A) 18,75% B) 25% C) 60% D) 40%
Ishlanishi: 1) Demak, DNK ning 2 ta ipida N=6400 bo’lsa, T=1600, 2-ipda
G=1300:
DNK dagi jami G ni topamiz: har doim A miqdori T ga, G
miqdori S ga teng.
6400 --- 100%
1600 ---x x=(1600*100)/6400 x=25%
T-1600-25%=25%-1600-A ikkalasi 50% ni tashkil etadi.
2) 100%-50%=50% Demak, 50% i G va S ni tashkil etishi
kerak va ular:
G-1600-25%=25%-1600-S ni tashkil qiladi => A=T=G=S
3) Jami G dan 2-ipdagi G ni ayiramiz va bunda 1-ipdagi G kelib
chiqadi: 1600-1300=300
4) Jami G % izidan 1-ipdagi G % izini topamiz:
1600 --- 100%
300 --- x x=(300*100)/1600 x=18,75% Javob: A ____________________________
45. DNK molekulasini ikki ipida 3200 ta nukleotid bor. Umumiy
nukleoitlarni 25 % i S. 1-ipda timin nukleolidini 70 % i, guaninlarni
esa 30 % i joylashgan. DNK ning 1-ipidan sintezlangan i-RNK dagi
purin asoslari sonini toping
A) 1600 B) 1120 C) 480 D)560
Ishlanishi: 1) 3200 --- 100%
x(S) --- 25% x=(3200*25)/100 x=800
S-800-25%=25%-800-G ikkalasi 50% ni tashkil etadi.
2) 100%-50%=50% Demak, 50% i G va S ni tashkil etishi
kerak va ular:
A-800-25%=25%-800-T ni tashkil qiladi => A=T=G=S
3) Jami G dan 1-ipdagi G ni topamiz:
800 --- 100%
x --- 30% x=(800*30)/100 x=240 G=240
Jami T dan 1-ipdagi T ni topamiz:
800 --- 100%
x --- 70% x=(800*70)/100 x=560 T=560
4) Bu ipdagi T=560 bo’lsa, A=240 ga; G=240 bo’lsa, S=560
ga teng bo’ladi.
DNK da AGST i-RNK da USGA U=240; S=240; G=560; A=560 5) i-RNK da Purin=A+G bo’ladi: 560+560=1120 Javob: B ______________________________
46. DNK molekulasimng ikki ipida 12800 ta nukleotid bor
bo’lib, shulardan 1600 tasi timin. Agar guaninlarni 1920 tasi 2-ipda
joylashgan bo’lsa, DNK molekulasidagi adeninlar umumiy
nukleotidlarni necha foizini tashkil etadi
A) 30% B) 15% C) 20% D) 12,5 % Ishlanishi: 1) Demak, DNK ning 2 ta ipida N=12800 bo’lsa, T=1600, 2-ipda
G=1920
DNK dagi jami G ni topamiz: har doim A miqdori T ga, G
miqdori S ga teng.
12800 --- 100%
(A-T)1600 --- x x=(1600*100)/12800 x=12,5% Javob: D ____________________________
47. Qo’shni nukleotidlar orasidagi masofa 0,34 nm. Sintezda 689
ta aminokislola ishtirok etgan. Shu oqsilni sintez qilgan i- RNK ning
uzunligini toping.
A) 708,72 B) 2067 C) 702,78 D) 234,26
