Question 1

Molecular chaperones assist in the folding of newly synthesized mRNAs.

Accepted Answer

Molecular chaperones assist in the folding of newly synthesized proteins, not mRNAs.

Question 2

Reverse transcriptase catalyzes the synthesis of DNA from an RNA template.

Accepted Answer

Reverse transcriptase is an enzyme that synthesizes DNA from an RNA template, a process essential for the replication of retroviruses.

Question 3

A ribosome has one binding site for mRNA and two binding sites for tRNAs.

Accepted Answer

A ribosome has one binding site for mRNA and three binding sites for tRNAs, known as the A (aminoacyl), P (peptidyl), and E (exit) sites.

Question 4

RNA polymerase binds to the promoter sequence in RNA.

Accepted Answer

RNA polymerase binds to the promoter sequence in DNA to initiate the transcription of RNA, not to a sequence in RNA itself.

Question 5

How does the redundancy of the genetic code contribute to evolution?

Accepted Answer

The answer of How does the redundancy of the genetic...

Question 6

One function of snoRNAs is to process pre-rRNA molecules in the mitochondrion.

Accepted Answer

snoRNAs (small nucleolar RNAs) primarily function in the chemical modification and processing of pre-rRNA (precursor ribosomal RNA) within the nucleolus of the cell nucleus, not the mitochondrion.

Question 7

RNA interference is a process by which noncoding RNA molecules regulate gene expression.

Accepted Answer

RNA interference (RNAi) is a biological process in which RNA molecules inhibit gene expression or translation, by neutralizing targeted mRNA molecules. Noncoding RNAs, such as microRNAs and small interfering RNAs, play a key role in this gene silencing mechanism.

Question 8

Match between columns
                        Premises: large RNA molecules; regulates chromatin structure

Accepted Answer

The Answer of lncRNA and miRNA and siRNA and piRNA is...

Question 9

In eukaryotes, the initiator tRNA carries the amino acid leucine.

Accepted Answer

In eukaryotes, the initiator tRNA carries the amino acid methionine, not leucine.

Question 10

The poly-A tail is thought to facilitate the export of mRNA from the nucleus.

Accepted Answer

The poly-A tail, added to mRNA during processing, aids in the export of mRNA from the nucleus to the cytoplasm, where it can be translated into protein.

Question 11

The enzyme peptidyl transferase catalyzes peptide bond formation during the elongation stage of translation.

Accepted Answer

Peptidyl transferase is an enzyme integral to the ribosome's large subunit, responsible for catalyzing the formation of peptide bonds between amino acids during the elongation phase of protein synthesis (translation).

Question 12

snRNPs function to splice introns together.

Accepted Answer

snRNPs function to remove introns from pre-mRNA, not to splice them together; they are involved in splicing exons together.

Question 13

Signal-recognition particle RNA is involved in directing the ribosome-mRNA-polypeptide complex to the rough ER.

Accepted Answer

The signal-recognition particle (SRP) RNA is a component of the SRP complex, which plays a crucial role in targeting ribosome-bound nascent polypeptides to the rough endoplasmic reticulum (ER) for translocation into the ER lumen, a process essential for the proper sorting and processing of membrane and secretory proteins.

Question 14

A(n) nonsense mutation is a base-pair substitution that results in the replacement of one amino acid with another.

Accepted Answer

A nonsense mutation is a base-pair substitution that results in a premature stop codon, leading to the production of a truncated, and usually nonfunctional, protein.

Question 15

Eukaryotic mRNA has a significantly longer half life than its prokaryotic counterpart. How is this accomplished in eukaryotes? What processes tend to degrade mRNA molecules in both eukaryotes and prokaryotes, and why are these processes needed?

Accepted Answer

The answer of Eukaryotic mRNA has a significantly longer half...

Question 16

A(n) transposon is a DNA sequence that "jumps" into the middle of a gene.

Accepted Answer

Transposons, also known as "jumping genes," are DNA sequences that can change their position within the genome, sometimes inserting themselves into the middle of genes and potentially disrupting their function.

Question 17

In the process of transcription, incoming RNA nucleotides are in their triphosphates form.

Accepted Answer

During transcription, RNA polymerase catalyzes the addition of incoming ribonucleoside triphosphates (rNTPs) to the growing RNA strand, using them as substrates. The high-energy triphosphate group provides the energy needed for the polymerization reaction.

Question 18

Transcription and translation occur simultaneously in prokaryotes. Why can't this process take place in eukaryotes? What disadvantage results from such linking in prokaryotes?

Accepted Answer

The answer of Transcription and translation occur simultaneously in prokaryotes....

Question 19

A single nucleotide substitution within a gene is associated with type 1 diabetes and a decrease in insulin secretion. What type of mutation is this? What type of protein (ion channel, hormone, peptide/hormone channel, peptide/hormone pump) is affected?

Accepted Answer

The answer of A single nucleotide substitution within a gene...

Question 20

The 3' trailing sequences are located upstream of the stop codon.

Accepted Answer

The 3' trailing sequences are located downstream of the stop codon, as they are part of the mRNA sequence that extends from the stop codon to the poly(A) tail.

Quiz 13: Gene Expression