Question 1

Which experiment provided the first direct evidence that DNA is the genetic material responsible for transformation in bacteria?

Accepted Answer

Frederick Griffith's experiment with Streptococcus pneumoniae

Question 2

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

Accepted Answer

$$20\%$$

Question 3

Which of the following best explains why DNA polymerase can only add nucleotides to the 3' end of a growing DNA strand?

Accepted Answer

The 3' hydroxyl group is required for the formation of a phosphodiester bond

Question 4

A scientist is studying a eukaryotic cell line that divides rapidly and shows high telomerase activity. What is the most likely consequence of this observation?

Accepted Answer

The cells may become cancerous due to unlimited cell division

Question 5

Which enzyme is responsible for relieving the strain caused by unwinding of the DNA double helix during replication?

Accepted Answer

Topoisomerase

Question 6

During DNA replication, which strand is synthesized in short fragments and what are these fragments called?

Accepted Answer

Lagging strand; Okazaki fragments

Question 7

A mutation occurs that disables the function of DNA ligase in a cell. What is the most likely result during DNA replication?

Accepted Answer

Okazaki fragments on the lagging strand will not be joined together

Question 8

Which of the following best describes the semiconservative model of DNA replication?

Accepted Answer

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

Question 9

Which of the following is NOT a function of histone proteins in eukaryotic cells?

Accepted Answer

Catalyzing the synthesis of DNA

Question 10

A patient is exposed to high levels of X-rays, which cause DNA damage. Which DNA repair mechanism is most likely to be activated to remove and replace damaged DNA segments?

Accepted Answer

Nucleotide excision repair

Question 11

Which of the following statements about euchromatin and heterochromatin is correct?

Accepted Answer

Euchromatin is loosely packed and generally accessible for transcription

Question 12

Which of the following best explains why prokaryotes do not experience telomere shortening during DNA replication?

Accepted Answer

Their chromosomes are circular, so there are no ends to shorten

Question 13

Which of the following is a direct consequence of the antiparallel structure of DNA during replication?

Accepted Answer

One strand is synthesized continuously, while the other is synthesized in fragments

Question 14

A researcher finds a eukaryotic cell with a mutation that prevents the formation of nucleosomes. Which of the following is the most likely effect?

Accepted Answer

DNA will not be efficiently packed into the nucleus

Question 15

Which of the following best describes the role of primase during DNA replication?

Accepted Answer

It synthesizes a short RNA primer to provide a starting point for DNA polymerase

Question 16

If a DNA molecule is composed of 18% cytosine, what is the percentage of thymine in the molecule?

Accepted Answer

$$32\%$$

Question 17

Which of the following is a real-world example of a mutation caused by a failure in DNA repair mechanisms?

Accepted Answer

Sickle cell anemia caused by a point mutation in the hemoglobin gene

Question 18

Which of the following statements about the structure of DNA is correct?

Accepted Answer

The two strands are held together by hydrogen bonds between complementary bases

Question 19

Which of the following best explains the evolutionary significance of mutations in DNA?

Accepted Answer

They are the source of genetic variation upon which natural selection acts

Chapter 16: The Molecular Basis of Inheritance – Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard