Practice Questions

TLS Online TPP Program

#Question id: 13159

How signaling is involved in ensuring that yeast cells fuse only with cells of the opposite mating type?

#Unit 4. Cell Communication and Cell Signaling

The two cells of opposite mating type (a and alpha) each secrete a certain signaling molecule, which can only be bound by receptors carried on cells of the opposite mating type. Thus, the a mating factor cannot bind to another a cell and cause it to grow toward the first a cell. Only an alpha cell can “receive” the signaling molecule and respond by directed growth.
The two cells of opposite mating type (a and alpha) each secrete a certain signaling molecule, which can only be bound by receptors carried on cells of the same mating type. Thus, the a mating factor can bind to another a cell and cause it to grow toward the first a cell.
The two cells of opposite mating type (a and alpha) each proteins attached to the plasma membrane of one cell can interact directly with cell-surface receptors on adjacent cells. Thus, the a mating factor can directly bind to another a cell and cause it to grow.
The two cells of opposite mating type (a and alpha) each respond to substances that they themselves release.

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TLS Online TPP Program

#Question id: 2829

#Unit 2. Cellular Organization

Scaffold-associated regions

a. are the chromosome attachment points for the mitotic spindle.

b. can insulate transcription units from each other.

c. are the points at which DNA interacts with histone proteins.

d. are found between transcription units.

TLS Online TPP Program

#Question id: 2830

#Unit 2. Cellular Organization

The NtrC protein from E. coli

a. is a σ54 RNA polymerase.

b. stimulates transcription of the glnA gene.

c. is activated by a protein kinase called NtrB.

d. binds both to an enhancer site upstream of the glnA gene and to RNA polymerase.

e. has ATPase activity.

TLS Online TPP Program

#Question id: 2831

#Unit 2. Cellular Organization

Specific DNA control elements in promoters can

a. interact with general transcription factors.

b. interact with repressor proteins.

c. interact with activator proteins.

d. remain unavailable because of condensed chromatin.

TLS Online TPP Program

#Question id: 2832

#Unit 2. Cellular Organization

Reporter genes are used to

a. express enzymes that are not easily assayed in cell extracts.

b. express enzymes that are easily assayed in cell extracts.

c. characterize DNA control elements.

d. characterize reporter plasmids.

TLS Online TPP Program

#Question id: 2835

#Unit 2. Cellular Organization

An enhancer

a. can be located upstream of a promoter.

b. can be located downstream of a promoter.

c. can be located a variable distance from the promoter.

d. is always located within 1 kb of the promoter.

e. can be cell-type-specific.

TLS Online TPP Program

#Question id: 2836

#Unit 2. Cellular Organization

The fact that a specific protein leaves a “footprint” on a DNA molecule is indicative of

a. a lack of interaction between the specific protein and DNA.

b. protection from DNAse by the specific protein.

c. binding of the specific protein to all types of DNA.

d. binding of the specific protein to a specific sequence of DNA.