Question 1

Which of the following best describes the central dogma of molecular biology?

Accepted Answer

Information flows from DNA to RNA to protein.

Question 2

What is the role of RNA polymerase during transcription?

Accepted Answer

It unwinds DNA and adds RNA nucleotides to synthesize RNA from a DNA template.

Question 3

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

Accepted Answer

Prokaryotic transcription and translation occur simultaneously, while eukaryotic transcription is separated from translation by the nuclear envelope.

Question 4

A mutation changes a codon from $$\mathrm{GAA} ($$glutamic acid) to $$\mathrm{GUA} ($$valine). What type of mutation is this?

Accepted Answer

Missense mutation

Question 5

Which enzyme is responsible for attaching amino acids to tRNA molecules during translation?

Accepted Answer

Aminoacyl tRNA synthetase

Question 6

What is the function of the spliceosome in eukaryotic cells?

Accepted Answer

It removes introns from pre-mRNA transcripts.

Question 7

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

Accepted Answer

It is redundant, meaning multiple codons can code for the same amino acid.

Question 8

A scientist discovers a virus that uses reverse transcriptase. What does this enzyme do?

Accepted Answer

It synthesizes DNA from an RNA template.

Question 9

Which of the following is NOT a modification that occurs to eukaryotic pre-mRNA before it becomes mature mRNA?

Accepted Answer

Removal of exons

Question 10

During translation, which ribosomal site does the incoming aminoacyl-tRNA first bind?

Accepted Answer

A site

Question 11

Which of the following best explains why silent mutations do not affect the protein sequence?

Accepted Answer

Because of the redundancy in the genetic code, multiple codons can code for the same amino acid.

Question 12

What is the consequence of a frameshift mutation in a gene?

Accepted Answer

It alters the reading frame, potentially changing every amino acid downstream of the mutation.

Question 13

Which of the following is a real-world example of a missense mutation?

Accepted Answer

Sickle cell anemia, caused by a single base substitution in the hemoglobin gene.

Question 14

Which statement about ribosomes is correct?

Accepted Answer

Eukaryotic ribosomes have 60S and 40S subunits, while prokaryotic ribosomes have 50S and 30S subunits.

Question 15

Which of the following is an exception to the central dogma?

Accepted Answer

Some genes make RNA that is not translated into protein, such as tRNA and rRNA.

Question 16

What is the function of chaperone proteins in the cell?

Accepted Answer

They help newly synthesized proteins fold into their correct three-dimensional shape.

Question 17

Which process requires the most energy in the form of phosphate bonds per peptide bond formed?

Accepted Answer

Translation

Question 18

Which of the following statements about tRNA is TRUE?

Accepted Answer

Each tRNA carries a specific amino acid and has an anticodon that pairs with the mRNA codon.

Question 19

In eukaryotes, what is the role of the TATA box in transcription?

Accepted Answer

It is a DNA sequence in the promoter region that helps position RNA polymerase II for transcription initiation.

Question 20

Which of the following best explains why multiple RNA transcripts can be made from a single gene?

Accepted Answer

RNA polymerase can repeatedly bind to the promoter and initiate transcription, allowing for continuous production of RNA.

Gene Expression, Transcription, and Translation: Molecular Basis of Protein Synthesis

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