A) 1 purin (360A+180G) : 1 pirimidin (180C+360T) B) 2 purin (360A+180G) : 1 pirimidin (90C+180T)
C) 5 purin (330A+120G) : 1 pirimidin (60C+30U)
D) 5 purin (330A+120G) : 1 pirimidin (60C+30T)
Ishlanishi: 1) N=AK*3 N=180*3=540N -1 ta ipdagi N lar
2) i-RNK da: G=4A G=4*30=120; S=G/2; S=120/2=60 U=30; A=540-(G+S+U) A=540-210=330 3) DNK da: U+A=A(T) 30+330=360A(360T)
G+S=G(S) 120+60=180G(180S)
4) Purin=A+G Purin=360A+180G Pirimidin=S+T Pirimidin=180S+360T Javob: A _____________________________ 226. DNK ning qo'sh zanjirida G nukleotidlari 40%ni tashkil
etadi. DNK dagi gen asosida sintezlangan oqsil 400 ta
aminokislotadan iborat bo'lsa, shu DNK qo'sh zanjiridagi pirimidin
asoslari sonini toping.
A) 600 B) 960 C) 1200 D) 320
Ishlanishi: 1) N=AK*3 N=400*3=1200N*2=2400N -2 ta ipdagi N lar
2) 2400---100%
G-x---40% G-x=(2400*40)/100=960N G-960=960-S
3) 960----40%
A-x---10% A-x=(960*10)/40=240 A-240=240-T
4) A+G=960+240=1200N Purin
5) S+T=960+240=1200N Pirimidin Javob: C _____________________________ 227. iRNK molekulasida A-20%, G-10%, U-40% bo‘lsa, teskari
transkripsiya jarayonida sintezlangan DNK qo‘sh zanjiridagi
guaninning foizini ko'rsating.
A) 30 B) 10 C) 20 D) 40 Ishlanishi: 1) i-RNK da: A-20%; G-10%; U-40%; S-?
S=100-(A+G+U)=100-(20+10+40)=100-70=30%-S
2) DNK da A(T)=(U+A)/2 A(T)=(20+40)/2=30%A(T) G(S)=(G+S)/2 G(S)=(10+30)/2=20%G(S) Javob: C _____________________________ 228. DNK ning qo‘sh zanjirida G nukleotidlari 40%ni tashkil
etadi. DNK dagi gen asosida sintezlangan oqsil 400 ta
aminokislotadan iborat bodsa, shu DNK qo‘sh zanjiridagi timin
nukleotidlari sonini toping.
