Question 1

Which of the following statements best explains why viruses are not considered living organisms?

Accepted Answer

They lack cellular structure and cannot carry out metabolism on their own.

Question 2

A microbiologist is culturing bacteria on blood agar and observes a clear, colorless zone around the colonies. What type of hemolysis is this, and what does it indicate?

Accepted Answer

Beta hemolysis; complete lysis of red blood cells.

Question 3

Which of the following best describes the difference between binary fission and multiple fission (schizogony)?

Accepted Answer

Binary fission results in two identical cells, while schizogony results in multiple daughter cells from a single parent cell.

Question 4

Which of the following is a unique feature of Mycobacterium species?

Accepted Answer

They have a waxy cell wall rich in mycolic acids, making them acid-fast.

Question 5

During the lytic cycle of a bacteriophage, which of the following steps occurs immediately after the viral genome enters the host cell?

Accepted Answer

Biosynthesis of viral components using host machinery.

Question 6

Which of the following best describes the ploidy changes during mitosis and meiosis in eukaryotic cells?

Accepted Answer

Mitosis maintains the ploidy number, while meiosis halves it.

Question 7

A scientist is working with a +pGLO plasmid and plates transformed E. coli on LB/AMP/ARA agar. What result should be expected and why?

Accepted Answer

Growth with green fluorescence, because arabinose induces GFP expression and ampicillin resistance allows survival.

Question 8

Which of the following statements about archaea is correct?

Accepted Answer

Archaea often thrive in extreme environments such as high salinity or temperature.

Question 9

Which enzyme is detected by the catalase test, and what is the chemical reaction involved?

Accepted Answer

Catalase; $$ 2\mathrm{H}_2\mathrm{O}_2 \rightarrow 2\mathrm{H}_2\mathrm{O} + \mathrm{O}_2 $$

Question 10

Which of the following best describes the alternation of generations in algae?

Accepted Answer

A life cycle that alternates between haploid and diploid multicellular stages.

Question 11

Which of the following is true about the envelope of some viruses?

Accepted Answer

It is derived from the host cell membrane during viral release.

Question 12

Which of the following statements about prions is correct?

Accepted Answer

Prions are infectious proteins that lack nucleic acids.

Question 13

A patient is diagnosed with a viral infection. The virus has a +ssRNA genome. Which of the following best describes how this genome is processed in a eukaryotic host cell?

Accepted Answer

The +ssRNA is directly translated by host ribosomes into viral proteins.

Question 14

Which of the following is a characteristic of alveolates among protozoans?

Accepted Answer

They possess membrane-bound sacs (alveoli) beneath their plasma membrane.

Question 15

Which of the following best explains why the streak-stab technique is used on blood agar?

Accepted Answer

To test for anaerobic hemolysis by creating an oxygen gradient.

Question 16

Which of the following statements about the oxidase test is correct?

Accepted Answer

A positive result is indicated by a color change on a test strip due to cytochrome c oxidase activity.

Question 17

Which of the following is a key difference between prokaryotes and eukaryotes?

Accepted Answer

Eukaryotes have a nucleus containing their genetic material, while prokaryotes do not.

Question 18

Which of the following best describes a viroid?

Accepted Answer

A small, circular RNA molecule that infects plants and lacks a protein coat.

Question 19

Which of the following is true about the ELISA technique?

Accepted Answer

It is used to detect the presence of specific antigens or antibodies in a sample.

Question 20

Which of the following is a unique feature of cyanobacteria?

Accepted Answer

They are photosynthetic prokaryotes that produce oxygen.

Question 21

Which of the following best describes the role of the ampicillin resistance gene on the pGLO plasmid in a transformation experiment?

Accepted Answer

It allows transformed bacteria to grow in the presence of ampicillin.

Microbiology Study Guide: Prokaryotes, Eukaryotes, Viruses, and Laboratory Techniques

Study Guide - Practice Questions

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