Question 1

Which of the following best describes the Sanger method for DNA sequencing?

Accepted Answer

It uses dideoxynucleotides to terminate DNA synthesis at specific bases, generating fragments that can be separated by size.

Question 2

Which of the following statements correctly compares a metagenome to a genome?

Accepted Answer

A metagenome is the collective genetic material from an entire microbial community, while a genome is the genetic material of a single organism.

Question 3

Which eukaryotic organelles contain their own genomes, supporting the endosymbiotic theory?

Accepted Answer

Mitochondria and chloroplasts

Question 4

Which of the following best describes the difference between a proteome and a transcriptome?

Accepted Answer

A proteome is the entire set of proteins expressed by a cell, while a transcriptome is the entire set of RNA transcripts.

Question 5

During PCR, which of the following steps is responsible for the specificity of DNA amplification?

Accepted Answer

Annealing of primers to complementary sequences

Question 6

Which of the following is a key difference between traditional PCR and RT-PCR?

Accepted Answer

RT-PCR uses reverse transcriptase to convert RNA into cDNA before amplification.

Question 7

A researcher wants to separate DNA fragments by size after PCR. Which method should they use?

Accepted Answer

Gel electrophoresis

Question 8

In the pUC19 cloning vector system, how are bacterial transformants that have successfully taken up foreign DNA typically identified?

Accepted Answer

By loss of blue color on X-gal plates due to disruption of the lacZ gene

Question 9

Which of the following best describes the T7 expression system used in molecular cloning?

Accepted Answer

It uses a T7 RNA polymerase gene under control of a lac promoter to drive high-level expression of a target gene.

Question 10

Which gene is most commonly targeted for bacterial phylogenetic analysis and why?

Accepted Answer

16S rRNA gene, because it is highly conserved and present in all bacteria

Question 11

Which bacterial phylum is considered the largest and most metabolically diverse?

Accepted Answer

Proteobacteria

Question 12

In a microbial community, what is the difference between species richness and species abundance?

Accepted Answer

Richness is the number of different species present, while abundance is the proportion of each species.

Question 13

Which of the following best describes a biofilm and its significance in medicine?

Accepted Answer

A biofilm is a structured community of microorganisms attached to a surface, often resistant to antibiotics and associated with chronic infections.

Question 14

Which of the following marine phototrophs is a cyanobacterium and a major contributor to global primary production?

Accepted Answer

Prochlorococcus

Question 15

Which process is primarily responsible for the largest release of $$CO_2 to $$the atmosphere?

Accepted Answer

Microbial respiration in soils

Question 16

Which of the following best explains how the carbon and nitrogen cycles are coupled in the environment?

Accepted Answer

Microbial processes such as decomposition and nitrification require both carbon and nitrogen substrates.

Question 17

Which of the following symbioses is correctly matched with its classification?

Accepted Answer

Lichen – mutualism

Question 18

What is the significance of leghemoglobin in the legume-root nodule symbiosis?

Accepted Answer

It binds oxygen to protect nitrogenase from inactivation, allowing efficient nitrogen fixation.

Question 19

Which organism is commonly found in the human stomach and is associated with gastric ulcers and cancer?

Accepted Answer

Helicobacter pylori

Question 20

A patient with recurrent Clostridioides difficile infection is treated with a fecal transplant. What is the primary purpose of this treatment?

Accepted Answer

To restore a healthy gut microbiome and outcompete the pathogen

MCB3020 Final Exam Study Guide – Microbiology Concepts and Practice Questions

Study Guide - Practice Questions