2 - Usul:
1) 2x+3y=810
2x 1
------- = ---------
3y 1,25
x = 180 y= 150
Javob: B) 220
23. Bir molikula oqsil sinteziga javobgar bo'lgan DNK fragmentidagi guanin va sitozin nukleotidlari orasidagi vodarod bog'lar soni bilan, adinin va timin o'rtasidagi vodarod bog'lari soni yeg'indisi 750 ga, ayirmasi esa, 150 ga teng bo'lsa, DNK fragmentidagi jami nukleotidlar sonini aniqlang.
A) 450 B) 600 D) 650 D) 500 DTM_2017
Yechish :
1) x + y=750
x - y=150
X=450 G va S
Y=300 A va T
2) 450:3=150 G va S bitta zanjirda
3) 300:2=150 ta A va T bitta zanjirda
4) 150 × 2=300 ta G va S
5) 150 × 2=300 ta A va T
6) 300 + 300=600 ta jami nukleotid
Javob: B) 600
24. (A+T)-(G+S)=16 va umumiy vodorod bogʼlar soni 666 boʼlsa, DNK fragmenti uzunligini aniqlang.(qo`shni nukleotidlar orasidagi masofa 0,34nm)
A) 91,12 B) 50,4 C) 61,2 D) 45 2017_DTM
Yechish:
1) 2x-2y=16
2x+3y=666
X=138 Y=130
2) 138+130=268 3) 268 x 0,34=91,12
Javob: A) 91,12
2 mol sut k-ta --------- 36 ATF
20 = x ---------------- 360 ATF
26. 38400 molekular ogʼirlikdagi oqsil sintezlashda i-RNKning 20% ishtrok etmagan boʼlsa, oqsil sintezida ishtrok etgan DNK dagi nukleotidlar yigʼindisini toping.(oqsildagi bitta aminokislota ogʼirligi 120)
A) 2400 B) 3200 C) 3600 D) 4200 DTM_2017
Yechimi
1) 38400/120=320 ta aminokislota 2) 320•3=960 ta nukleotid
3) 960 ----------- 80 %
1200 = x ------- 100% 4) DNK da 1200•2=2400 Javob: A) 2400
28. DNK dagi a,b,c genlardan hosii bo’igan oqsil monomerlarining umumiy soni 315 ta,
b gendan hosil bo'lgan oqsildagi monomerlar soni a gendan hosil bo'lgan oqsil monomerlar sonidan 10 taga ko'p, c gendan hosil bo’lgan oqsil monomerlar sonidan esa 1,25 marta kam. DNK ning b genidagi umumiy vodorod bog’lar sonini aniqlang (Nukleotidlar nisbati
a genda A/G=1/3,5 b genda S/T=1/1,5 c genda A/S=2/1 ga teng)
A) 750 B) 875 C) 720 D) 30
Yechish :
1) a = x
b = x+10
c = (x+10)1,25
2) x+(x+10)+(x+10)•1,25=315
x=90
3) a genda nukleotid
90•3=270
A/G=1/3,5 270/4,5=60 A
A = 60 G = 210
4) b genda nukleotid
100•3=300
S/T=1/1,5 300/2,5=120 S
S = 120
T = 180
5) c genda nukleotid
125•3=375
A/S=2/1 375/3=125 S
A = 250
S = 125
Bizdan b gendagi [H] bogʻlar soʻralgan
180•2=360
} 720
120•3=360 Javob: C) 720
30. Maʼlum sharoitda 105,4 nm uzunlikdagi DNK malekulasi BamHI restiriktaza fermenti taʼsirida ABCD boʼlaklar ga boʼlindi Hosil boʼlgan barcha DNK malekulasidagi vodorod bogʼlar soni dastlabki vodorod bogʼlar sonidan 3,75% ga kam boʼlsa dastlabki DNK malekulasidagi G-S orasidagi vodorod bogʼlar sonini toping.
A)540 B)522 C)260 D)248 DTM_2017
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