RESTING 

 CONDITION 



PROPHASE - 

 STAG E S 



PRIMARY 

 SPERMATOCYTE 



■•*•*** homologue 



FROM ONE 



PARE NT 



HOMOLOGUE 



FROM OTHER 



P4R ENT 



SECOND Jii^ 



M E I T I C ^"^C»^ 

 DIVI SION ^ 



(1^ (m f1^ fit: 



Fig. 67. Diagrammatic representation of the nuclear changes occiirrmg during meiosis 

 in spermatocyte and oocyte. Six chromosomes, representing three homologous pairs, are 

 used. Observe the effects of the crossing over of parts of chromatids. The diplotene con- 

 dition of oocyte depicted by arrows and tfie enlarged nucleus. 1 he haploid condition is 

 shown in each of the spermatids or in the egg and its three polocytes. 



128 



