Question 1

Which of the following best describes the role of RNA polymerase during transcription in eukaryotic cells?

Accepted Answer

It unwinds the DNA double helix and synthesizes a complementary RNA strand from the DNA template.

Question 2

A mutation changes a single base in a gene, resulting in the codon GAA being changed to GUA in the mRNA. Using the codon table, what is the consequence of this mutation?

Accepted Answer

The amino acid glutamic acid (Glu) is replaced by valine (Val), which may alter protein function.

Question 3

Which of the following statements about introns and exons is correct?

Accepted Answer

Introns are removed from the primary RNA transcript, while exons are joined together to form functional mRNA.

Question 4

During translation, what is the function of the tRNA molecule?

Accepted Answer

It brings the correct amino acid to the ribosome by matching its anticodon to the mRNA codon.

Question 5

Which of the following best describes the primary structure of a protein?

Accepted Answer

The specific sequence of amino acids held together by peptide bonds.

Question 6

A patient has a genetic disorder caused by a single amino acid substitution in hemoglobin. Which level of protein structure is directly affected by this mutation?

Accepted Answer

Primary structure

Question 7

Which of the following events occurs during the elongation stage of translation?

Accepted Answer

Amino acids are added one by one to the growing polypeptide chain as tRNAs bring them to the ribosome.

Question 8

Which codon serves as the universal start signal for translation, and which amino acid does it code for?

Accepted Answer

AUG; Methionine

Question 9

What is the role of ribozymes during RNA processing in eukaryotic cells?

Accepted Answer

They catalyze the removal of introns from the primary RNA transcript.

Question 10

A scientist isolates a segment of mRNA with the sequence 5'-AUG GGC UUU UGA-3'. Using the codon table, what is the resulting amino acid sequence?

Accepted Answer

Methionine-Glycine-Phenylalanine

Question 11

Which of the following best explains why multiple codons can code for the same amino acid?

Accepted Answer

The genetic code is redundant, allowing for some variation in the third base of the codon.

Question 12

Which of the following is NOT a function of rRNA in the ribosome?

Accepted Answer

Carrying amino acids to the ribosome

Question 13

If a stop codon is introduced prematurely into an mRNA sequence, what is the most likely outcome?

Accepted Answer

A truncated, nonfunctional protein will be produced.

Question 14

Which of the following best describes the quaternary structure of a protein?

Accepted Answer

The association of multiple polypeptide chains to form a functional protein.

Question 15

Which process occurs in the cytoplasm and involves the conversion of mRNA code into a polypeptide chain?

Accepted Answer

Translation

Question 16

A protein is found to have a defect in its tertiary structure. Which of the following is most likely to be affected?

Accepted Answer

The overall three-dimensional folding and function of the protein.

Question 17

Which of the following is true regarding the flow of genetic information in a eukaryotic cell?

Accepted Answer

$$DNA \rightarrow mRNA \rightarrow Protein$$

Question 18

Which of the following is a real-life example of the importance of correct protein synthesis?

Accepted Answer

A single amino acid change in hemoglobin causes sickle cell anemia.

Protein Synthesis: Transcription, Translation, and Protein Structure

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