Practice test

Which of the following pieces of DNA would you expect to be most susceptible to DNase-I digestion?

"naked" dna not bound to histones

In RNA editing, the guide RNA:

Can control the insertion or deletion of uracils.

Which of these would be the best evidence for a functional role of RNA interference in resistance to viral infection?

Cells resistant to one double stranded RNA virus tend to be resistant to all double stranded RNA viruses.

RNA editing:

Occurs in widely varied species.

The stability of a particular mRNA can be enhanced by

Presence of short bits of antisense RNa.

Extracellular signaling molecules:

Usually bind plasma membrane receptors which then pass along the signal

DNA sites bound by regulatory transcription factors...

are cis citing factors

Control of the function of receptor tyrosine kinases primarily occurs at what level?

posttranslational modification

Changes in function of which of the following proteins by posttranslational modification (such as phosphorylation or acetylation) would be likely to, in turn, affect the expression of specific genes?

IRP

in order for CREB (cAMP response element-binding protein) to activate transcription..

It must be phosphorylated.

In comparing effects of regulatory transcription factors that affect TFIID and those that affect mediator:

Mediator allows binding of RNA polymerase but transcription can be prevented by transcription factors binding to silencers

The best explanation for interference of DNA methylation with transcription factor binding is:

Methylation of the CpG island modifies the shape of the response element to which the transcription factor normally binds.

homodimer

is a pair of identical proteins

Gene AMPLIFICATION is different from other alterations in DNA structure because:

ther is addition of dna

Housekeeping genes...

Are constitutively expressed.

Control of alternative splicing involves:

Repressors, which cause exon skipping.Enhancers, which increase recognition of weak splice sites. Splicing factors, which modulate spliceosome function.

gene regulation in eukaryotes may be influenced by:

enviornmental conditions, developmental stage, tissue or cell type

true/false? A CpG island consists of about 2000 copies of the CG dinucleotide.

false

true/false? Transcription factors, if present, will always bind their appropriate response elements.

false

Two different proteins produced by alternative splicing are most likely to:

have similar functions under diff forms of regulation

true/ false? DNA in an open configuration is more likely to be transcribed than DNA in a closed configuration

true

true/ false? transcription factor is a protein that affects the ability of RNA polymerase to transcribe a gene.

true

true/false? Methylation of DNA is a heritable trait.

true

true/false? Response elements may be located within the gene itself.

true

true/false? The length of the poly-A tail has a dramatic effect on RNA stability.

true

true/false? a single RNA molecule can encode several different proteins.

true