Action potentials are propagated down the motoneuron, depolarize each adjacent region to threshold. Finally, the presynaptic terminal is depolarized, and this depolarization causes voltage-gated Ca2+ channels in the presynaptic membrane to open.

TLS Online TPP Program

#Id: 1909

#Unit 4. Cell Communication and Cell Signaling

TLS Online TPP Program

#Id: 3064

#Unit 10. Ecological Principles

 Tropical islands have greater c values than temperate ones.

TLS Online TPP Program

#Id: 9616

#Unit 4. Cell Communication and Cell Signaling

Homodimerization

HER1 directly binds EGF which leads to formation of a homodimer of the HER1 extracellular domain

TLS Online TPP Program

#Id: 6046

#Unit 10. Ecological Principles

TLS Online TPP Program

#Id: 6881

#Unit 3. Fundamental Processes

This mechanism is a key feature of Polycomb repression, which is maintained through successive cell divisions for the life of an organism (~100 years for some vertebrates, 2000 years for a sugar cone pine!)