Test topshiriqlari, masalalar to’plami va nazariy ma’lumotlar. Genetika

AA- genotipli organizm bir xil gameta hosil qiladi ya’ni A
Aa – genotipli organizm ikki xil gameta hosil qiladi ya’ni A, a
AaBB – ikkita belgisi bilan farq qiluvchi genotipli organizm ikki xil gameta hosil qiladi ya’ni AB, aB
Duragaylarda hosil bo’ladigan gametalarni hisoblab toppish mumkin.
Buning uchun quyidagi fofmuladan foydalaniladi 2ⁿ Bu yerda “n” geterozigotalar
soni (Aa).
1. AaBB duragayda 2¹=2, ikki xil gameta hosil bo’ladi (AB, aB)
2. AaBb duragayda 2²=4, to’rt xil gameta hosil bo’ladi (AB, Ab, aB, ab)
3. AaBbCc duragayda 2³ =8 , sakkiz xil gameta hosil bo’ladi. (ABC, ABc, Abc, AbC, aBC, aBc, abC, abc)

GAMETALAR OLISH

1. Quyidagi genotiplar necha xil gameta hosil qiladi?

a) AABBCCDD; b) aabbccDdmm;
c) AabbCCee; d) AaBB; e) AaBBCcDdmm
A) a-1; b-2; c-2; d-2; e-8
B) a-1; b-16; c-4; d-2; e-16
C) a-1; b-1; c-2; d-2; e-16
D) a-1; b-1; c-2; d-2; e-4


Yechim:
a) AABBCCDD faqat bitta gameta chiqadi (1)
b) geterogametalar soni bitta aabbccDdmm 2¹=2
c) geterogametalar soni bitta AabbCCee
2¹=2
d) geterogametalar soni bitta AaBB 2¹=2
e) geterogametalar soni uchta AaBBCcDdmm
2³=2*2*2=8


demak, a-1; b-2; c-2; d-2; e-8 A-variant muqobil hisoblanadi.

2. Qanday genotiplardan 4 xil gameta olish mumkin?

1) AaBb; 2) AaBBCC; 3) AaBbCC; 4) AaBB;
5) AABbCcDd; 6) AABb; 7) AaBBCcDD;
8) aaBb; 9) AaBBccDd
A) 2, 4, 5, 9 B) 1, 2, 7, 8
C) 1, 2, 3, 4 D) 1, 3, 7, 9