Kendrak 

Kendra ke Charon or dohre parat ka ek satar hota hai jise kendrak jhilli kahate Hai. Kendrak jhilli mein छोटे-छोटे chhidra hote Hai. Ine chitron ke dwara kendrak ke andar ki koshika drav Kendra ke bahar Ja pata hai. 

Kendrak mein kormosouce hota hai Jo koshika vibhajan ke samay chhudakar dikhai padte Hai. Kormosoce main anuwanshik gunon ki jo suchna Hoti Hai vah Mata pita Se (DNA)( डिऑक्सी रायपुर न्यूकलीक अम्ल) Anu ke roop mein ungali संतति main jaate Hai.

       Koshika dravya 

Jab humne pyaj ki jhilli tatha manushya ke gal ki koshikaon ki slide Ko dekha tab hamen pratyek koshika Main ek bada Kshetra dikha Jo koshika jhilli se gira hua tha is Kshetra mein bahut halka dhabba tha ise koshika dravya kahate Hai.

        Koshika angk 

Pratyek koshika ke Charon or apni jhilli Hoti Hai jisse ki usmein sthiti padarth pahna paryavaran Se Alag Rahe padi tatha jatil koshikaon jismein Bahu koshika jio ki koshikayen bhi Shamil Hai upcharik kriyaon ki bahut avashyakta hoti hai. Jisse ki vah jatil sanrachna tatha karya ko sahas De sake.