Abituriyentlarga qulayliklari

Ishlanish:
X+Y=440
X-Y=200
X=320 A va T
Y=120 G va S
320×2=640
120×2=240 umumiy 880 ta nukleotid
640×2=1280 ta h bog
240×3=720 ta h bog
880-308=572 ta
240-308=68
1280:2000=64%
308:880=35%
64-35=29%
Javob: B) 29 %

4. (A+T)-(G+S)=50 va umumiy vodorod boglar soni 425 bolsa, DNK fragmenti uzunligini aniqlang.(qo`shni nukleotidlar orasidagi masofa 0,34nm)

A) 59,5 nm B) 50,4 nm C) 61,2 nm D) 45 nm
Ishalanishi:
2x-2y=50 farq
2x+3y=425 vodarod bog'lar
X=100
Y=75
100+75=175×0,34=59,5 nm
Javob: A) 59.5 nm

5. DNK dagi H2 bog'lar soni RNK dagi fosfodiefir bo'g'lar sonidan 331taga peptid bog'lar sonidan 451taga ko'p bo'lsa, timinlar sonini toping.

A)30. B)40. C)50. D)60
Yechimi:
2x + 3y = x + y - 1 +331
2x + 3y = x + y
-------- -1 +451
3
2x + 3y = x + y =330
x + 2y = 330

2x + 3y = 0,3333x +0,333y = 450

1,66666x + 2,66666y = 450

x + 2y = 330. / 1,666x

1,666x + 2,666y = 450

0,66666y =100

y = 150
x = 30
Javob: A) 30

6. DNK dagi a.b.c genlardan xosil bolgan oqsil monomerlarining umumiy soni 315ta b gendan xosil bolgan oqsil monomerlar soni a gendan xosil bolgan oqsil monomerlar sonidan 10taga kop.c gendan xosil bolgan oqsil monomerlar sonidan 1.25 martaga kam DNK ning a genidagi A nukleotidlar soni bilan dnk ning b genidagi G nukleotidlar nisbatini aniqlang(a genda A:G 1:3.5 bgenda T:S 1:1.5 c genda A:S 2:1 ga teng)

A)1:2. B)3:1 C)2 : 6 D) 1:1
Yechimi:
a. b. c
x-10. x. 1,25

x - 10 + x + 1,25x = 315

x + x + 1,25x = 325
3,25x = 325
x = 100

100 - 10 = 90. 90x3 = 270 Nukleotid.

270
------ = 60(Adenin)
4,5

100 x 3 = 300.

300
------- = 120(Adenin b DNK)

2,5

120 x 1,5 = 180( b dagi Guaninlar soni)

60 : 180
1 : 3