Question

9. Analyze the diagram below of a nuclear response for gene expression:

Receptor protein Phosphorylation DNA Transcription factor mRNA

Which of the following is this cell using to control all of the other events to regulate gene expression?
  
a. phosphate bonded to a transcription factor

b. phosphorylation cascade with multiple steps

c. specific hormone that initiates a response

d. transcription housed outside of the nucleus

10. Below is a model of a signal transduction pathway that results in the transcribing of mRNA:

Referencing the model, what determines if the cell should stop transcribing mRNA?
  
a. concentration of mRNA in the nucleus

b. levels of phosphates released by the cascade in the cytoplasm

c. passage of phosphates through the plasma membrane

d. presence of hormones outside of the cell

11. Look at the model below representing a signal transduction in a cell:

Which of the following is NOT true regarding this model of transduction?
  
a. Bonded signal molecules activate the cell permanently.

b. If the signal molecule isn't bonded to the surface protein, the ions cannot enter the cell

c. Internal ions will stimulate some type of cellular response.

d. Signal transductions are a protection mechanism that helps increase cellular efficiency.

Answer 1

9.b) phosphorylation cascade with multiple steps

as the phosphoryalation cascade is controling the phosphorylation of the trnascription factor thereby regulating gene expression.

10. d) presence of hormones outside of the cell

when hormone is present outside the cell, it will activates a phosphorylation cascade and which will ultimately control the phosphoryltion status of the transciption factor. As a result mRNA will be produced. On the other hand when the hormone is absent, there will be no signal from outside the cell, as a result phosphorylation cascade will remain inactive and there will be no phosphorylation of the transcription factor resulting in no mRNA production.

11. d) Signal transductions are a protection mechanism that helps increase cellular efficiency.

signal transduction is required to communicate between cells as well as to maintain interaction with the outside environement where the cell is.