Giao t^ thiJ nhat chiJa ca 2 NST trong cap tiTdng dong: — = 28%. 34%+ 22%
A = T = 28% X 2 X 6.10*" = 3360000 nucleotit r;.;''' i t i )
G = X = 6 X 10^ - 3360000 = 2640000 nucleotit , , t ; • (jiao tuf thi? hai khong CO NST nao cua cSp tiTdng dong: i : ,
A = T = G = X = 0 nucleotit ' i M ^ ' i v v s / J
B^i 15: Mot cap NST tu'dng dong, moi NST gom 5 doan tirc:fng tfng: tfng vdi NST
thtf nhat c6 cac doan 1, 2, 3, 4, 5. NST thi? hai c6 cac doan a, b, c, d, e. TiJf te' bao chiJa cap NST co tha'y xua't hien:
1. Giao tuf chu'a NST c6 cac doan 1, 2, 3, d, e. '; 2. Mot nhom te'bao chu'a NST c6 cac doan 2, 3, 4, 5. 2. Mot nhom te'bao chu'a NST c6 cac doan 2, 3, 4, 5.
3. Mot nhom te'bao chu'a NST co cac doan 1, 2, 3,4,5. 1, 2, 3,4,5 vti a, b, c, d, e.
Gidi thich sir hinh thanh cac nhom to' bao tren.
HUiing ddn
1. D6 la giao tuf hinh thanh do si/ trao doi cheo giffa cac NST trong cap tufdng dong. tufdng dong.
2. Do la hien tiTdng dot bie'n cau true NST dang mat doan. 3. Do la hien tiTdng dot bie'n the lech bc)i (di boi). 3. Do la hien tiTdng dot bie'n the lech bc)i (di boi).
Bai 16: Cl mot loai sinh vat, gia thie't moi cap NST tiTdng dong deu chu'a c^c cap
gen di hdp. Khi khong c6 hien tifdng trao doi doan va dot bie'n thi so loai tinh trilng sinh ra nhieu nhat bang 256.
1. Bo NST liTdng boi cua loai co bao nhieu NST.
2. Trong cac cSp NST lu'cfng dong, neu co 1 cap NST xay ra trao doi doan tai 1 diem thi so' loai tinh trung cua loai co the tang them bao nhieu? 1 diem thi so' loai tinh trung cua loai co the tang them bao nhieu?
Hudngdp
1. Bo NST lircTng boi cua loai:
2^ = 256 => k = 8. Vay 2n = 16. " '
2. Mot Cclp NST trao doi doan tai 1 diem se tao ra:
4 X 2^ = 512 loai tinh irijng. ' *
Do do tang them: 512 - 256 = 256 loai tinh triing.
Bai 17: Xet ba cSp NST tiTdng dong ciia ngirdi. Cap NST 21 chu'a m6t cap gen
di hdp, cap NST 22 cMa hai cap gen di hdp va cap NST 23 chuTa mot cap gen
dong hdp.
1. Kieu gen cua 3 cap NST tiTdng dong do co the viet nhiT the' n^o?
2. Khi giam phan binh thufdng, thanh phan gen trong moi loai giao lit sinh ra
fcdc kieu gen noi tren nhiT the nao? ,y! ' • %
Ca'm nang ti; 6n va luy^n thi Sinh hpc - Phung Duy Ddng HUdng dan 1. Kieu gen: •J Aa — X ^ X ' ^ (1) : ^ Aa — X ' ^ X ^ (2) bd bD Aa — X ^ X " - - (3) Aa — X ' = X ' = (4) bd bD ' f i-i
2. Thanh phan gen trong moi loai giao tu'binh thirdng: + K i e u g c n ( l ) va(2): + K i e u g c n ( l ) va(2):
Khi giam phjin khong c6 hoan vi gen deu cho 4 loai giao tuf (hpc sinh tu" viet). - Khi giam phan c6 hoan vi deu cho 8 loai giao tuf:
A BD X ^ A bd a BD X ^ a M X'^ A Bd X'', A bD X''. a Bd X'', a bD X^ + Kieu gen (3) va (4): viet tiTcfng tuf nhu" tren.
Bai 18: Tong ham ItfcJng A D N cua cac te bao sinh tinh triing va cac te bao sinh
triJng d ruoi giam la 68pg (picrogam) tong ham lifdng A D N c6 trong tat ca cac loai tinh triing duTdc tao thanh nhieu hdn tong ham liTdng A D N trong ta't ca cac tru-ng diTdc tao thanh la 126pg. Biet rang tat ca cac triJng deu du-pc thu tinh. Ham liTcJng A D N c6 trong moi te bao 2n cua ruoi giam d trang th^i chi/a nhan doi bang 2pg.
1. Xac dinh so Ian nguyen phan lien tiep cua moi te bao sinh due diTc va te' bao sinh due cai ban dau (cac te' bao sinh due nay da sinh ra cac te bao sinh tinh bao sinh due cai ban dau (cac te' bao sinh due nay da sinh ra cac te bao sinh tinh trung va te'bao sinh triJng noi tren)
2. Ne'u tat ca cac hdp tu" du'ctc hmh thanh deu trai qua mot so Ian nguyen phan lien tiep nhu" nhau va tong so' ham lifcJng A D N chiJa trong tat ca cac te bao con lien tiep nhu" nhau va tong so' ham lifcJng A D N chiJa trong tat ca cac te bao con duTdc sinh ra sau nhffng Ian nguyen phan ay la 256pg thi moi hdp tuT da nguyen phan lien tiep may Ian?
Hudng dan
1. Trirdc khi phan bao deu c6 hien tiTdng NST nhan doi lam cho ham liTcJng
A D N tang gap doi 2pg x 2 = 4pg. Goi x la so te'bao sinh due diTc 2n va y la so'te
bao sinh due cai 2n ta c6 he phu'cfng trinh:
;T 2x + 2 y - 6 8 1 x = 32 - 2^
4 x - y = 1 2 6 P y = 2 = 2 ' i / . :
' ' • Do do te bao dinh due diTc 2n da nguyen phan 5 Ian lien tiep. Te bao sinh due cdi 2n da nguyen phan I Ian. , fg,.
2. So' Ian nguyen phan cua moi hdp tuT:
Hai te bao sinh due cai giam phan cho 2 tnJng deu diTdc thu tinh cho 2 hdp tuf. M o i hdp tuf da cho so te bao con la: — = 128
66
Cty TNHH MTV DVVH Khang Vigt
X - ™ 128 ^ . r>(,
So te bao con 2n: — - = 64 = 2
Do do m6i hdp tu: da nguyen phan lien tiep 6 ddt.
pai 19= Xet 2 cSp NST thufdng cua mot te bao sinh due c6 ehtfa thanh phan gen
ab deF ' -
1. Te bao sinh due do eo the cho bao nhieu kieu giao tuf khae nhau? Viet thanh phan cua moi giao tuf do (khong c6 trao doi doan va dot bie'n). thanh phan cua moi giao tuf do (khong c6 trao doi doan va dot bie'n).
2. Ne'u tru-dc do mot te bao nhiT vay da trai qua 3 Ian nguyen phan lien tiep va nhan diTdc cua moi trtfcfng noi bao 175000 nucleotit de tai ban cac gen noi tren. nhan diTdc cua moi trtfcfng noi bao 175000 nucleotit de tai ban cac gen noi tren. Trong cac te bao con thi tong so nucleotit eo trong 5 cap gen diTdc xet tren 2 cap
NST ay la bao nhieu? f k ;
Hudng dan
1. Thanh phan kieu gen cua cae giao tuf: AB DEf. AB deF. ab DEf. ab deF. AB DEf. AB deF. ab DEf. ab deF.
k2. Tong so'nucleotit C O trong 5 cap gen tren:
Goi X la tong so nucleotit eo trong 5 cap gen tren ta c6: ' ' ' '
x(2' - 1) = 175000 nucleotit => x = 25000 nucleotit
Bai 20: Trong dieu kien binh thiTdng, xet 2 cap gen, cap thuf nhat dai 5100A" c6
gen A chufa 20% Adenin, gen a chi?a so Itfdng tufng loai nucleotit bang nhau. Cap
thuf hai CO gen B chiJa 15% Guanin va tong sS'lien ke't hidro cua gen bkng 1725.
Gen b so' lu'dng tufng loai nucleotit bang nhau.
1. Tai viing sinh san cua o'ng dSn sinh due mot te bao sinh due chiJa cac gen noi tren nguyen phan lien tiep nhieu Ian cho 8 te' bao con 2n, moi tru'dng noi bao noi tren nguyen phan lien tiep nhieu Ian cho 8 te' bao con 2n, moi tru'dng noi bao da cung ca'p bao nhieu Ian nucleotit moi loai cho qua trinh tai ban cua cac gen do?
2. Cac te bao do giam phan cho cae loai giao tuf, so liTdng tufng loai nucleotit trong moi loai giao tuf bang bao nhieu? trong moi loai giao tuf bang bao nhieu?
Hiidngddn
1. So lu'dng moi loai nucleotit can cho qua trinh tai ban:
Cap gen thii 1:
5100 A "
So nucleotit cua gen x2 = 3000 nucleotit 3,4
+ Gen A eo: A = T = 3000 x 20% = 600 nucleotit ' „ :
G = X = 3000 X 30% = 900 nucleotit
300
Cgm nang ti/ On luygn thi Sinh hpc - Phiing Duy BS'ng
Cap gen thu" 2:
+ Gen B: Goi X la so'nucleotit cua gen B ta CO:
(2 X 15%x) + (3 X 15%x) = 1725 =>x = 1500 nucleotit
A = T = 1500 X 35% = 525 nucleotit
G = X = 1500 X 15% = 225 nucleotit.
+ Gen b: A = T - G = X = 1^=375 nucleotit.
4
So lifdng tij'ng loai nucleotit moi truTdng cung cap cho mot te bao chiJa cac gen noi tren nguyen phan hen tiep 3 Ian cho 8 te bao con.
A = T = (600 + 750 + 525 + 375) x (2' - 1) = 15750 nucleotit
G = X = (900 + 750 + 225 + 375) x (2' - 1) = 15750 nucleotit
2. So Itfcfng tiTng loai nucleotit cua m6i giao 11?:
2 cap gen di hdp giam phan cho 4 loai giao tu" AB, Ab, aB, ab - Giao tu" AB c6: A = T = 650 + 525 = 1125 nucleotit - Giao tu" AB c6: A = T = 650 + 525 = 1125 nucleotit
G = X - 900 + 225 = 1125 nucleotit