Question 1

Which experiment provided definitive evidence that DNA is the genetic material, and what was the key finding?

Accepted Answer

Hershey and Chase's experiment with bacteriophages, showing that only DNA enters the bacterium and guides new virus formation.

Question 2

Which of the following best describes a gene?

Accepted Answer

A sequence of nucleotides in DNA encoding a functional product.

Question 3

What is the primary function of plasmids in bacterial cells?

Accepted Answer

To carry genes that may provide advantages such as antibiotic resistance.

Question 4

Which enzyme is responsible for unwinding the DNA double helix during replication?

Accepted Answer

Helicase

Question 5

In the process of transcription, which enzyme synthesizes RNA from a DNA template?

Accepted Answer

RNA polymerase

Question 6

Which of the following statements correctly compares protein synthesis in prokaryotes and eukaryotes?

Accepted Answer

Prokaryotes use formylmethionine as the first amino acid, while eukaryotes use methionine.

Question 7

Which of the following is a real-world application of recombinant DNA technology in medicine?

Accepted Answer

Production of human insulin using genetically modified bacteria.

Question 8

What is the role of a vector in recombinant DNA technology?

Accepted Answer

To transfer DNA between cells.

Question 9

Which type of gene transfer is responsible for the spread of antibiotic resistance among bacteria in the same generation?

Accepted Answer

Horizontal gene transfer

Question 10

A mutation in the DNA sequence can lead to which of the following outcomes?

Accepted Answer

Altered mRNA, altered protein, and altered function.

Question 11

Which of the following is a mutagen?

Accepted Answer

Ethylmethane sulfonate (EMS)

Question 12

What is the function of DNA polymerase during DNA replication?

Accepted Answer

Synthesizes DNA by copying a DNA template and proofreads new molecules.

Question 13

Which of the following best describes an operon?

Accepted Answer

A group of genes regulated together and transcribed as a single mRNA.

Question 14

Which of the following is a difference between inducible and repressible operons?

Accepted Answer

Inducible operons are switched 'on' by environmental inducers, while repressible operons are switched 'off' by environmental co-repressors.

Question 15

Which of the following statements about biofilms is correct?

Accepted Answer

Biofilms are produced by altered bacterial gene expression when populations are large enough.

Question 16

Which of the following is a real-world example of horizontal gene transfer leading to antibiotic resistance?

Accepted Answer

Transfer of vancomycin resistance gene via conjugative plasmid between Enterococcus faecalis and Staphylococcus aureus.

Question 17

Which of the following is a function of pilli in bacteria?

Accepted Answer

Motility (twitching and gliding) and DNA transfer (conjugation pilli).

Question 18

Which of the following statements about CRISPR is true?

Accepted Answer

CRISPR is a gene editing tool first discovered in prokaryotes as a form of immune defense against viruses.

Question 19

Which of the following is a safety or ethical concern associated with DNA technology?

Accepted Answer

Genetic testing raises questions about confidentiality and potential misuse of genetic data.

Microbial Genetics and Biotechnology: Study Notes

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