Question 1

Which of the following statements best describes the flow of genetic information in most cells?

Accepted Answer

Genetic information flows from DNA to RNA to proteins.

Question 2

During transcription, which of the following base pairings occurs between DNA and RNA?

Accepted Answer

U pairs with A, G pairs with C.

Question 3

Which enzyme is required for reverse transcription, allowing RNA to be used as a template to build DNA?

Accepted Answer

Reverse transcriptase

Question 4

In eukaryotic cells, what is the primary function of the spliceosome during mRNA processing?

Accepted Answer

It removes introns and joins exons together.

Question 5

Which of the following best explains why the genetic code is considered redundant?

Accepted Answer

Multiple codons can code for the same amino acid.

Question 6

A mutation changes the codon UAU (tyrosine) to UAA in an mRNA sequence. What type of mutation has occurred?

Accepted Answer

Nonsense mutation

Question 7

Which of the following is TRUE regarding translation in prokaryotes compared to eukaryotes?

Accepted Answer

Translation in prokaryotes can begin before transcription is complete.

Question 8

Which of the following RNA types contains an anticodon loop and carries amino acids to the ribosome?

Accepted Answer

Transfer RNA (tRNA)

Question 9

If a mutation in a gene does NOT change the amino acid sequence of the resulting protein, what type of mutation is this?

Accepted Answer

Silent mutation

Question 10

How many unique codons are possible in the genetic code, given that there are 4 nucleotides and each codon consists of 3 nucleotides?

Accepted Answer

$$4^3 = 64$

Question 11

Which of the following is a consequence of a frameshift mutation?

Accepted Answer

The reading frame of the mRNA is altered, potentially changing all downstream amino acids.

Question 12

What is the role of ribosomal RNA (rRNA) in protein synthesis?

Accepted Answer

It folds into 3D structures and combines with proteins to form ribosomes.

Question 13

Which of the following is NOT a step in translation?

Accepted Answer

Replication

Question 14

A scientist observes that a single mRNA molecule in a prokaryote encodes several different proteins. What is the term for this type of mRNA?

Accepted Answer

Polycistronic

Question 15

Which of the following best describes the advantage of alternative mRNA splicing in eukaryotes?

Accepted Answer

It enables the production of multiple protein variants from a single gene.

Question 16

Which of the following codons is typically used as a start signal for translation?

Accepted Answer

AUG

Question 17

If E. coli adds 20 amino acids per second during translation and misreads one codon in every 10,000, what is the error rate per amino acid added?

Accepted Answer

$$\frac{1}{10,000}$$

Question 18

Which of the following is a function of post-translational modification?

Accepted Answer

It adds organic or inorganic groups to proteins, affecting their function.

Question 19

A mutation in the CFTR gene leads to cystic fibrosis. Which class of mutation is most likely to result in a nonfunctional chloride channel protein?

Accepted Answer

Nonsense mutation

Question 20

Which of the following best describes the role of exons in eukaryotic mRNA?

Accepted Answer

Exons are segments of mRNA that are decoded to build proteins.

Protein Synthesis: Transcription, Translation, and the Genetic Code CHAPTER. 5B

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