YE POSITIONS KYUN? Anthers upar aur exposed hote hain taaki pollen aasani se pick ho sake; stigma sticky hota hai aur aise position mein hota hai ki brush ho sake taaki pollen pakad sake. Flower ki shape mein sab kuch ek delivery strategy hai.
Do types — is basis par ki kiske stigma ko pollen milta hai:
Type
Pollen jaata hai...
Genetic result
Self-pollination
same flower / same plant ko
kam variation, reliable
Cross-pollination
alag plant (same species) ko
zyada variation, vector chahiye
Cross-pollination KYUN important hai? Do parents ke DNA ko mix karna → genetic variation → agar environment badal jaye to better survival (natural selection ke paas kaam karne ka material hota hai).
Pollen ek compatible stigma par girta hai (sticky → pakad leta hai).
Grain sugar/water absorb karta hai → style se neeche ek pollen tube ugata hai.
Tube male gamete nucleus ko ovule ki taraf carry karta hai.
Tube ovule mein ghusta hai; male gamete female egg cell nucleus ke saath fuse hota hai → yahi fusion fertilization hai.
Fertilized egg = zygote → divide hota hai → embryo.
Fertilization ke baad (KAUNSI cheez KYA ban jaati hai):
Ovary fruit KYUN ban jaati hai: fruit seed(s) ko protect karta hai aur aksar dispersal mein bhi help karta hai (jaanwar khate hain, hawa le jaati hai) — offspring ko parent se door spread karta hai taaki competition na ho.
Plants partner dhundne ke liye chal nahi sakte, isliye wo ek clever mail system use karte hain. Anther ek dusty stamp pad jaisa hai jo yellow pollen banata hai. Ek bee (ya hawa) wo postman hai jo us pollen ko doosre flower ke sticky landing pad, yaani stigma, tak carry karta hai — yeh delivery pollination hai. Phir pollen egg tak pahunchne ke liye flower ke andar ek tiny straw ugata hai, aur male bit slide hokar egg se milta hai — yeh milna fertilization hai. Joined cell ek baby plant mein grow hoti hai jo seed ke andar pack hoti hai, aur uske aas-paas ki wall phool kar fruit ban jaati hai. Toh: postman deliver karta hai (pollination), phir do cells haath milate hain (fertilization), phir seed paida hota hai.
