Question 1

Which of the following best describes the difference between serum and plasma in blood?

Accepted Answer

Serum is the liquid portion of blood after clotting, while plasma is the liquid portion before clotting.

Question 2

A scientist is comparing a bacterial cell and a human cell under a microscope. Which of the following features is found in the human cell but NOT in the bacterial cell?

Accepted Answer

Nucleus

Question 3

Which of the following statements about Gram-positive and Gram-negative bacteria is correct?

Accepted Answer

Gram-positive bacteria have a thick peptidoglycan layer and no outer membrane.

Question 4

Arrange the following microorganisms from smallest to largest: virus, bacterium, yeast, protozoan.

Accepted Answer

Virus \u003c Bacterium \u003c Yeast \u003c Protozoan

Question 5

Convert $$2.5$$ milligrams $$(mg) to $$nanograms $$(ng). $$Use the following conversions: $$1 mg = 10^3$ \ \mu g$$, $$1 \mu g = 10^3$ ng.$$

Accepted Answer

$$2.5 	imes 10^6$ ng

Question 6

After performing a Gram stain, a student observes purple, spherical bacteria arranged in clusters. What is the correct description for these bacteria?

Accepted Answer

Gram-positive staphylococci

Question 7

During fermentation, which of the following is a common byproduct produced by bacteria?

Accepted Answer

Lactic acid

Question 8

Where is the electron transport chain located in prokaryotic (bacterial) cells?

Accepted Answer

Cytoplasmic membrane

Question 9

Which of the following best describes an exergonic reaction?

Accepted Answer

A reaction that releases energy

Question 10

A bacterium that grows best at pH 2 and at a temperature of 60°C is best described as:

Accepted Answer

Acidophile and thermophile

Question 11

Which enzyme is responsible for breaking down hydrogen peroxide $$(H_2O_2)$$ into water and oxygen in bacteria?

Accepted Answer

Catalase

Question 12

Which process allows bacteria to sense their population density and coordinate gene expression accordingly?

Accepted Answer

Quorum sensing

Question 13

Which of the following base pairs is correctly matched in a DNA double helix?

Accepted Answer

Adenine–Thymine

Question 14

A scientist wants to transfer a gene from one bacterium to another using a bacteriophage. Which method of genetic exchange is being used?

Accepted Answer

Transduction

Question 15

What is the main function of restriction endonucleases in genetic engineering?

Accepted Answer

To cut DNA at specific sequences

Question 16

Which of the following best describes the purpose of the polymerase chain reaction (PCR)?

Accepted Answer

To amplify specific DNA sequences

Question 17

Which of the following is the most effective means of sterilizing surgical equipment?

Accepted Answer

Autoclaving at $$121^\circ C$$ for 15 minutes

Question 18

A laboratory technician is asked to inject 1 mg of penicillin to a patient. The available vial contains 10 mg/ml penicillin in a 5 ml suspension. What volume should be administered?

Accepted Answer

$$1 \div 10 = 0.1 ml$$

Question 19

Which scientist is credited with the discovery of penicillin?

Accepted Answer

Alexander Fleming

Question 20

A set of test tubes contains increasing concentrations of Antibiotic X: 0.5, 1, 2, 4, 8, and 16 $$\mu g/ml. $$After incubation, tubes with 0.5, 1, and 2 $$\mu g/ml$$ show growth, but those with 4, 8, and 16 $$\mu g/ml do $$not. What is the minimum inhibitory concentration (MIC) of Antibiotic X?

Accepted Answer

4 $$\mu g/ml$$

Microbiology Midterm Study Guide: Key Concepts and Applications (Chapters 1, 3, 4, 5, 6, 7, 8, 9, 10, 11)

Study Guide - Practice Questions

Study Guide - Flashcards