Question 1

Which of the following best describes the Central Dogma of Molecular Biology?

Accepted Answer

DNA is transcribed into RNA, which is then translated into proteins.

Question 2

During transcription, which DNA strand does RNA polymerase use as a template?

Accepted Answer

The template strand, which is read in the 3' to 5' direction.

Question 3

A DNA sequence is 5'-ATG GCT TAA-3' (coding strand). What is the corresponding mRNA sequence after transcription?

Accepted Answer

$$5'	ext{AUG GCU UAA}3'$$

Question 4

Which of the following modifications occur to eukaryotic pre-mRNA before it becomes mature mRNA?

Accepted Answer

Addition of a 5' cap and a poly-A tail, and removal of introns.

Question 5

Why is the genetic code described as 'redundant'?

Accepted Answer

Multiple codons can code for the same amino acid.

Question 6

A mutation changes a codon from UAU (tyrosine) to UAA (stop). What type of mutation is this?

Accepted Answer

Nonsense mutation

Question 7

Which of the following best explains why we need a new flu vaccine every year?

Accepted Answer

The influenza virus mutates frequently, changing the proteins targeted by the immune system.

Question 8

During translation, what is the function of tRNA?

Accepted Answer

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

Question 9

Given the following DNA template strand: 3'-TAC GGA TCC-5', what is the sequence of the mRNA produced?

Accepted Answer

$$5'	ext{AUG CCU AGG}3'$$

Question 10

Which of the following is a key difference between DNA and RNA?

Accepted Answer

RNA contains uracil instead of thymine.

Question 11

A gene contains the following sequence: Exon 1 - Intron - Exon 2. After RNA processing, what will the mature mRNA contain?

Accepted Answer

Exon 1 and Exon 2 joined together, with the intron removed.

Question 12

Which of the following best describes the direction in which RNA polymerase synthesizes mRNA?

Accepted Answer

5' to 3' direction

Question 13

A single base insertion occurs in the coding region of a gene. What is the most likely result?

Accepted Answer

A frameshift mutation, which alters the reading frame of the gene.

Question 14

Which of the following is NOT a function of the 5' cap added to eukaryotic mRNA?

Accepted Answer

It signals the start of DNA replication.

Question 15

In the context of the Central Dogma, what is the role of ribosomes?

Accepted Answer

They facilitate the translation of mRNA into a polypeptide chain.

Question 16

A watermelon from ancient Egypt is depicted as small and pale with white flesh, while modern watermelons are large and red. What biological process best explains this change?

Accepted Answer

Selective breeding (artificial selection) for desirable traits over generations.

Question 17

Which of the following best explains why the influenza virus can evade immunity from previous infections or vaccinations?

Accepted Answer

Frequent mutations in viral genes coding for surface proteins.

Question 18

A DNA template strand has the sequence 3'-TAC GTT ACC-5'. What is the amino acid sequence produced after transcription and translation? (Use the genetic code: AUG = Met, GUU = Val, ACC = Thr)

Accepted Answer

Met-Val-Thr

Question 19

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

Accepted Answer

Exons are expressed regions that remain in the mature mRNA, while introns are removed during RNA processing.

Transcription and Translation: From DNA to Protein

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