Ziziphi iimpawu zesakhiwo seesini zesini zesini?
Ngoko, i-spermatozoa, ngenxa yokuba kufuneka babe nokuhamba okuphezulu ngokuchumisa, iiseli ezincinci, umzimba wazo udibene. I-Sperm, ngokungafani ne-ovum, ayinayo i-cytoplasm eninzi. Iqulethwe yinxalenye ye-nucleus equkethe intloko, kunye neflagellum (umsila), leyo iyilungu layo lokunyakaza. Ukususela kwizinto ezibizwa ngokuthi i-subcellular izakhiwo kwi-spermatozoon, kukho i-mitochondria enika amandla ngamandla okunyakaza, i-acrosomal vacuole (equkethe i-enzymes yokuchithwa iiphetshana zeqanda elivuthiweyo), i-centriole ehamba phambili. Ubude obupheleleyo be-spermatozoon bungama-60 μm, apho umsila ungama-55 μm.
Xa ushiya ibhinqa yesini, isithengi, isidoda sinyanga, i. azinalo ukuhamba, kodwa zenziwe ngokusemthethweni. Ngaloo ndlela, abanalo ikhono lokutshala. Ukusetyenziswa kwamaseli wesini wesilisa kwenzeka kwinkqubo ye-vas deferens.
Ziziphi iimpawu zesakhiwo eziphawulekayo kwi-cell cell?
Inqamana yegciwane lesetyholongwane, iqanda, ngokungafani ne-spermatozoon, likhulu ngobukhulu kwaye ayikwazi ukuhamba. Ubukhulu bayo bufikelela kumamitha ayi-100-200 kumntu. Oku kuyingxenye ngenxa yeliqanda eligcinwe ukudibanisa i-trophic, eziyimfuneko nje ekuphuhlisweni kwembungu kwiindawo zokuqala. Kwakhona, inani elikhulu lezakhiwo ze-cytoplasm ekubunjweni kwayo kuyadingeka ukuze kusetyenziswe izizukulwana zokuqala zamaseli e-embryonic-blastomeres.
Iqanda leqanda, ngokungafani ne-spermatozoon, libhekiselwe kwinucleus enkulu, apho i-euchromatin (i-nucleoprotein yendawo esondeleyo kwinqanaba le-nucleus, echithwe kakhulu, ejongene nokutshintshwa kolwazi lwezofuzo) iqulethe kwaye iqulethe i-cytoplasm enkulu. Ngaloo nto i-mitochondria kuyo ingakanani ubuncinane, obangelwa ukuhamba okuphantsi kweeseli zesini zesini. Kukwafanelekile ukuba uqaphele ukuba iisetyhini zesini zesini zabesetyhini azikho. Oku kungabikho, mhlawumbi, isigaba sokuqala sokubunjwa kwabo, kwinqanaba le-ogony. Ngokuqhelekileyo, ii-ovules zixhomekeke ngokusondeleyo kunye neeseli ze-somatic, eqinisweni, zakha i-membrane yokudibanisa kunye ne-epithelial malunga neseli nganye yesini. Olu bunzima lwalubizwa ngokuba yi-ovarian follicle. Isakhiwo saso siyanzima kwinkqubo ye- oogenesis .
Zonke iintlukwano zeqanda ezivela kwidoda azikwazi ukufakwa kwitheyibhile enye, ngoko ke iileli ezimbini ezahlukeneyo.
Ziziphi iimeko eziphambili phakathi kweeseli zentsholongwane?
Xa ndixelele malunga nawaphi amaqanda ahluke kwi-spermatozoa kwaye kutheni, ukuququzelela, ndingathanda ukubhala uluhlu lwabo oluphambili. Phakathi kwabo kukho:
- isethi ye-chromosome (kwi-spermatozoa- X chromosome, kwi-oocytes-U);
- Uhlobo oluthile lwe-nyukliya-cytoplasmic (phezulu kwi-spermatozoon, ephantsi kweqanda);
- ubungakanani kunye nesimo (esikhulu kunye nesalathisi ngokuchasene namancinci kunye nendawo);
- idiza inomzimba.
Ngaloo ndlela, kunokuthiwa ukuba ukungafani okuphambili kwe-spermatozoon evela kwiqanda kusekwisakhiwo, ngenxa yobungakanani bezinto eziphilayo ezabelwe zona.