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

$$\text{DNA} \to \text{RNA} \to \text{Protein}$$

Question 1

Which enzyme is primarily responsible for synthesizing RNA during transcription, and in which direction does it add nucleotides to the growing RNA strand?

Accepted Answer

RNA polymerase; 5' to 3' direction

Question 2

During translation, what is the role of the anticodon found on tRNA molecules?

Accepted Answer

It base pairs with the complementary codon on mRNA to ensure the correct amino acid is added.

Question 3

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

Accepted Answer

$$	ext{DNA} 	o 	ext{RNA} 	o 	ext{Protein}$$

Question 4

A mutation changes the DNA sequence from $$	ext{TAC} to$$ $$	ext{TAG}. $$What is the effect on translation?

Accepted Answer

Translation will terminate prematurely due to a stop codon.

Question 5

Which of the following codons serves as the start codon for translation in most organisms?

Accepted Answer

$$	ext{AUG}$$

Question 6

What is the function of ribosomes during protein synthesis?

Accepted Answer

They catalyze the reaction that joins amino acids to form a polypeptide chain.

Question 7

Which statement best explains the degeneracy of the genetic code?

Accepted Answer

Multiple codons can code for the same amino acid.

Question 8

If a segment of DNA has the sequence $$5'	ext{-ATGCGT-}3'$$, what is the sequence of the complementary mRNA produced during transcription?

Accepted Answer

$$5'	ext{-UACGCA-}3'$$

Question 9

Which of the following best describes the 'wobble hypothesis' in translation?

Accepted Answer

The third base of the codon can form non-standard base pairs, allowing some tRNAs to recognize multiple codons.

Question 10

Which process occurs in the nucleus and involves copying a gene's DNA sequence into an RNA molecule?

Accepted Answer

Transcription

Question 11

What is the significance of the A, P, and E sites on the ribosome during translation?

Accepted Answer

They are sites where tRNAs bind and move through as amino acids are added to the growing polypeptide.

Question 12

Which of the following is a stop codon in the genetic code?

Accepted Answer

$$	ext{UAA}$$

Question 13

A scientist mutates the gene for a tRNA synthetase so that it attaches the wrong amino acid to a tRNA. What is the most likely result?

Accepted Answer

The wrong amino acid will be incorporated into the protein at the codon recognized by that tRNA.

Question 14

Which of the following best describes the relationship between codons and amino acids?

Accepted Answer

Each codon is a sequence of three nucleotides that specifies a particular amino acid.

Question 15

Which of the following statements about translation is correct?

Accepted Answer

Translation requires ribosomes, tRNAs, and mRNA.

Question 16

If the mRNA sequence is $$5'	ext{-AUGGCCUAA-}3'$$, what is the sequence of amino acids produced (using the standard genetic code)?

Accepted Answer

Methionine - Alanine - Stop

Question 17

Which of the following is a real-world example of the importance of the universality of the genetic code?

Accepted Answer

Human genes can be expressed in bacteria to produce insulin for diabetes treatment.

Question 18

What would happen if a mutation changed a stop codon (e.g., UGA) to a sense codon (e.g., UGG)?

Accepted Answer

Translation would continue, adding more amino acids until another stop codon is encountered.

Question 19

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

Accepted Answer

Some amino acids are coded by more than one codon.

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