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TLS Online TPP Program

#Question id: 12482

The Rb protein has been called the “master brake” of the cell cycle. How the Rb protein acts as a cell cycle brake?

#Unit 2. Cellular Organization
  1. Rb bound to E2F and function as transcriptional repressors because Rb recruits chromatin-modifying enzymes that promote deacetylation and methylation of specific histone lysines, causing chromatin to assume a condensed, transcriptionally inactive form.
  2. S phase CDKs and mitotic CDKs maintain Rb protein in the phosphorylated state throughout the S, G2, and early M phases.
  3. Rb bound to E2F and promotes ubiquitinylation of E2F and inhibits chromosomal segregation.
  4. Rb bound to E2F and promotes acetylation which prevents unloading of cohesins.
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TLS Online TPP Program

#Question id: 24330

#Unit 4. Cell Communication and Cell Signaling

Ions, low-MW precursors of cellular macromolecules, products of intermediary metabolism, & small intracellular signaling molecules can pass from cell to cell through_______?
TLS Online TPP Program

#Question id: 24331

#Unit 4. Cell Communication and Cell Signaling

Select the CORRECT combination by matching the junctions with their principal CAMs or adhesion receptors.

 Junctions Principal CAMs or Adhesion receptors
 1. Tight junctions a. Integrins
 2. Gap Junctions b. Occludin
 3. 3-D adhesions c. Connexin
 4. Plasmodesmata d. Undefined
TLS Online TPP Program

#Question id: 27111

#Unit 4. Cell Communication and Cell Signaling

Connexins and innexins play a very important role as a adhesion receptors for
TLS Online TPP Program

#Question id: 27112

#Unit 4. Cell Communication and Cell Signaling

Occludin and claudins are the principal CAMs of
TLS Online TPP Program

#Question id: 27113

#Unit 4. Cell Communication and Cell Signaling

Junction that shows attachment via adapters to other junctions is
TLS Online TPP Program

#Question id: 27114

#Unit 4. Cell Communication and Cell Signaling

A protein called Snail that suppresses the expression of _______is associated with the epithelial-to-mesenchymal transition (EMT).