$$1 \text{ km} = 10^6$ \text{ mm}$$

Question 1

Which of the following best describes a pathogen?

Accepted Answer

A microorganism that causes disease.

Question 2

According to binomial nomenclature, which part of the name Escherichia coli refers to the genus?

Accepted Answer

Escherichia

Question 3

Which of the following statements about fermentation is correct?

Accepted Answer

It occurs without oxygen and produces lactic acid or alcohol.

Question 4

Pasteur’s experiments disproved which theory?

Accepted Answer

Spontaneous generation

Question 5

Which of the following is NOT a benefit provided by normal microbiota?

Accepted Answer

Causing infectious diseases

Question 6

What is the total magnification when using a 10x eyepiece and a 40x objective lens?

Accepted Answer

$$10 	imes 40 = 400x$$

Question 7

Which step in Gram staining is responsible for differentiating between Gram-positive and Gram-negative bacteria?

Accepted Answer

Alcohol decolorizer

Question 8

A bacterium is observed to be pink after Gram staining. What can you infer about its cell wall?

Accepted Answer

It has a thin peptidoglycan layer and an outer membrane.

Question 9

Which of the following antibiotics targets bacterial cell walls and is an example of selective toxicity?

Accepted Answer

Penicillin

Question 10

Which of the following statements about prokaryotic DNA is correct?

Accepted Answer

It is usually a single, circular chromosome located in the nucleoid.

Question 11

Which of the following best explains why lysozyme is more effective against Gram-positive bacteria?

Accepted Answer

Gram-positive bacteria have a thick, exposed peptidoglycan layer.

Question 12

Which of the following is NOT a function of endospores?

Accepted Answer

Reproduction

Question 13

Which of the following organisms does NOT have a cell wall?

Accepted Answer

Animal cells

Question 14

A solution is hypertonic to a bacterial cell. What will happen to the cell?

Accepted Answer

It will lose water and shrink.

Question 15

Which process moves substances against their concentration gradient and requires energy?

Accepted Answer

Active transport

Question 16

Which of the following best describes the function of chromatophores in some bacteria?

Accepted Answer

Sites of photosynthesis

Question 17

Which of the following is a correct metric conversion?

Accepted Answer

$$1 	ext{ km} = 10^6$ 	ext{ mm}$$

Question 18

Which of the following is a real-world example of bioremediation by microorganisms?

Accepted Answer

Using bacteria to clean up oil spills

Question 19

Which of the following best explains why oil immersion is used with the 100x objective in microscopy?

Accepted Answer

It matches the refractive index of glass, reducing light loss.

Question 20

Which of the following is a correct sequence for the path of light through a compound microscope?

Accepted Answer

Light source $$\rightarrow$$ condenser $$\rightarrow$$ specimen $$\rightarrow$$ objective lens $$\rightarrow$$ eyepiece $$\rightarrow$$ eye

Microbiology Study Notes: Introduction, Microscopy, and Prokaryotic Cells

Study Guide - Practice Questions