Overdominance the heterozygote has higher fitness than the  fitnesses of the two homozygotes

Underdominance, in which the heterozygote has lower fitness than both homozygotes.

Directional selection leads to fixation of the favored allele and elimination of the other allele, as  long as no other evolutionary forces act on the population.

TLS Online TPP Program

#Id: 9324

#XL - T Zoology

Rhodopsin kinase, a member of the GRK family of kinases catalyzes phosphorylation of activated rhodopsin

TLS Online TPP Program

#Id: 9325

#XL - T Zoology

Each opsin molecule has multiple principal serine and threonine phosphorylation sites on its cytosol-facing C-terminal segment.

TLS Online TPP Program

#Id: 9326

#XL - T Zoology

TLS Online TPP Program

#Id: 9328

#XL - T Zoology

Arrestin binds tightly to rhodopsin only when rhodopsin kinase has phosphorylated a sufficient number of C-terminal serines and threonines.

TLS Online TPP Program

#Id: 9329

#XL - T Zoology

The entire process of rhodopsin phosphorylation and its inactivation by arrestin is fast completed within 50ms. 

TLS Online TPP Program

#Id: 9330

#XL - T Zoology

Phosphorylated rhodopsin is restored to its light-sensitive state (R) during dark adaptation by a specific rhodopsin phosphatase