InterviewSolution
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InterviewSolution
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Question : Describe the T.S. oftestis and explain the process of spermatogenesis. |
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Answer» Solution :I. T.S. of testis: II. Process of spermtogenesis : (1) In the processof spermatogenesis , primordialgerm cellsor germinal cells ofthe seminifieroustubulespass throughthree phases, vizs, phase ofmultiplication, phase of growthand phase ofmaturation. (i) Multiplicationphase : Primordialgermcells undergomitoticdivisionsto producemany diploid (2n) SPERMATOGONIA . (ii) Growthphase :Spermatogonisum accumulatesnutrientsand growsin size,givingrise toprimaryspermatocyte (2n). (iii) Maturation phase :The primaryspermatocyteundergoesfirstmeioticdivisionor maturationdivision.Exchangeof geneticmaterialoccursbetweenhomologouschromosomes INEACH sper-matocyte. (2) Themeioticdivisiongives rise tosecondary spermatocytewhich is haploid(n).At the endof firstmeiotic divisiontwo secondaryspermatocytes are formedwhile at the end of secondmeiotic divisionfour haploidspermatidsare formed. (3) SPERMATIDS are nonmotile. They undergo spermiogenesisand form motilespermatozoan(sperm).The changestaking place duringspermiogeneisare as follows : (i)Increase in length . (ii) Formationof proxinaland distal centriole. (iii) Distal centriole formsthe axialfilament. The various STAGESOF spermatogenesis. 
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