This combination of two positive feedback loops:

one that activates a CDK1 activator (Cdc25C)

one that inhibits a CDK1 inhibitor (Wee1)

results in the abrupt and irreversible transition from G2 into mitosis.

TLS Online TPP Program

#Id: 2373

#Unit 5. Developmental Biology

In regenerating planaria, Notum is activated in the anterior-facing blastema, which generates a head.

TLS Online TPP Program

#Id: 9461

#Unit 4. Cell Communication and Cell Signaling

Active JAK kinase phosphorylates several tyrosine residues in the receptor’s cytosolic domain and activates a STAT transcription factor that moves directly to the nucleus

TLS Online TPP Program

#Id: 685

#Unit 3. Fundamental Processes

Attempts to repair telomeres in the DSBR manner as double-stranded DNA breaks would lead to chromosome fusion events, which eventually result in random chromosome breaks.

TLS Online TPP Program

#Id: 117

#Unit 5. Developmental Biology

Responder, 

the cell or tissue being induced.

TLS Online TPP Program

#Id: 635

#Unit 3. Fundamental Processes

Adenine is deaminated to hypoxanthine.