Question 1

Which of the following best describes the flow of genetic information in a eukaryotic cell, according to the central dogma of molecular biology?

Accepted Answer

DNA $$\rightarrow$$ RNA $$\rightarrow$$ Protein

Question 2

During transcription in eukaryotic cells, which enzyme is responsible for synthesizing the RNA strand from the DNA template?

Accepted Answer

RNA polymerase

Question 3

A mutation changes a codon from $$	ext{GAA} to$$ $$	ext{GAG}$$, but both codons specify the amino acid glutamic acid. What is this phenomenon called, and why does it occur?

Accepted Answer

Silent mutation; because the genetic code is redundant

Question 4

Which of the following structural differences between DNA and RNA enables RNA to leave the nucleus while DNA remains protected inside?

Accepted Answer

RNA is single-stranded and smaller, while DNA is double-stranded and larger

Question 5

A scientist discovers a mutation that prevents the addition of a 5' cap to pre-mRNA in a eukaryotic cell. What is the most likely consequence of this mutation?

Accepted Answer

The mRNA will be unable to exit the nucleus and may be degraded

Question 6

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

Accepted Answer

tRNA delivers specific amino acids to the ribosome by matching its anticodon to the mRNA codon

Question 7

In the context of gene expression, what is the function of a promoter region such as the TATAAA box?

Accepted Answer

It is the DNA sequence where RNA polymerase binds to initiate transcription

Question 8

A patient is diagnosed with a genetic disorder caused by the deletion of a single nucleotide in a gene. What is the most likely effect of this mutation on the resulting protein?

Accepted Answer

It will cause a frameshift, potentially altering every amino acid downstream

Question 9

Which of the following correctly matches the type of RNA with its primary function?

Accepted Answer

rRNA: combines with proteins to form ribosomes

Question 10

During translation, what is the significance of the start codon $$	ext{AUG}$$?

Accepted Answer

It signals the beginning of translation and codes for methionine

Question 11

Which of the following best explains why the genetic code is described as 'redundant'?

Accepted Answer

Multiple codons can specify the same amino acid

Question 12

A researcher is studying a gene that contains both exons and introns. What must happen to the pre-mRNA transcribed from this gene before it can be translated?

Accepted Answer

Introns must be removed and exons spliced together

Question 13

Which of the following scenarios best illustrates the role of epigenetic regulation in gene expression?

Accepted Answer

A gene is silenced due to methylation of its promoter region, without changing the DNA sequence

Question 14

Which of the following best describes the function of microRNA (miRNA) in gene regulation?

Accepted Answer

miRNA binds to mRNA and interferes with translation

Question 15

A cell is observed to have a Barr body. What does this indicate about the cell's gene expression?

Accepted Answer

The cell has inactivated one of its X chromosomes, reducing transcription from that chromosome

Question 16

During the elongation phase of translation, which event occurs repeatedly to build the polypeptide chain?

Accepted Answer

tRNA molecules bring amino acids to the ribosome, matching their anticodons to codons on the mRNA

Question 17

A geneticist is analyzing a segment of mRNA with the sequence $$5'	ext{-AUG-GGC-UAA-3'}. $$What is the sequence of amino acids produced from this mRNA during translation?

Accepted Answer

Methionine - Glycine

Question 18

Which of the following best explains why RNA is considered a 'disposable transcript' in the process of gene expression?

Accepted Answer

RNA is a temporary copy of DNA that can be degraded after use, protecting the original genetic information

Question 19

Which of the following is the correct sequence of events in eukaryotic gene expression, from DNA to functional protein?

Accepted Answer

Transcription $$\rightarrow$$ RNA processing $$\rightarrow$$ Translation

Gene Expression and Regulation: From DNA to Protein

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