In many endotherms, shivering occurs in cold conditions whereby the body undergoes rapid muscle contractions without any locomotion.

When the body temperature falls, brown fat cells increase their metabolic rate, and hence heat production.

TLS Online TPP Program

#Id: 10418

#Unit 4. Cell Communication and Cell Signaling

Metastasis

cancer cells have acquired the ability to penetrate basement membranes using a cell protrusion called an invadopodium

TLS Online TPP Program

#Id: 10419

#Unit 4. Cell Communication and Cell Signaling

Epithelial-to-mesenchymal transition (EMT) 

play a crucial role in metastasis

TLS Online TPP Program

#Id: 10420

#Unit 4. Cell Communication and Cell Signaling

Heart of the EMT are two transcription factors, 

Snail and Twist

TLS Online TPP Program

#Id: 10421

#Unit 4. Cell Communication and Cell Signaling

Snail and Twist promote expression of genes involved in cell migration, loss of cell-cell adhesion, loss of cell polarity, and increase the production of proteases that digest the basement membrane

TLS Online TPP Program

#Id: 10422

#Unit 4. Cell Communication and Cell Signaling

TLS Online TPP Program

#Id: 10423

#Unit 4. Cell Communication and Cell Signaling

Tumor cells secrete a protein plasminogen activator that converts the serum protein plasminogen to the active protease plasmin.