Question 1

Which of the following microorganisms is typically handled in a Biosafety Level 4 (BSL-4) laboratory?

Accepted Answer

Ebola virus

Question 2

What is the primary purpose of using aseptic technique in the microbiology laboratory?

Accepted Answer

To prevent contamination of the specific microorganism and the environment

Question 3

If the ocular lens of a microscope is 10x and the objective lens is 40x, what is the total magnification?

Accepted Answer

$$10 	imes 40 = 400$$

Question 4

Which part of the microscope is responsible for adjusting the amount of light that reaches the specimen?

Accepted Answer

Iris diaphragm lever

Question 5

The ability of a microscope to keep an object in focus when changing objective lenses is called:

Accepted Answer

Parfocal

Question 6

Which of the following best describes the morphology of yeast and molds?

Accepted Answer

Yeasts are unicellular; molds are multicellular and filamentous

Question 7

Which of the following is a characteristic of a selective culture medium?

Accepted Answer

It inhibits the growth of certain bacteria while allowing others to grow

Question 8

A mixed culture refers to:

Accepted Answer

Growth of two or more different microorganisms in the same culture

Question 9

Which of the following best describes the effect of a hypertonic solution on a bacterial cell?

Accepted Answer

The cell shrivels due to water loss (plasmolysis)

Question 10

Which of the following organisms is a mesophile based on its optimal growth temperature?

Accepted Answer

An organism that grows best at $$37^\circ C$$

Question 11

Which of the following statements about chromogenesis is correct?

Accepted Answer

Pigment production in bacteria depends on enzyme activity, which is temperature-sensitive

Question 12

Which of the following best describes an acidophile?

Accepted Answer

An organism that grows best at pH 0–5.5

Question 13

Which of the following is a basic stain used in simple staining?

Accepted Answer

Methylene blue

Question 14

What is the main difference between a simple stain and a differential stain?

Accepted Answer

A simple stain uses one dye; a differential stain uses two or more dyes to distinguish cell types

Question 15

Which of the following best describes the function of sodium thioglycollate in culture media?

Accepted Answer

It reduces oxygen to create an anaerobic environment

Question 16

Which of the following best describes the arrangement and shape of bacteria shown in a negative stain?

Accepted Answer

The background is stained, revealing the size, shape, and arrangement of live, unstained bacteria

Question 17

Which of the following is true about the reproduction of protozoa?

Accepted Answer

Most protozoa reproduce asexually

Question 18

Which of the following best describes the nutritional mode of most algae?

Accepted Answer

Photoautotrophic

Question 19

Which of the following is a correct statement about the function of exoenzymes in fungi?

Accepted Answer

Exoenzymes break down substrates outside the cell so nutrients can be absorbed

Question 20

A student observes a slide under the microscope and sees round, grape-like clusters of purple cells. Which bacterial arrangement and shape is most likely being observed?

Accepted Answer

Staphylococci

Microbiology Lab Review: Labs 1–6

Study Guide - Practice Questions

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