Organisation and Control of Eukaryotic Genome 1 (MJC)

Which of the following mechanisms will result in an increased rate of gene expression of a protein?

1) An increase in the enzymatic activity of enzymes that degrade mRNA.
2) An increase in the activity of ribosomal translational initiation factors.
3) A decrease in the activity of ribosomal translational initiation factors.
4) An increase in the activity of repressors responsible for the expression of the gene.

Match the following regions of eukaryotic genome with their respective functions.
Region of genome Function
1) Silencer Binding site for activators
2) Telomere Binding site for transcription factors
3) Enhancers Binding site for repressors
4) Promoter Binding site for transcription factors

Transcription in eukaryotes may involve the use of an enhancer. What describes the role of an enhancer?

1) It is a gene that increases the production of an activator protein.
2) It is a promoter that increases the activity of RNA polymerase.
3) It is a protein that activates a specific promoter.
4) It serves as a binding site for an activator protein.

The amount of protein which is translated form a given mRNA strand depends partly on the

1) degree of DNA methylation
2) rate of mRNA degradation
3) presence of activator proteins
4) number of introns present in the mRNA

Which of the following is not a component of the transcription initiation complex?

1) TATA-binding protein
2) RNA
3) Activator
4) RNA polymerase

A region of eukaryotic DNA consists of over thirty repetitions of the same sequence of 12 bases. Where is this repetitive region least likely to be found?

1) an exon
2) a transposon
3) satellite DNA
4) an intron

Which statement is NOT true about the function of the poly(A) tail at the 3' end of a mRNA strand?

1) It prevents the degradation of the mRNA strand.
2) It acts as a binding site for RNA polyerase II to bind to to initiate transcription.
3) It serves as a part of a siganl to attach to the ribosomes.
4) It facilitates the exit of the mRNA strand out of the nucleus.

Telomeres are found on the ends of eukaryotic genome as a solution for the end-replication problem. Which of the following is NOT a function of telomeres?

1) It protects genes from being eroded and hence prevents DNA from shortening.
2) It prevents the fusion between the exposed ends of chromosomes and hence limits the chances of mutation.
3) It prevents unintentional cell death.
4) It enhances cellular aging and results in autolysis of the cell, thus reducing the chances of uncontrolled cellular divison.

Which of the following is NOT part of the post-transcriptional regulation in the eukaryotic genome?

1) Addition of a 5'cap and a poly(A) tail to the 3' end of the mRNA.
2) Alternative RNA splicing where introns as well as some exons are spliced out of the mRNA.
3) Enzymatic shortening of the poly(A) tail which triggers the degradation of the mRNA.
4) None of the above.

Telomeres are non-coding DNA sequences found at the ends of eukaryotic chromosomes which are catalysed by the enzyme telomerase.
Which of the following is a feature of human telomerase?

1) It is a single DNA molecule that provides an AAUCCC template to guide the insertion of the telomere.
2) It synthesizes RNA using a RNA template.
3) It is a ribonucleoprotein.

What describes common features of the telomere and the centromere?

1)Both areas have proteins associated with them.
2) Both are made up of DNA with a high incidence of cytosine and guanine.
3) Both DNA sequences are conserved throughout the life of the organism.
4) During interphase DNA replication takes place simultaneously in both regions.

In eukaryotes, transcription is generally associated with

1) Euchromatin and DNA methylation
2) Euchromatin and histone acetylation
3) Heterochromatin and histone methylation
4) Heterochromatin and histone acetylation

An example of post-translation processing would involve

1) cleaving of polypeptides to give the functional protein
2) Ubiquitination of proteins
3) Glycosylation of proteins
4) All of the above

Which of the following is NOT an example of a distal control element?

1) Enhancers
2) Silencers
3) Promoter-proximal element

The addition of an acetyl group to histones is an example of

1) chromatin modification
2) transcriptional processing
3) post transcriptional processing
4) post translational processing