Which of the following is the unit of measurement in bacteriology?

Appeared in: AIIMS Bhopal NO - 2018 (Shift-1st)

Explanation

Micron, also known as a micrometer (μm), is the standard unit used to measure the size of microscopic organisms like bacteria.
Most bacteria have dimensions that range from 0.2 to 10 micrometers, making the micron the most appropriate and practical scale for their measurement.
One micron is equivalent to one-millionth of a meter (10⁻⁶ m).
The other options represent different physical quantities: Joule (energy), Newton (force), and Pascal (pressure).

Option A: Joule (J) is the standard unit of energy or work in the International System of Units (SI). It is not a unit of length or size.
Option B: Newton (N) is the SI unit of force. It measures the interaction that causes a change in an object's motion.
Option D: Pascal (Pa) is the SI unit of pressure, defined as one newton per square meter. It is used to quantify pressure, stress, and tensile strength.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Units of measurement in bacteriology as background academic context rather than a clinical decision trigger.
Nurses need to understand microscopic measurements to correctly interpret laboratory reports on pathogens, which is crucial for guiding appropriate antimicrobial therapy.
Knowledge of bacterial size is essential for understanding the principles behind sterilization and disinfection methods, particularly filtration, where the filter's pore size (measured in microns) determines which microbes are effectively removed.
What if? If a filter with a pore size of 0.5 microns is used to sterilize a liquid, it would successfully remove most bacteria. However, if the contamination concern was viral (viruses are typically 0.02-0.3 microns), this filter would be ineffective, and a smaller pore size (nanometer range) would be required.

How to Approach the Question

First, identify the key terms in the question: 'unit of measurement' and 'bacteriology'.
Recognize that bacteriology is the study of bacteria, which are microscopic organisms, so the answer must be a unit of microscopic length.
Evaluate the given options to determine their corresponding physical quantities.
Joule is a unit of energy.
Newton is a unit of force.
Pascal is a unit of pressure.

Concept Tested & Keywords

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E6 Microbiology Essentials Sastry 4e Part 1 p. 31-33

E6 Microbiology OneStop Sastry p. 8-10

Practise the full AIIMS Bhopal NO - 2018 (Shift-1st)

Attempt every question from this paper in a timed mock, then review the full solution for each one.