Chapter 15 Genetics Study Guide Questions

Which DNA sequence would also work in place ofthe following bi-directional enhancer? 5' GTTC 3'3' CAAG 5'

5' GAAC 3'3' CTTG 5'

Which of the following might complicate the interpretation of ChIP-Seq data?

Because histones can be moved around or ejected from the chromatin,DNA that is only sometimes wrapped around a histone might not be sequenced.

Which of the following is the most likely location of an insulator sequence?

Between two genes

Which one of the following directly interacts with the DNA as a transcriptional regulator?

CREB protein dimer

Histone acetyltransferases are directly involved in which of the following?

Chemical modification of histones

Which DNA sequence important for gene expression is usually contained within the NFR?

Core promoter

CpG islands are associated with which of the following?

DNA methylation

Genomic imprinting is a result of ___________.

DNA methylation

What would be the result of a mutation in Hsp90that prevented its binding to the glucocorticoid receptor?

Expression of the regulated genes would become constitutive.

Which of the following is a region in DNA that binds to a steroid receptor?

GRE

A mutation in which of the following would result in little or no effect on the expression of a gene regulated by a CRE?

Glucocorticoid receptor

For which of the following histones has variant forms not yet been identified?

H4

Which of the following is a major finding from the ENCODE project?

More than 80% of the human genome sequence is linked to a biological function.

In numerous studies that investigate gene expression, the mRNA levels of proteins are examined. If one is interested in the amount of protein being produced, is this the best approach to use?

No, directly determining the amount of protein produced would be best because many steps are involved in regulating protein levels.

What activates CREB?

Phosphorylation

Which of the following recognizes response elements, control elements, and regulatory elements?

Regulatory transcription factors

What general transcription factor is most often affected by regulatory transcription factors?

TFIID

In ChIP-Seq, the DNA fragments to be sequenced are around 150 bp in length. What does this size of DNA represent?

The amount of DNA wrapped around a nucleosome

A particular gene has a mutation in its NFR that causes it to bind abnormally tightly to histones. What effect would you expect this mutation has on the expression of this gene?

The expression of the gene would be abnormally low or absent.

What might happen if the insulator between two genes is missing?

Transcription factors influencing one gene's expression may abnormally influence a neighboring gene's expression.

If a DNA tempate is being transcribed in vitro what would be the effect on RNA production if an inhibitor of TFIID was added?

Transcripts being produced would continue but there would be no new initiation.

In the presence of abundant iron in the cell, the iron binds IRP. The complex is then released from IREs leading to __________.

an increase in ferritin mRNA translation and a decrease in transferrin receptor mRNA stability

A mutation in the iron response protein (IRP) that made it incapable of binding iron would result in __________.

constitutive transferrin receptor and no ability to stimulate ferritin expression

Researchers frequently wish to produce proteins in cells in a regulated fashion so that the effects of the protein can be studied under conditions then and when it is not present. Which of the strategies outlined below would be best suited for these types of studies?

Creating a piece of DNA where the gene for the protein of interest is under control of a glucocorticoid response element.

In apoptosis, a process of programmed cell death, the cell undergoes controlled degradation of cellular components including nuclear DNA. Researchers have noted that if the DNA is isolated from an apoptotic cell, it appears as distinct bands of multiples of approximately 145 bases in length. Why does this occur?

DNA that is wrapped around the histones is not being degraded.

A particular cell contains all of the standard histones but lacks several histone variants. Which of the following MAY be true of this cell?

The cell will express different sets of genes than other cells in the same organism.