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267. DNK zanjiri ААТSАSGАТSSТ
nukleotidlari ketma-
ketligiga ega. Oqsil hosil bo`lishi uchun ishtirok etadigan t-RNK
xillarini
belgilang
A) ААU, SАS, GАU, SSU B) ААU, GУG, SUА, АGG
C) ААU, SАS, GАU, SSА
D) UUА, GUG, SUА, GGА
Ishlanishi:
1) DNK 1-ipda: T TAGTG S TAGGA
DNK 2-ipda: ААТ SАS GАТ SS Т
i-RNK da:
UUAGUGSUAGGA Javob: D
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268. UUAGSSGAU ushbu RNK
dan teskari transkriptaza
vositasida sintezlangan DNK da nechta H bog’lar bor
A) 22 B) 12 C) 44 D) 10
Ishlanishi:
1) i-RNK da: UUAGSSGAU
DNK 1-ipda:
AAT SGGSTA
DNK 2-ipda: T TAGS SGAT
2) A-T=5; G-S=4 H=2A+3G H=(2*5)+(3*4)=
22 Javob: A
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269. DNK molekulasida 880 ta guanin nukleotidi mavjud bo`lib,
ular barcha nukleotidlarning 22 % ni tashkil etadi. Sitozin
nukleotidlari soni DNK ning uzunligini aniqlang.
A) 1120; 680 B) 2240; 880
C) 1760; 880
D) 880; 680
Ishlanishi:
1) G-22%=22%-S
G-880=880-S 44%=G+S 100-44=56
2) 56%=A+T 56/2=28 A-28%=28%-T
880---22%
A---28% A=(880*28)/22=1120N
3) A+G=880+1120=2000N -DNK ning 1 ta ipidagi
N lar
4) L=N*0,34nm L=2000*0,34nm=
680nm Javob: D
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270. DNK molekulasida 28450 H bog’i bor. Undagi A umumiy
nukleotidlarni 25 % ini tashkil etadi. Ushbu DNK ning uzunligini
toping ?
A) 1934,6
B) 3869,2 C) 9673 D) 5803,8
Ishlanishi:
1) A=T => 25%=A-T=G-S=25%
2A+3G=H
2A+3A=28450 5A=28450
A=5690=T=G=S
2) 1 ta zanjirdagi jami nukleotidlarni
topish uchun A ga G ni
qo’shamiz: A+G=5690+5690=11380N
3) L=N*0,34nm L=11380*0,34nm=
3869,2nm Javob: B
