Lateral inhibition via horizontal cells in the mammalian retina ________.

TLS Online TPP Program

#Question id: 8714

#Unit 9. Diversity of Life Forms

The reason that paralogous genes can diverge from each other within the same gene pool, whereas orthologous genes diverge only after gene pools are isolated from each other, is that ________.

TLS Online TPP Program

#Question id: 30048

#Unit 5. Developmental Biology

Which of the following follows the phenomena of harmonious equipotential system?

TLS Online TPP Program

#Question id: 6992

#Unit 5. Developmental Biology

Epimorphosis is regeneration through:

TLS Online TPP Program

#Question id: 19098

#Unit 4. Cell Communication and Cell Signaling

Quorum sensing in E. carotovora is mediated by

TLS Online TPP Program

#Question id: 2863

#Unit 2. Cellular Organization

The promoter of the araBAD operon from E. coli is activated in the presence of arabinose and the absence of glucose and directs expression of genes encoding enzymes required for arabinose metabolism. Unlike the cases of lac and gal genes, where a repressor and an activator work together, here two activators work together: AraC and CAP

+ arabinose	AraC binds that sugar and adopts a configuration that allows it to bind DNA as a dimer to the adjacent half-sites, araI1 and araI2
– arabinose	the AraC dimer adopts a different conformation and binds to araO2 and araI1, there is no monomer at site araI2, and so the protein cannot activate the araBAD promoter (araPBAD). This promoter is also controlled by CAP.