Q: A scientist uses RT-PCR to quantify mRNA levels of a gene in treated and untreated cells. The amount of amplified product is proportional to the amount of mRNA present. Which equation best represents this relationship?

$$\text{Amplified Product} = \text{Amount of mRNA} \times \text{PCR Efficiency}$$

Question 1

Which of the following best describes the purpose of 5' capping in eukaryotic mRNA processing?

Accepted Answer

It protects the mRNA from degradation and is required for translation initiation.

Question 2

A researcher wants to measure the expression levels of all genes in a cancer tissue sample. Which technique should they use?

Accepted Answer

RNA-Seq

Question 3

During mRNA splicing, which snRNP is responsible for recognizing the 5' splice site?

Accepted Answer

U1

Question 4

Which of the following is NOT a direct result of alternative splicing?

Accepted Answer

Variation in the 3' end of mRNA due to alternative polyadenylation

Question 5

A scientist uses RT-PCR to quantify mRNA levels of a gene in treated and untreated cells. The amount of amplified product is proportional to the amount of mRNA present. Which equation best represents this relationship?

Accepted Answer

$$	ext{Amplified Product} = 	ext{Amount of mRNA} 	imes 	ext{PCR Efficiency}$$

Question 6

Which element is essential for the formation of the lariat structure during pre-mRNA splicing?

Accepted Answer

Branch point adenosine

Question 7

In mRNA in situ hybridization, what is the main function of the labelled probe?

Accepted Answer

To hybridize to the complementary mRNA and reveal its spatial location

Question 8

Which of the following statements about polyadenylation is TRUE?

Accepted Answer

Polyadenylation increases mRNA stability and is necessary for translation.

Question 9

A gene encodes both calcitonin and CGRP hormones through alternative splicing. What does this illustrate?

Accepted Answer

A single gene can produce multiple proteins by using different exons.

Question 10

Which consensus sequence is typically found at the 5' splice site of an intron?

Accepted Answer

$$	ext{GU}$$

Question 11

What is the main difference between RT-PCR and RNA-Seq in gene expression analysis?

Accepted Answer

RNA-Seq is a high-throughput method that quantifies the transcriptome, while RT-PCR is low-throughput and targets specific genes.

Question 12

Which step occurs LAST during spliceosome-mediated splicing?

Accepted Answer

Cleavage at the 3' splice site and joining of exons.

Question 13

A mutation disrupts the branch point sequence in an intron. What is the most likely consequence?

Accepted Answer

Impaired formation of the lariat and defective splicing.

Question 14

Which of the following is a direct outcome of alternative promoters in gene expression?

Accepted Answer

Variation in the 5' end of the transcript

Question 15

If a pre-mRNA lacks a polyadenylation signal, what is the most likely result?

Accepted Answer

The mRNA will be unstable and rapidly degraded.

Question 16

Which formula best represents the calculation of gene expression level using RNA-Seq data?

Accepted Answer

$$	ext{Expression Level} = \frac{	ext{Number of Reads Aligned to Gene}}{	ext{Total Number of Reads}}$$

Question 17

Which of the following is TRUE regarding the spliceosome?

Accepted Answer

It is composed of snRNPs that recognize splice sites via base-pairing.

Question 18

A patient’s cells show reduced stability of mRNAs. Which molecular feature is most likely shortened in these mRNAs?

Accepted Answer

Poly-A tail

Question 19

Which of the following steps is NOT part of eukaryotic mRNA processing?

Accepted Answer

Removal of exons by the spliceosome

Question 20

A gene produces multiple mRNA isoforms due to the use of alternative polyadenylation sites. What is the most direct effect of this mechanism?

Accepted Answer

Variation in the 3' untranslated region (UTR) of the mRNA

Eukaryotic mRNA Processing and Methods for Measuring Gene Expression

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