Genetics 17

Front 1

This pre-mRNA contains three exons, two introns, and two alternative splice sites. How many unique proteins could alternative splicing generate?

Back 1

Two

Front 2

Transcriptional activator proteins bind to sequences in the _____________ promoter region and affect the rate at which transcription is initiated.

Back 2

regulatory

Front 3

CpG islands are regions of DNA with heavy cytosine

Back 3

methylation.

Front 4

Regions called ________ hypersensitive sites frequently develop approximately 1000 nucleotides upstream of the start site of transcription that indicates "active" sites of chromatin structure.

Back 4

DNase I

Front 5

Which of the following explanations concerning the reason as to why eukaryotic gene regulation being less well understood than bacterial gene regulation is INCORRECT?

Back 5

Scientists have not spent the same amount of time studying eukaryotes compared to prokaryotes.

Front 6

This protein is not produced in male Drosophila; in females, it regulates the splicing of sex determination genes.

Back 6

Sex-lethal (Sxl)

Front 7

The alternative splicing of the T-antigen gene of simian virus 40 (SV40) is regulated by the presence of splicing factor 2 (SF2), which is a(n) _________ protein that contains two domains, an RNA-binding region and another domain with alternating serine and arginine amino acids.

Back 7

SR

Front 8

Some eukaryotic regulatory proteins can inhibit transcription as repressor. Which of the following regions do repressors bind?

Back 8

Silencer

Front 9

Determine whether the following statement is true or false: Heavily methylated DNA is associated with the repression of transcription.

Back 9

True

Front 10

True or false? The histone code refers to the direct modification of DNA nucleotide to encode information that affects how genes are expressed.

Back 10

False

Front 11

The DNA sequences that block or negatively regulate the effect of enhancers in a position-dependent manner is referred to as

Back 11

insulators.

Front 12

Which of the following is not part of the basal transcription apparatus?

Back 12

Ribonucleases

Front 13

Which of the following is a component of chromatin remodeling complexes, which bind directly to particular sites on DNA and reposition the nucleosomes, altering chromatin structure without modifying the chemical structure of the histones directly?

Back 13

SWI

Front 14

True or false? The histone code refers to the direct modification of DNA nucleotide to encode information that affects how genes are expressed.

Back 14

False

Front 15

Choose the correct description of function for the specific domain of histone proteins.

Back 15

The globular domain associates with other histone proteins.

Front 16

Which of the following statements about transcriptional activator proteins is INCORRECT?

Back 16

They bind to the sugar phosphate backbone as they do not require specific consensus base sequence to bind to the DNA.

Front 17

In yeast cells, the absence of galactose causes GAL80 to bind to GAL4 and prevent transcription activation of galactose metabolizing genes. When galactose is present, it binds to GAL3, causing it to interact with GAL80 and release GAL4 to activate transcription of genes necessary for galactose metabolism. Which of the following hypotheses would be correct to explain the cause of a yeast cell that is unable to properly metabolize galactose?

Back 17

A mutation in the GAL80 protein results in an inability to undergo conformational changes resulting in constitutive interaction with GAL4.

Front 18

You have isolated a protein that you hypothesize to be a transcriptional activator. What is one characteristic of the protein that would support your hypothesis?

Back 18

The protein contains helix-turn-helix and zinc-finger motifs.

Front 19

Pieces of pre-mRNA that are removed by splicing proteins prior to translation are called

Back 19

introns.

Front 20

An enzyme called _____________ cleaves and processes double-stranded RNA to produce siRNAs or miRNAs.

Back 20

Dicer

Front 21

Which of the following is a component of chromatin remodeling complexes, which bind directly to particular sites on DNA and reposition the nucleosomes, altering chromatin structure without modifying the chemical structure of the histones directly?

Back 21

SWI

Front 22

Determine whether the following statement is true or false: Heavily methylated DNA is associated with the repression of transcription.

Back 22

True

Front 23

What is one mechanism by which chromatin-remodeling complexes reposition nucleosomes?

Back 23

They change the conformation of DNA and/or nucleosomes so that DNA that is bound to nucleosomes assumes a more exposed conformation.

Front 24

Regions called ________ hypersensitive sites frequently develop approximately 1000 nucleotides upstream of the start site of transcription that indicates "active" sites of chromatin structure.

Back 24

DNase I

Front 25

CpG islands are regions of DNA with heavy cytosine

Back 25

methylation.

Front 26

True or False? RNA interference is a mechanism that is only present in animal cells.

Back 26

False

Front 27

Which characteristic of gene regulation is shared between prokaryotes and eukaryotes?

Back 27

DNA binding proteins influence the ability of RNA polymerase to initiate transcription.

Front 28

True or false? The histone code refers to the direct modification of DNA nucleotide to encode information that affects how genes are expressed.

Back 28

False

Front 29

True or False? In both prokaryotes and eukaryotes, pre-mRNAs are processed before being translated.

Back 29

False

Front 30

Which part of eukaryotic mRNA would contain AU-rich elements, which affect stability by being bound to microRNAs?

Back 30

3′ UTR

Front 31

The location of the pre-mRNA that small nuclear ribonucleoproteins (snRNPs) bind to in order to perform splicing is the

Back 31

5′ splice site.

Front 32

Which of the following effects on transcription would histone deacetylation generally have?

Back 32

Repression of transcription

Front 33

Acetylation of the Arabidopsis flowering locus C (FLC) plays an important role in suppressing flowering until after an extended period of coldness. The active FLC encodes a protein that represses the activity of other genes that affect flowering. The activity of FLC is controlled by the flowering locus D (FLD) that stimulates flowering by repressing the action of FLC. FLD is a deacetylase enzyme that removes acetyl groups around the chromatin surrounding FLC. What would the predicted result be if FLD is present but has lost its deacetylase activity?

Back 33

The FLC locus would remain acetylated and active, resulting in continuous suppression of flowering even after exposure to extended periods of coldness.

Front 34

Gene X is controlled by the heat-shock response element, whose sequence is CNNGAANNTCCNNG, and the serum response element, whose sequence is CCATATTAGG. Gene X transcribes cell surface receptors that bind to serum. Which of the following would NOT be the predicted outcome of a cell undergoing thermal stress such as extreme heat?

Back 34

Decreased mRNA production for gene X

Front 35

A scientist wishes to investigate if a region of DNA within a pancreas cell is being actively transcribed in response to insulin. What would she look for as evidence of active regions of DNA transcription?

Back 35

The ability of DNase I to cleave specific sites within the DNA

Front 36

Insulin stimulates the initiation of rapid overall protein synthesis by increasing the availability of initiation factors that typically exist in inactive forms. Which of the following experiments would help to determine if a specific initiation factor X is dependent on insulin-dependent protein synthesis?

Back 36

Tyrosine (Y) to phenylalanine (F) mutations to inhibit phosphorylation of initiation factor X

Front 37

A patient exhibits a disease resulting from a lack of a protein that is transcribed by gene X. The protein encoded by gene X cannot be detected in the patient's cells. Furthermore, the mRNA of gene X is absent as well. After genetic testing, it has been determined that gene X in this patient contains an abnormally large amount of cytosine- and guanine-rich repeats near the transcription start site of the DNA. Which of the following hypotheses could be generated from this finding?

Back 37

The chromatin of gene X is more heavily deacetylated compared to gene A from normal healthy individuals.

Front 38

Malaria is one of the most pervasive and destructive of all infectious diseases transmitted by mosquitos. About 300 million people worldwide are infected by malaria, which result in upward of a million deaths every year. The causative agents of malaria are protozoan parasites of the genus Plasmodium. The surface antigen is encoded by the var gene family, which consists of about 60 genes whose DNA sequences vary slightly. Expression of the type of var protein is known to change continuously, which allows parasites to evade the immune system. The var genes are located near the telomeres that are typically in heterochromatin state. The studies from 2006 revealed that the var genes are expressed when chromatin structure is disrupted via chemical changes in the histone proteins. Which of the following may serve as a plausible explanation that links var gene expression to chromatin changes?

Back 38

The H3K4me3 type modification on histone H3

Front 39

A transcriptional activator protein GAL4 and its inhibitor GAL 80 play important roles in the inducible regulation of galactose metabolism in yeast. Which of the following statements incorrectly describe the action of GAL4 and GAL80 in response to galactose?

Back 39

GAL80 contains several zinc fingers that allow its binding to UASG.

Front 40

Which of the following is NOT a mechanism of siRNA and miRNA gene regulation?

Back 40

Inhibition of pre-mRNA export from the nucleus

Front 41

True or False? All siRNA and miRNA degradation of mRNA requires the enzyme Dicer.

Back 41

False

Front 42

Which of the following is NOT a mechanism by which MOST repressors can inhibit eukaryotic transcription?

Back 42

Repressors directly block RNA polymerase.

Front 43

Which of the following statements about transcriptional repressors is correct?

Back 43

The repressors may compete with activators for the same DNA binding site.

Front 44

Which of the following statements concerning chromatin remodeling is correct?

Back 44

Chromatin remodeling complexes require energy to restructure nucleosomes, which may allow exposing certain regions of the DNA to the action of other regulatory proteins.

Front 45

Which of the following effects on transcription would histone deacetylation generally have?

Back 45

Repression of transcription

Front 46

True or False? RNA interference is a mechanism that is only present in animal cells.

Back 46

False

Front 47

Pieces of pre-mRNA that are removed by splicing proteins prior to translation are called

Back 47

introns.

Front 48

Genes that are coordinately expressed in eukaryotic cells are able to respond to the same stimulus due to short common regulatory sequences built into their promoters or enhancers called

Back 48

response elements.