Principles of Inheritance
Law of Segregation
Har gene ki do copies hoti hain, ek har parent se. Jab egg ya sperm cells banti hain, tab ye do copies alag ho jaati hain, aur har cell ko sirf ek copy milti hai.
Ek gene do copies me aata hai. Jab body gametes (egg ya sperm cells) banati hai, to do copies alag ho jaati hain. Isliye har gamete ko sirf ek copy milti hai, randomly chuni hui. Baad me fertilisation do gametes ko jodta hai aur ek nayi pair ban jaati hai. Yahi clean split poora law hai.
Yahaan students galti karte hain
Students aksar sochte hain ki do copies mix ho jaati hain, ya ek hi gamete me chali jaati hain. Aisa nahi hota. Wo poori tarah alag hoti hain, ek copy per gamete. Isiliye ek tall pea plant jo ek hidden ‘short’ copy rakhta hai, phir bhi short offspring de sakta hai. Wo hidden copy hamesha wahaan thi, aur akeli gamete me jaati hai.
Yaad rakho
Do copies andar. Ek copy bahar. Har gamete, hamesha.
Exam me kaise kaam aata hai: F₂ generation ka 3 : 1 ratio seedha isi se aata hai. Split samajh lo, to ratio ratta maarne ki zaroorat nahi, khud nikaal loge.
Ek quick check
Tt genotype wala pea plant gametes banata hai. Kitni gametes me T allele hoga?
- ASaari
- BAadhi
- CEk chauthai
- DKoi nahi