Question 1

Which experiment provided the strongest evidence that DNA, and not protein, is the genetic material in viruses that infect bacteria?

Accepted Answer

The Hershey-Chase experiment using radioactive tracers

Question 2

According to Chargaff's rules, if a DNA sample contains 30% adenine, what percentage of guanine would you expect to find?

Accepted Answer

$$20\%$$

Question 3

Which of the following best describes the structure of DNA as revealed by Watson and Crick?

Accepted Answer

A double helix with complementary base pairing and hydrogen bonds between bases

Question 4

During DNA replication, which enzyme is responsible for unwinding the double helix?

Accepted Answer

Helicase

Question 5

In eukaryotic cells, DNA replication begins at multiple origins of replication. What is the significance of this for the cell?

Accepted Answer

It allows for faster and more efficient replication of large genomes

Question 6

Which of the following is a key difference between DNA and RNA?

Accepted Answer

DNA is double-stranded, while RNA is single-stranded

Question 7

A mutation prevents the removal of introns from pre-mRNA in a eukaryotic cell. What is the most likely consequence?

Accepted Answer

The resulting protein may be nonfunctional due to incorrect amino acid sequence

Question 8

Which process describes the flow of genetic information from DNA to RNA to protein?

Accepted Answer

Central dogma of molecular biology

Question 9

In the lac operon of E. coli, what happens when lactose is present?

Accepted Answer

Lactose binds to the repressor, inactivating it and allowing transcription

Question 10

Which of the following best explains why red blood cells only produce hemoglobin when heme is available?

Accepted Answer

Gene expression is regulated at the level of mRNA translation by environmental conditions

Question 11

A scientist discovers a eukaryotic gene that can produce multiple different proteins. Which mechanism most likely explains this observation?

Accepted Answer

Alternative mRNA splicing

Question 12

Which of the following is true about the role of tRNA during translation?

Accepted Answer

tRNA brings specific amino acids to the ribosome based on its anticodon

Question 13

If a mutation causes a transcription factor to be nonfunctional in a eukaryotic cell, what is a likely outcome?

Accepted Answer

RNA polymerase will not bind efficiently to the promoter, reducing gene expression

Question 14

Which of the following best describes semiconservative replication?

Accepted Answer

Each new DNA molecule consists of one parental and one new strand

Question 15

Which of the following is a real-world example of gene regulation in prokaryotes?

Accepted Answer

E. coli producing enzymes to metabolize lactose only when lactose is present

Question 16

Which of the following equations correctly represents the complementary base pairing in DNA?

Accepted Answer

$$[A] = [T]$$ and $$[G] = [C]$$

Question 17

Which of the following is NOT a function of ribosomal RNA (rRNA)?

Accepted Answer

Carries amino acids to the ribosome

Question 18

A mutation in the operator region of the lac operon prevents the repressor from binding. What is the most likely result?

Accepted Answer

The genes for lactose metabolism will be transcribed continuously, even without lactose

Question 19

Which of the following best explains why chromatin condensation can regulate gene expression in eukaryotes?

Accepted Answer

Tightly packed chromatin prevents transcription factors and RNA polymerase from accessing DNA

Question 20

Which of the following steps occurs during the elongation phase of translation?

Accepted Answer

A peptide bond forms between amino acids as the polypeptide chain lengthens

Chapter 11: The Instructions for Life – DNA and RNA (Structure, Function, and Gene Expression)

Study Guide - Practice Questions