Question

9, Explain how the behavior of chromosomes at metaphase I ensures the differential segregation of homologous chromosomes at anaphase I. 10. With reference to the type of cellular response that each elicits, contrast a mitogen, a growth factor and a survival factor.

Answer 1

A9 suring metaf wing metaphase 1, the kinetochone microtubule pull the su the sister chromatids back and forth untu they align along the equator of the cea cared equatoua plane There !Soň important checkpoint in the middle of mitosis called metaphase checkpoint during which the cell ensures that it 'Is vready to divide Once the den has established that all the chromosomes are properly aligned and that the kimetochores are correctly attached, the cell enters the fourth phase of mext phase of miltosts in onaphase In mieolie der division, the homologous chromosome purs align at the equatorial plane of dividing cells and each homologous pairs attach to spindle fibres produced by kimeto choses. After the chromosomes are correctly altached to the spindle fibres produced by kimetochores. ilt ensures that anaphase 1 can take place The homologous chromosomes are filled to opposite poles of the cell by spindle fibres during maphase 1

Mitogen I got Surrineal factor I Suruinal factors increase cell cyckis viegulated numbers by growth factor | Mitogen is a chemical I only a small substance that induces partion of cell el to begin cell dinsion Mitogen by growth factors inhibiting poptosis briggers the signal If the cells are deprived of transcution pathway grawth factors involving mitogen eat the cencepcle division or Qctwated protein kinase and enter 98 cull growth MAPK) leading to state grooth induces apoptosis factors promote mito eis exit fromgo, and cells undergo Entracelular factor that inhibit cell y Tallcycle