This section focuses on numerical, quantitative, and data-based problems related to infectious diseases and microbial growth patterns. It is designed for Class 11–12 students, NEET aspirants, and undergraduate learners to strengthen their ability to apply microbiology concepts using calculations and logical reasoning.
In this section, you will practice:
Numerical problems based on microbial population growth
Calculations involving incubation period and disease spread
Data interpretation questions related to infection rates and outbreak analysis
Graph-based problems on microbial growth curves
Numerical analysis of antibiotic effectiveness and resistance patterns
Table- and chart-based questions related to disease prevalence
NCERT-aligned numerical questions and exam-oriented practice sets
The content is structured to improve step-by-step analytical skills, enhance data interpretation, and help students confidently handle numerical and logic-based questions in school examinations, NEET, and undergraduate assessments.
Develop speed, accuracy, and confidence in solving numerical applications related to microorganisms and disease through systematic practice.
Q. A culture shows a growth of 1,200 colonies after incubation. If the dilution factor was 1:100, what was the original concentration of bacteria in the sample?
A.
120,000 CFU/mL
B.
12,000 CFU/mL
C.
1,200 CFU/mL
D.
120 CFU/mL
Solution
To find the original concentration, multiply the number of colonies by the dilution factor: 1,200 colonies * 100 = 120,000 CFU/mL.
Q. A laboratory test shows that a patient has a viral load of 5,000 copies/mL. If the treatment reduces the viral load by 80%, what is the new viral load?
A.
1,000 copies/mL
B.
2,000 copies/mL
C.
3,000 copies/mL
D.
4,000 copies/mL
Solution
An 80% reduction means that 20% of the original viral load remains. 20% of 5,000 copies/mL is 1,000 copies/mL.
Q. A patient is diagnosed with a bacterial infection and is prescribed antibiotics. If the bacteria have a resistance rate of 25%, what is the probability that a randomly selected bacterium is susceptible to the antibiotic?
A.
25%
B.
50%
C.
75%
D.
100%
Solution
If 25% of the bacteria are resistant, then 75% are susceptible to the antibiotic.
Q. What is the minimum inhibitory concentration (MIC) of a drug that inhibits 90% of a bacterial population at a concentration of 2 mg/L?
A.
1 mg/L
B.
2 mg/L
C.
3 mg/L
D.
4 mg/L
Solution
The MIC is defined as the lowest concentration of an antimicrobial that will inhibit the visible growth of a microorganism after overnight incubation. In this case, the MIC is 2 mg/L.
