Question 1

Which of the following best describes the flow of genetic information according to the central dogma of molecular biology?

Accepted Answer

DNA is transcribed into mRNA, which is then translated into a specific sequence of amino acids.

Question 2

During transcription, which enzyme is responsible for synthesizing the mRNA strand from the DNA template?

Accepted Answer

RNA polymerase II

Question 3

Which of the following sequences correctly represents the phases of transcription and a key event in each?

Accepted Answer

Initiation: transcription factors bind to the gene; Elongation: RNA polymerase II adds complementary nucleotides; Termination: the enzyme falls off the gene

Question 4

What is the primary function of the 5' cap and poly-A tail added during RNA processing?

Accepted Answer

To protect mRNA from degradation and assist in transport out of the nucleus

Question 5

A scientist inserts a firefly gene into a tobacco plant. Which property of the genetic code allows the plant to produce the firefly protein?

Accepted Answer

The genetic code is universal, so the plant can transcribe and translate the firefly gene.

Question 6

Which of the following best describes the role of tRNA during translation?

Accepted Answer

tRNA acts as a molecular interpreter, matching amino acids to codons on the mRNA.

Question 7

A mutation changes a single nucleotide in a gene, resulting in a different amino acid in the protein. What type of mutation is this?

Accepted Answer

Point mutation

Question 8

Which of the following is a potential benefit of mutations in a population?

Accepted Answer

They can introduce genetic variation that may be beneficial for evolution.

Question 9

During translation, which sequence of events occurs during the elongation phase?

Accepted Answer

Codon recognition, peptide bond formation, translocation

Question 10

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

Accepted Answer

Exons are joined together to form the mature mRNA, while introns are removed.

Question 11

A mutation causes a nucleotide to be inserted into a gene, shifting the reading frame. What is this type of mutation called?

Accepted Answer

Frameshift mutation

Question 12

Which of the following best explains why not all mutations are harmful?

Accepted Answer

Some mutations do not change the amino acid sequence or may even improve an organism's survival.

Question 13

Which of the following is NOT a step in the process of transcription?

Accepted Answer

Translocation

Question 14

Which of the following best describes a codon?

Accepted Answer

A triplet of bases on mRNA that codes for a specific amino acid

Question 15

Which of the following is a direct result of errors during DNA replication or exposure to mutagens?

Accepted Answer

Mutations

Question 16

Which of the following best explains the importance of the promoter region in transcription?

Accepted Answer

It signals where RNA polymerase II should bind to initiate transcription.

Question 17

A patient is exposed to a chemical mutagen that causes random insertions and deletions in their DNA. Which type of mutation is most likely to occur?

Accepted Answer

Frameshift mutation

Question 18

Which of the following is a correct description of the role of ribosomes in protein synthesis?

Accepted Answer

Ribosomes make polypeptides by facilitating the joining of amino acids during translation.

Question 19

Which of the following best describes the relationship between the genetic code and protein synthesis?

Accepted Answer

The genetic code determines the sequence of amino acids in a protein by specifying which codons correspond to which amino acids.

Protein Synthesis: From Gene to Protein

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