Question 1

Which experiment provided the first direct evidence that DNA, and not protein, is the genetic material responsible for transformation in bacteria?

Accepted Answer

Oswald Avery's experiment using enzymatic destruction of DNA, RNA, and protein

Question 2

In the classic experiment by Meselson and Stahl, what was the result after one round of DNA replication in bacteria grown first in $$^{15}N$$ and then transferred to $$^{14}N$$ medium?

Accepted Answer

All DNA was hybrid (one strand $$^{15}N$$, one strand $$^{14}N)$$

Question 3

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 4

If a double-stranded DNA molecule contains 30% adenine, what percentage of guanine would you expect?

Accepted Answer

$$20\%$$

Question 5

Which of the following statements about the sugar-phosphate backbone of DNA is correct?

Accepted Answer

It is composed of alternating phosphate and deoxyribose groups

Question 6

What is the significance of the antiparallel arrangement of the two strands in a DNA double helix?

Accepted Answer

It allows the nitrogenous bases to pair correctly via hydrogen bonds

Question 7

Which of the following base pairings is consistent with the uniform width of the DNA double helix as revealed by X-ray crystallography?

Accepted Answer

Purine + pyrimidine

Question 8

Which scientist's X-ray diffraction images were critical in determining the helical structure of DNA?

Accepted Answer

Rosalind Franklin

Question 9

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

Accepted Answer

DNA polymerase

Question 10

Which of the following best explains why the mixture of heat-killed S cells and living R cells killed the mouse in Griffith's experiment?

Accepted Answer

The R cells were transformed by DNA from the S cells, becoming pathogenic

Question 11

Which of the following is NOT found in the DNA backbone?

Accepted Answer

Nitrogenous base

Question 12

What type of bond holds the two strands of DNA together between the nitrogenous bases?

Accepted Answer

Hydrogen bonds

Question 13

Which model of DNA replication was supported by the results of the Meselson-Stahl experiment?

Accepted Answer

Semiconservative model

Question 14

If a DNA molecule is 100 base pairs long and contains 40 adenine bases, how many guanine bases does it contain?

Accepted Answer

$$10$$

Question 15

Which of the following statements about DNA replication is correct?

Accepted Answer

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

Question 16

Which of the following is a real-world application of understanding DNA replication?

Accepted Answer

Forensic DNA fingerprinting

Question 17

Which of the following best describes Chargaff's rules?

Accepted Answer

In any species, the amount of adenine equals the amount of thymine, and the amount of guanine equals the amount of cytosine

Question 18

Which of the following would be the result if DNA replication were conservative instead of semiconservative?

Accepted Answer

One DNA molecule would have both old strands, and the other would have both new strands

Question 19

Which of the following is a correct statement about the directionality of DNA strands?

Accepted Answer

The two strands run antiparallel, with one running 5' to 3' and the other 3' to 5'

Question 20

Which of the following best explains why DNA replication is essential for cell division?

Accepted Answer

It ensures that each daughter cell receives an exact copy of the genetic material

Chapter 16: The Molecular Basis of Inheritance – DNA Structure, Function, and Replication part 1

Guida di studio - Domande di pratica

Study guide - Flashcard