Why is this extra control of two layers on trp operon needed?  The answer probably lies in the fact that repression of the trp operon is weak—much weaker.

TLS Online TPP Program

#Id: 1042

#Unit 5. Developmental Biology

Limb field - All the cells are capable of forming a limb on their own.

TLS Online TPP Program

#Id: 10073

#Unit 4. Cell Communication and Cell Signaling

Snail suppresses the expression of E-cadherin is associated with the EMT

TLS Online TPP Program

#Id: 9626

#Unit 4. Cell Communication and Cell Signaling

Following binding of an EGF ligand, the rate of endocytosis of HER1 is increased about tenfold, and only a fraction of the internalized receptors return to the plasma membrane; the rest are degraded in lysosomes.

TLS Online TPP Program

#Id: 3677

#Unit 3. Fundamental Processes

Some prokaryotic ORFs lack a strong RBS but are nonetheless actively translated Using the phenomenon of translational coupling.

TLS Online TPP Program

#Id: 2445

#Unit 3. Fundamental Processes

The b subunit of RNA polymerase is implicated by two types of mutation. 

First, mutations in the rpoB gene can reduce termination at a rho-dependent site. 

Second, mutations in rpoB can restore the ability to terminate transcription at rho-dependent sites in rho mutant bacteria.