Question 1

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

Accepted Answer

DNA \rightarrow RNA \rightarrow Protein

Question 2

During transcription in eukaryotes, which strand of DNA is used as the template for mRNA synthesis?

Accepted Answer

The template strand

Question 3

A mutation changes the DNA sequence from TATAAT to TACGAT in the -10 region of a bacterial promoter. What is the most likely effect?

Accepted Answer

Transcription frequency will decrease

Question 4

Which of the following statements about codons is TRUE?

Accepted Answer

A codon is a sequence of three ribonucleotide bases that specifies an amino acid

Question 5

What is the role of the sigma factor in bacterial transcription?

Accepted Answer

It helps RNA polymerase recognize and bind to promoter sequences

Question 6

Which of the following is a key difference between transcription in prokaryotes and eukaryotes?

Accepted Answer

Prokaryotes can begin translation before transcription is complete

Question 7

A scientist isolates a mature eukaryotic mRNA and finds that it contains a 5' cap and a poly-A tail. What is the primary function of these modifications?

Accepted Answer

To protect the mRNA and aid in ribosome binding and export

Question 8

Which of the following sequences acts as a start codon in mRNA?

Accepted Answer

$$\mathrm{AUG}$$

Question 9

In bacteria, which mechanism leads to transcription termination by forming a hairpin secondary structure?

Accepted Answer

Intrinsic termination

Question 10

During translation, what is the function of tRNA?

Accepted Answer

It brings amino acids to the ribosome and matches codons via its anticodon

Question 11

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

Accepted Answer

Multiple codons can specify the same amino acid

Question 12

A mutation in the Shine-Dalgarno sequence of a bacterial mRNA would most likely affect which process?

Accepted Answer

Translation initiation

Question 13

Which of the following is TRUE regarding mRNA processing in eukaryotes?

Accepted Answer

Introns are removed and exons are joined by the spliceosome

Question 14

What is the correct order of events in gene expression from DNA to protein in eukaryotes?

Accepted Answer

Transcription in nucleus \rightarrow mRNA processing \rightarrow export to cytoplasm \rightarrow translation at ribosome

Question 15

Which of the following statements about RNA polymerase in prokaryotes is CORRECT?

Accepted Answer

It binds directly to promoter regions with the help of sigma factors

Question 16

A patient has a mutation that prevents the addition of a poly-A tail to mRNA. What is the most likely consequence?

Accepted Answer

The mRNA will be rapidly degraded and poorly exported from the nucleus

Question 17

Which of the following is NOT a function of ribosomal RNA (rRNA)?

Accepted Answer

Carrying amino acids to the ribosome

Question 18

In eukaryotic transcription, what is the role of transcription factors?

Accepted Answer

They help RNA polymerase bind to the promoter

Question 19

Which of the following best describes the process of translation elongation?

Accepted Answer

New tRNA enters the A site, peptide bond forms, and ribosome shifts to the next codon

Question 20

A researcher observes that a bacterial gene is only expressed during heat shock. Which sigma factor is most likely involved?

Accepted Answer

$$\$$sigma^{32}$$

Genetic Code, Transcription, and Translation: From DNA to Protein

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