Question 1

An upstream activator sequence (UAS)can function at variable distances and in either orientation.However,it differs from an enhancer in that it cannot function downstream of the transcription starting point.

Accepted Answer

An upstream activator sequence (UAS) can function at variable distances and in either orientation, but it cannot function downstream of the transcription starting point.

Question 2

Alternative RNA processing generates different mRNAs,which can direct the synthesis of different polypeptides.

Accepted Answer

Alternative RNA processing, such as alternative splicing or polyadenylation, can result in the production of different mRNAs with varying coding sequences, leading to the synthesis of different polypeptides.

Question 3

One of the earliest steps in the RNAi pathway involves the association of siRNA or miRNA molecules with an enzyme complex composed mainly of reverse transcriptase.

Accepted Answer

The statement is incorrect. The enzyme complex involved in the RNAi pathway is called RISC (RNA-induced silencing complex), composed mainly of proteins such as Argonaute.

Question 4

The term spliceopathy would be a reasonable term to signify a genetic condition caused by a defect in the regulation of RNA splicing.

Accepted Answer

The term spliceopathy accurately describes a genetic condition caused by a defect in RNA splicing regulation. Therefore, the statement is true.

Question 5

Alternative RNA processing can result in different mRNAs that start with different exons.

Accepted Answer

Alternative RNA processing, such as alternative splicing and alternative promoter usage, can result in different mRNA transcripts that start with different exons. Therefore, the answer is true.

Question 6

Transcription factors are proteins with at least two functional domains-one that binds to DNA and one that binds to RNA polymerase or to other transcription factors.

Accepted Answer

Transcription factors have at least two functional domains, one of which binds to DNA and another that binds to RNA polymerase or other transcription factors. This enables them to regulate gene expression by turning genes on or off.

Quiz 17: Regulation of Gene Expression in Eukaryotes