Question 1

Which of the following statements best describes the theory of biogenesis?

Accepted Answer

Living organisms arise from preexisting living cells.

Question 2

A patient presents with a fungal infection after prolonged antibiotic use. Which property of fungi most likely contributed to their ability to thrive in this situation?

Accepted Answer

Fungi are eukaryotic and can metabolize complex carbohydrates.

Question 3

Which of the following best explains why Gram-negative bacteria are generally more resistant to antibiotics that target the cell wall?

Accepted Answer

They possess an outer membrane that restricts entry of many antibiotics.

Question 4

A scientist discovers a new microorganism with the following characteristics: it has a nucleus, mitochondria, and a cell wall made of chitin. To which group does this organism most likely belong?

Accepted Answer

Fungi

Question 5

Which of the following is a correct application of binomial nomenclature for naming microorganisms?

Accepted Answer

Escherichia coli

Question 6

A patient is diagnosed with a disease caused by a nematode. Which of the following best describes the organism responsible?

Accepted Answer

A roundworm with a complete digestive system

Question 7

Which of the following structures is found in both prokaryotic and eukaryotic cells and is responsible for protein synthesis?

Accepted Answer

Ribosomes

Question 8

A virus is classified as an RNA virus. Which of the following statements is true regarding its genetic material?

Accepted Answer

It contains single- or double-stranded RNA as its genome.

Question 9

Which of the following best describes the process of conjugation in bacteria?

Accepted Answer

Direct transfer of plasmid DNA through a pilus

Question 10

A patient is infected with a protozoan that alternates between a trophozoite and a cyst stage. What is the primary advantage of the cyst stage for the protozoan?

Accepted Answer

It provides protection from harsh environmental conditions.

Question 11

Which of the following best explains why prions are unique among infectious agents?

Accepted Answer

They are composed solely of protein and lack nucleic acids.

Question 12

A mutation changes the codon UAU (tyrosine) to UAA (stop codon). What type of mutation is this?

Accepted Answer

Nonsense mutation

Question 13

Which of the following best describes the lytic cycle of a bacteriophage?

Accepted Answer

The virus immediately replicates and lyses the host cell.

Question 14

A patient is diagnosed with a persistent viral infection. Which of the following best characterizes this type of infection?

Accepted Answer

The virus remains in the host for long periods, often with ongoing production of low levels of virus.

Question 15

Which of the following equations correctly represents the calculation of total magnification in a compound light microscope?

Accepted Answer

$$	ext{Total Magnification} = 	ext{Objective Lens Magnification} 	imes 	ext{Ocular Lens Magnification}$$

Question 16

Which of the following is a medically important arthropod vector and the disease it transmits?

Accepted Answer

Mosquito – Plasmodium (malaria)

Question 17

A bacterial cell is exposed to a chemical mutagen that causes the insertion of a single nucleotide into a gene. What is the most likely result of this mutation?

Accepted Answer

Frameshift mutation

Question 18

Which of the following best describes the function of endospores in bacteria?

Accepted Answer

They allow bacteria to survive extreme environmental conditions.

Question 19

A scientist is studying a eukaryotic cell and observes the presence of a glycocalyx. What is the primary function of the glycocalyx in eukaryotic cells?

Accepted Answer

Protection and cell-to-cell recognition

Question 20

Which of the following best explains why viruses are not classified as living organisms?

Accepted Answer

They lack a cell structure and cannot carry out metabolism independently.

BIO 225 Unit 1: Microbiology Study Guide

Study Guide - Practice Questions

Study Guide - Flashcards