
✔✔Penicillin - ✔✔Alexander Fleming
-goes after the cell wall
✔✔overuse of antibiotics - ✔✔causes organisms to become resistant to the antibiotics
✔✔Antimicrobial drugs - ✔✔hit cell wall, cell membrane, DNA replication, RNA
transcription, biochemical reactions, protein synthesis
-go after certain part of organism (^)
✔✔Chloramphenicol - ✔✔binds to the 50s portion of ribosome & inhibits formation of
peptide bond
✔✔Tetracyclines - ✔✔interfere with attachment of tRNA to mRNA-ribosoms complex
(stops protein synthesis)
✔✔Streptomycin - ✔✔changes shape of 30s
interferes with protein synthesis
✔✔Erythromycin - ✔✔binds to 50s and prevents movement of ribosome along mRNA
✔✔Gentimycin - ✔✔binds to 30s
interrupting protein syntheses
✔✔membrane has its own way of disturbing the bacterial membrane - ✔✔can kill it
✔✔Polymyxin B - ✔✔kills bacteria
(injures plasma membrane)
, ✔✔Ketoconazole - ✔✔used on fungal diseases
✔✔Inhibition of nucleic acid synthesis - ✔✔Stop DNA from replicating
✔✔Pecking order (most to least resistant) - ✔✔1. Prions
2. endospores of bacteria
3. mycobacteria
4.cysts of protozoa
5.vegetative protozoa
6. gram-neg. bacteria
7. fungi, including most fungal spore forms
8. viruses without envelopes
9. gram positive bacteria
10. viruses with lipid envelope
✔✔Glycolosis - ✔✔takes place in the cytoplasm
✔✔Krebs - ✔✔Eukaryotic: takes place in the matrix
Bacteria: takes place in the cytoplasm
✔✔Electrontansport - ✔✔takes place in the inner membrane (cristae)
✔✔ Chlorine and iodine are classified as - ✔✔halogens
✔✔Obligate aerobes can only live - ✔✔when oxygen is present
✔✔Microorganism found thriving in a the permafrost region of the Arctic are -
✔✔pychrophiles
✔✔Facultative halophiles - ✔✔tolerate an elevated salt concentration in the
environment
✔✔Most bacteria prefer to grow at which pH range? - ✔✔Most bacteria prefer to grow at
which pH range?
✔✔The spectrophotometer is used in microbiology to - ✔✔indirectly measure microbial
growth
✔✔Pyrimidine dimers are formed in DNA when DNA - ✔✔absorbs UV radiation
✔✔These microorganisms are anaerobic but can live in the presence of oxygen even
though they do not actually use the oxygen - ✔✔aerotolerant
ANSWERS RATED A+
✔✔QUATS - ✔✔disinfectant
✔✔Chemical food preservers - ✔✔organic acids
-used against mold
-Sorbic acid, benzoic acid, calcium propionate
✔✔Nitrates and nitrites - ✔✔used to inhibit growth of microbes
-used in meats
✔✔Aldehydes - ✔✔preserve animals
✔✔Gaseous chemosteralizers - ✔✔steralizes gas
✔✔Penicillin - ✔✔Alexander Fleming
-goes after the cell wall
✔✔overuse of antibiotics - ✔✔causes organisms to become resistant to the antibiotics
✔✔Antimicrobial drugs - ✔✔hit cell wall, cell membrane, DNA replication, RNA
transcription, biochemical reactions, protein synthesis
-go after certain part of organism (^)
✔✔Chloramphenicol - ✔✔binds to the 50s portion of ribosome & inhibits formation of
peptide bond
✔✔Tetracyclines - ✔✔interfere with attachment of tRNA to mRNA-ribosoms complex
(stops protein synthesis)
✔✔Streptomycin - ✔✔changes shape of 30s
interferes with protein synthesis
✔✔Erythromycin - ✔✔binds to 50s and prevents movement of ribosome along mRNA
✔✔Gentimycin - ✔✔binds to 30s
interrupting protein syntheses
✔✔membrane has its own way of disturbing the bacterial membrane - ✔✔can kill it
✔✔Polymyxin B - ✔✔kills bacteria
(injures plasma membrane)
, ✔✔Ketoconazole - ✔✔used on fungal diseases
✔✔Inhibition of nucleic acid synthesis - ✔✔Stop DNA from replicating
✔✔Pecking order (most to least resistant) - ✔✔1. Prions
2. endospores of bacteria
3. mycobacteria
4.cysts of protozoa
5.vegetative protozoa
6. gram-neg. bacteria
7. fungi, including most fungal spore forms
8. viruses without envelopes
9. gram positive bacteria
10. viruses with lipid envelope
✔✔Glycolosis - ✔✔takes place in the cytoplasm
✔✔Krebs - ✔✔Eukaryotic: takes place in the matrix
Bacteria: takes place in the cytoplasm
✔✔Electrontansport - ✔✔takes place in the inner membrane (cristae)
✔✔ Chlorine and iodine are classified as - ✔✔halogens
✔✔Obligate aerobes can only live - ✔✔when oxygen is present
✔✔Microorganism found thriving in a the permafrost region of the Arctic are -
✔✔pychrophiles
✔✔Facultative halophiles - ✔✔tolerate an elevated salt concentration in the
environment
✔✔Most bacteria prefer to grow at which pH range? - ✔✔Most bacteria prefer to grow at
which pH range?
✔✔The spectrophotometer is used in microbiology to - ✔✔indirectly measure microbial
growth
✔✔Pyrimidine dimers are formed in DNA when DNA - ✔✔absorbs UV radiation
✔✔These microorganisms are anaerobic but can live in the presence of oxygen even
though they do not actually use the oxygen - ✔✔aerotolerant
