Genetic Sequences, Transcription, and Translation

This is an MCQ-based quiz for GRE on Genetic Sequences, Transcription, and Translation.

This includes adenine (A), thymine (T), cytosine (C), and guanine (G), pre-initiation, initiation, promoter clearance, elongation, and termination.

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__________ are parts of __________ molecules that do not contain information about a protein"s primary structure.

Introns . . . pre-mRNA Introns . . . mRNA Exons . . . pre-mRNA Exons . . . mRNA

The primary transcript is much longer than the mRNA that will eventually be translated. This can be explained by which of the following?

The 5' cap has not yet been added to the transcript The poly-A tail is still on the primary transcript Exons have not yet been added to the transcript Introns have not yet been removed from the transcript

In most cases, introns are spliced out of mature messenger RNA (mRNA) and are not a part of the final translated protein product of a gene. Even though they are not included in the final protein, why are introns important?

None of these Introns can generate non coding RNAs that influence gene expression Introns allow for alternative splicing of exons to create multiple proteins from one gene sequence Introns are involved in some special regulatory functions like mRNA export and non-sense mediated decay All of these

In eukaryotes, which of the following is true about introns and exons?

The mature mRNA transcript only contains the introns because the exons have been spliced out. The primary RNA transcript contains both intronic and exonic regions. Intronic regions typically code for transcription factors. Exons are repeating sequences that are typically found at the distal ends of a gene. The mature mRNA transcript contains a mix of introns and exons.

In a eukaryotic cell, a molecule of pre-mRNA is found to have four exons and three introns. Which of the following are possible combinations of the exons, if the order in which they are written is the order in which they will be translated? I. Exon 1, Exon 2, Exon 3, Exon 4 II. Exon 1, Exon 3, Exon 4 III. Exon 4, Exon 1, Exon 2, Exon 3

II only I, II, and III I only I and II

Which of the following post-translation modifications cannot be classified as lipidation?

Addition of GPI-anchor Ubiquitination Prenylation Myristoylation Palmityolation

If a gene produces a pre-RNA that is 1200 basepairs long and has the following intron-exon structure: Exon 1 - 200 bp Intron 1 - 100 bp Exon 2 - 50 bp Intron 2 - 150 bp Exon 3 - 700 bp How many basepairs long would we expect the mRNA to be?

1000 basepairs 500 basepairs 950 basepairs 250 basepairs 1150 basepairs

Which of the following accurately describes the promoter?

The binding site for DNA polymerase on DNA The attachment point for a ribosome before translation The protein that attaches to DNA in order to create mRNA A sequence of DNA used to signal the beginning point of transcription

Which conditions would result in the largest levels of lac operon transcription?

Low lactose and high glucose Low lactose and low glucose High lactose and high glucose High lactose and low glucose

The lac operon is typically found in prokaryotes in order to utilize lactose in the event that glucose is absent. How does the presence of lactose affect the lac operon?

It binds to the promoter, signaling the polymerase to attach It binds to the lac repressor, causing it to detach from the operator It stimulates the transcription of the lac repressor gene It attaches to the operator, blocking polymerase from attaching
Quiz/Test Summary
Title: Genetic Sequences, Transcription, and Translation
Questions: 10
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