Question 1

Which experiment provided the most direct evidence that DNA, and not protein, is the genetic material in phages?

Accepted Answer

Hershey-Chase experiment using radioactive isotopes

Question 2

Which of the following best describes the structure of a nucleosome?

Accepted Answer

An octamer of histones wrapped by 147 bp of DNA

Question 3

Which of the following is NOT a difference between DNA and RNA?

Accepted Answer

DNA contains phosphodiester bonds, RNA does not

Question 4

A segment of DNA has the following base composition: 30% adenine, 20% guanine, 20% cytosine, and 30% thymine. Which rule does this composition follow?

Accepted Answer

Chargaff's first parity rule

Question 5

Which of the following best explains why DNA supercoiling is important in bacterial chromosomes?

Accepted Answer

It compacts the DNA to fit inside the cell

Question 6

Which enzyme is primarily responsible for introducing or removing supercoils in DNA?

Accepted Answer

Topoisomerase

Question 7

A mutation causes the loss of function in histone H1. Which of the following chromatin structures would be most directly affected?

Accepted Answer

The 30-nm chromatin fiber

Question 8

Which of the following modifications is most closely associated with gene activation in eukaryotic chromatin?

Accepted Answer

Histone acetylation

Question 9

Which of the following best describes the role of scaffold proteins in chromosomes?

Accepted Answer

They stabilize supercoiled chromatin and provide structural support

Question 10

A DNA palindrome is best described as:

Accepted Answer

A sequence that reads the same 5' to 3' on both strands

Question 11

Which of the following is a function of nonhistone proteins in chromatin?

Accepted Answer

Acting as chromosome scaffold and participating in transcription

Question 12

Which of the following statements about repetitive DNA in eukaryotic genomes is correct?

Accepted Answer

Moderately repetitive DNA includes rRNA genes and microsatellites

Question 13

A scientist isolates a DNA molecule and finds that it is circular, double-stranded, and associated with HU and H-NS proteins. This DNA most likely comes from:

Accepted Answer

A bacterial chromosome

Question 14

Which of the following best describes the chemical linkage between nucleotides in a DNA strand?

Accepted Answer

Phosphodiester bond between the 3' hydroxyl and 5' phosphate

Question 15

If a double-stranded DNA molecule contains 22% guanine, what is the percentage of thymine?

Accepted Answer

$$28\%$$

Question 16

Which of the following is a real-world application of microsatellite DNA (STRs)?

Accepted Answer

DNA fingerprinting in forensic science

Question 17

Which of the following best explains why mitochondrial DNA does not follow Chargaff's second parity rule?

Accepted Answer

It is inherited maternally and has a unique replication mechanism

Question 18

Which of the following is true about the central dogma of molecular biology?

Accepted Answer

Information flows from DNA to RNA to protein

Question 19

A patient is found to have a mutation in a gene that encodes a noncoding RNA. Which of the following is a possible function of this gene product?

Accepted Answer

Regulating gene expression as a microRNA

Question 20

Which of the following best describes the difference between heterochromatin and euchromatin?

Accepted Answer

Heterochromatin is more condensed and less transcriptionally active than euchromatin

Lecture 8 (ch10&12)

Guida di studio - Domande di pratica

Study guide - Flashcard