Question 1

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

Accepted Answer

Avery, MacLeod, and McCarty's experiment; they showed that purified DNA from one strain of bacteria could transform another strain.

Question 2

Which of the following best describes the structure of a DNA nucleotide?

Accepted Answer

A phosphate group, a deoxyribose sugar, and a nitrogenous base

Question 3

During DNA replication, which enzyme is responsible for adding nucleotides to the growing DNA strand?

Accepted Answer

DNA polymerase

Question 4

Which of the following statements about the genetic code is correct?

Accepted Answer

It is degenerate, meaning that multiple codons can code for the same amino acid.

Question 5

A mutation changes the codon UAU (tyrosine) to UAA. What type of mutation is this, and what is its likely effect?

Accepted Answer

Nonsense mutation; it introduces a premature stop codon, likely truncating the protein.

Question 6

Which process best describes the synthesis of an RNA molecule from a DNA template?

Accepted Answer

Transcription

Question 7

What is the main function of tRNA during translation?

Accepted Answer

To bring specific amino acids to the ribosome according to the codon sequence on mRNA

Question 8

Which of the following best explains why mutations in germ cells are more significant evolutionarily than mutations in somatic cells?

Accepted Answer

Germ cell mutations can be passed to offspring, affecting future generations.

Question 9

Which of the following is a characteristic of cancer cells?

Accepted Answer

Lack of contact inhibition, allowing uncontrolled growth

Question 10

Which enzyme is responsible for synthesizing RNA during transcription in prokaryotes?

Accepted Answer

RNA polymerase

Question 11

A scientist uses PCR (Polymerase Chain Reaction) to amplify a DNA segment. Which of the following best describes the process?

Accepted Answer

PCR uses repeated cycles of heating and cooling to denature DNA, anneal primers, and extend new DNA strands.

Question 12

Which of the following best describes a frameshift mutation?

Accepted Answer

An insertion or deletion of nucleotides that changes the reading frame of the gene

Question 13

Which of the following statements about gene regulation in prokaryotes is correct?

Accepted Answer

The lac operon is an example of negative control, where a repressor protein inhibits transcription.

Question 14

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

Accepted Answer

Producing human insulin in bacteria for diabetes treatment

Question 15

Which of the following best describes the difference between a missense and a nonsense mutation?

Accepted Answer

A missense mutation changes one amino acid, while a nonsense mutation introduces a stop codon.

Question 16

Which of the following is a function of ribosomal RNA (rRNA)?

Accepted Answer

It forms the core of the ribosome and catalyzes peptide bond formation.

Question 17

Which of the following best explains why antibiotics can target bacterial cells without harming human cells?

Accepted Answer

Antibiotics often target structures or enzymes unique to bacteria, such as peptidoglycan cell walls.

Question 18

Which of the following is a potential negative aspect of gene therapy?

Accepted Answer

Unintended effects, such as immune reactions or insertional mutagenesis

Question 19

Which of the following best describes the role of transcription factors in eukaryotic gene expression?

Accepted Answer

They bind to specific DNA sequences to regulate the initiation of transcription.

DNA Structure, Gene Expression, and Genetic Engineering: Study Notes

Study Guide - Practice Questions