Q: The central dogma of molecular genetics is best represented by which of the following sequences?

$$\text{DNA} \to \text{RNA} \to \text{Protein}$$

Q: In the classic Hershey and Chase experiment, which of the following best describes how they demonstrated that DNA is the genetic material in bacteriophages?

They labeled DNA with $$^{32}\text{P}$$ and protein with $$^{35}\text{S}$$, infected bacteria, and found that only $$^{32}\text{P}$$ entered the cells.

Question 1

Which of the following is NOT one of the five essential properties that a molecule must possess to serve as genetic material?

Accepted Answer

It must be able to catalyze metabolic reactions.

Question 2

The central dogma of molecular genetics is best represented by which of the following sequences?

Accepted Answer

$$	ext{DNA} 	o 	ext{RNA} 	o 	ext{Protein}$$

Question 3

In the classic Hershey and Chase experiment, which of the following best describes how they demonstrated that DNA is the genetic material in bacteriophages?

Accepted Answer

They labeled DNA with $$^{32}	ext{P}$$ and protein with $$^{35}	ext{S}$$, infected bacteria, and found that only $$^{32}	ext{P}$$ entered the cells.

Question 4

Which of the following is a correct statement about Chargaff's rules?

Accepted Answer

The amount of adenine equals the amount of thymine in double-stranded DNA.

Question 5

Which of the following best describes the difference between a nucleoside and a nucleotide?

Accepted Answer

A nucleotide contains a phosphate group, while a nucleoside does not.

Question 6

During DNA replication in prokaryotes, which enzyme is responsible for synthesizing new DNA strands?

Accepted Answer

DNA polymerase III

Question 7

Which of the following statements about Okazaki fragments is correct?

Accepted Answer

They are short DNA fragments synthesized on the lagging strand during DNA replication.

Question 8

A student is analyzing a DNA sample and finds that it contains 30% adenine. According to Chargaff's rules, what percentage of guanine should be present?

Accepted Answer

20%

Question 9

Which of the following best describes the function of DNA ligase during DNA replication?

Accepted Answer

It joins Okazaki fragments by forming phosphodiester bonds.

Question 10

Which of the following is a key difference between prokaryotic and eukaryotic chromosome organization?

Accepted Answer

Eukaryotic chromosomes are linear and associated with histones, while prokaryotic chromosomes are typically circular and lack histones.

Question 11

Which of the following best describes the function of topoisomerases in DNA organization?

Accepted Answer

They relieve supercoiling by cutting and rejoining DNA strands.

Question 12

Which of the following statements about the genetic code is correct?

Accepted Answer

It is degenerate, meaning that most amino acids are encoded by more than one codon.

Question 13

Which of the following is the correct start codon for translation in both prokaryotes and eukaryotes?

Accepted Answer

$$	ext{AUG}$$

Question 14

A mutation changes a codon from $$	ext{UAC} ($$tyrosine) to $$	ext{UAA}. $$What type of mutation is this?

Accepted Answer

Nonsense mutation

Question 15

Which enzyme catalyzes the formation of the peptide bond during translation?

Accepted Answer

Peptidyl transferase

Question 16

Which of the following best describes the function of the Shine-Dalgarno sequence in prokaryotes?

Accepted Answer

It helps align the ribosome with the start codon on mRNA.

Question 17

A patient is diagnosed with phenylketonuria (PKU). Which of the following best explains the genetic and biochemical basis of this disease?

Accepted Answer

A mutation in the gene encoding phenylalanine hydroxylase leads to accumulation of phenylalanine.

Question 18

Which of the following best describes the difference between introns and exons in eukaryotic genes?

Accepted Answer

Exons are coding sequences that remain in mature mRNA, while introns are non-coding sequences that are removed during RNA processing.

Question 19

Which of the following best describes the function of telomerase?

Accepted Answer

It extends the ends of linear chromosomes by adding repetitive DNA sequences.

Question 20

A researcher is studying a eukaryotic gene and finds that its promoter contains a TATA box. What is the primary function of this sequence?

Accepted Answer

It serves as a binding site for general transcription factors and RNA polymerase II.

Step-by-Step Genetics Study Guide: DNA Structure, Replication, Organization, Transcription, and Translation

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