_____________________________ 193. Teskari transkripsataza fermenti yordamida i-RNK dan
DNK sintezlandi i-RNK da U=20% bo`lib, DNK qo`sh zanjirining
15% ni timin tashkil qilasa i-RNKda A-necha foizni tashkil qiladi?
A)10 B)15 C)20 D)30
Ishlanishi: 1) (i-RNK)U+A=DNK(A+T)
2) 20U+xA=15A+15T A=T
20+x=15+15
x=30-20
x=10 i-RNK-A=10% Javob: A _____________________________ 194. Teskari transkriptaza fermenti yordamida i-RNK dan DNK
sintezlandi. i-RNK da U=55% bolib DNK qo`sh zanjirining 35% ni
timin tashkil qilsa, i-RNK da necha foiz A bo`ladi?
A)15 B)55 C)20 D)35
Ishlanishi: 1) (i-RNK)U+A=DNK(A+T)
2) 55U+xA=35A+35T A=T
55+x=35+35
x=70-55
x=15 i-RNK-A=15% Javob: A _____________________________ 195. DNK qo`sh zanjirida 180ta vodorod bog` bo`lib ulardan 1/3
G-S orasida bo`lsa DNK fragmenti uzunligini aniqlang(qo`shni
nukleotidlar orasidagi masofa 0,34nm)
A)27,2 B)17,8 C)30,6 D)71,4
Ishlanishi: 1) 3---180H
1---x x=180/3=60H -bu G va S orasodagi H bog’lar
2) 180-60=120H -bu A va T orasidagi H bog’lar
3) G va S orasida 3 ta H bog’ bo’lgani uchun: 60/3=20 G-S
4) A va T orasida 2 ta H bog’ bo’lgani uchun: 120/2=60 A-T
5) (A+G)=N 60+20=80
6) L=N*0,34nm L=80*0,34=27,2nm Javob: A _____________________________ 196. DNK qo`sh zanjirida 180ta vodorod bog` bo`lib ulardan 1/3
G-S orasida bo`lsa DNK fragmentidagi fosfodiefir bog`lar sonini
aniqlang(qo`shni nukleotidlar orasidagi masofa 0,34nm)
A)158 B)178 C)79 D)89
Ishlanishi: 1) 3---180H
1---x x=180/3=60H -bu G va S orasodagi H bog’lar
2) 180-60=120H -bu A va T orasidagi H bog’lar
3) G va S orasida 3 ta H bog’ bo’lgani uchun: 60/3=20 G-S
4) A va T orasida 2 ta H bog’ bo’lgani uchun: 120/2=60 A-T
5) (A+G)=N 60+20=80N –bu 1 ta ipdagi N lar soni
6) 2N=2*80=160
7) F=2N-2 F=160-2=158F Javob: A
