Question 1

Which of the following best explains why DNA, and not protein, was ultimately identified as the genetic material in the Hershey–Chase experiment?

Accepted Answer

Radioactively labeled DNA entered the bacterial cell and directed viral reproduction, while labeled protein did not.

Question 2

A mutation occurs in the DNA of a gamete, resulting in a change in the sequence of bases. According to the central dogma, what is the most likely consequence of this mutation?

Accepted Answer

The mutation will be reflected in the RNA and may alter the resulting protein.

Question 3

Which of the following is NOT a characteristic required for a molecule to serve as genetic material?

Accepted Answer

Ability to catalyze metabolic reactions

Question 4

In the Avery, MacLeod, and McCarty experiment, which treatment destroyed the transforming principle and prevented transformation of avirulent bacteria?

Accepted Answer

Treatment with DNase

Question 5

Which of the following statements about Chargaff’s rules is CORRECT?

Accepted Answer

The sum of purines (A + G) equals the sum of pyrimidines (C + T).

Question 6

A DNA molecule is subjected to increasing temperature, and its absorption of UV light at 260 nm is measured. What is the term for the increase in absorption observed as the DNA denatures?

Accepted Answer

Hyperchromic shift

Question 7

Which of the following best describes the chemical difference between DNA and RNA sugars?

Accepted Answer

DNA contains deoxyribose, which has a hydrogen at the 2' position; RNA contains ribose, which has a hydroxyl group at the 2' position.

Question 8

Which of the following equations correctly represents the base-pairing rule in double-stranded DNA?

Accepted Answer

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

Question 9

A researcher isolates a nucleic acid from a virus and finds that it contains uracil, is single-stranded, and can serve as a template for reverse transcription. What type of virus is this most likely to be?

Accepted Answer

A retrovirus

Question 10

Which analytical technique would be most appropriate for separating DNA fragments of different lengths generated during a forensic investigation?

Accepted Answer

Nucleic acid electrophoresis

Question 11

Which of the following best describes the structure of B-DNA as proposed by Watson and Crick?

Accepted Answer

A right-handed double helix with antiparallel strands and base pairs perpendicular to the axis

Question 12

Which of the following is a direct piece of evidence supporting DNA as the genetic material in eukaryotes?

Accepted Answer

Recombinant DNA technology allows bacterial cells to produce human proteins, such as insulin.

Question 13

A scientist is using fluorescent probes to detect the presence of a specific DNA sequence on human chromosomes. Which technique is being used?

Accepted Answer

Fluorescent in situ hybridization (FISH)

Question 14

Which of the following statements about phosphodiester bonds in nucleic acids is CORRECT?

Accepted Answer

They connect the 3' hydroxyl group of one sugar to the 5' phosphate group of the next sugar.

Question 15

Which of the following best explains why UV light at 260 nm is particularly effective at inducing mutations in DNA?

Accepted Answer

DNA absorbs UV light most strongly at 260 nm, which matches the action spectrum for mutagenesis.

Question 16

Which of the following is a unique RNA molecule involved in the replication of chromosome ends in eukaryotes?

Accepted Answer

Telomerase RNA

Question 17

A DNA sample is found to have a higher melting temperature ($$T_m) $$than another sample. What can you conclude about its base composition?

Accepted Answer

It has a higher proportion of guanine and cytosine.

Question 18

Which of the following best describes the role of ATP and GTP in the cell?

Accepted Answer

They are nucleoside triphosphates that serve as energy sources and precursors for nucleic acid synthesis.

Question 19

Which alternative DNA conformation is characterized by a left-handed double helix and a zig-zag backbone?

Accepted Answer

Z-DNA

DNA Structure and Analysis: Study Notes for Genetics Students

Guida di studio - Domande di pratica

Study guide - Flashcard