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: 8908

#XL - T Zoology

Phosphatase is recruited to centromeric by the Shugoshin family of proteins

TLS Online TPP Program

#Id: 8909

#XL - T Zoology

Separase cleaves centromeric cohesin, triggering the onset of anaphase, releasing the sister chromatids

TLS Online TPP Program

#Id: 8910

#XL - T Zoology

Before anaphase Separase is inhibited by the binding of the protein securin and Mitotic CDKs.

TLS Online TPP Program

#Id: 8911

#XL - T Zoology

TLS Online TPP Program

#Id: 8912

#XL - T Zoology

When all the kinetochores have properly attached to spindle microtubules, APC/CCdc20 directs ubiquitinylation of securin and mitotic cyclins

TLS Online TPP Program

#Id: 8913

#XL - T Zoology

APC/CCdc²⁰ is inhibited by a checkpoint pathway that ensures that anaphase is not initiated until all chromosomes have achieved proper attachment to the mitotic apparatus.