cong thuc sinh hoc 12 tham khao.pdf

7/29/2019 CONG THUC SINH HOC 12 THAM KHAO.pdf

1/40

1

CD SINH 12 LUYN THI IHC Trn Thin 0913.430 999 TRUNG TM TOAN OLYMPIC ISI

HE THONG TOAN BO KIEN THC SINH HOC PHOTHONG

*********************A.C S VAT CHAT VA C CHE DI TRUYEN CAP O PHAN T

(ADN ARN PROTEIN )

PHAN I . CAU TRUC ADN

I . Tnh so nucleotit cua ADN hoac cua gen1. oi vi moi mach cua gen :

- Trong ADN , 2 mach bo sung nhau , nen so nu va chieu dai cua 2 mach bang nhau .

A1 + T1 + G1 + X1 = T2 + A2 + X2 + G2 =2

N

- Trong cung mot mach , A va T cung nh G va X , khong lien ket bo sung nen khong nhathiet phai bang nhau . S bo sung ch co gia 2 mach : A cua mach nay bo sung vi T cua mkia , G cua mach nay bo sung vi X cua mach kia . V vay , so nu moi loai mach 1 bang sloai bo sung mach 2 .

A1 = T2 ; T1 = A2 ; G1 = X2 ; X1 = G22. oi vi ca 2 mach :

- So nu moi loai cua ADN la so nu loai o ca 2 mach :A = T = A1 + A2 = T1 + T2 = A1 + T1 = A2 + T2

G = X = G1 + G2 = X1 + X2 = G1 + X1 = G2 + X2Chu y :khi tnh t le %

%A = % T = 2

2%1% AA

2

2%1% TT = ..

%G = % X = 2

2%1% GG

2

2%1% XX =.

Ghi nh : Tong 2 loai nu khac nhom bo sung luon luon bang na so nu cua ADN hoac ban50% so nu cua ADN : Ngc lai neu biet :+ Tong 2 loai nu = N / 2 hoac bang 50% th 2 loai nu o phai khac nhom bo sung

+ Tong 2 loai nu khac N/ 2 hoac khac 50% th 2 loai nu o phai cung nhom bo sung3. Tong so nu cua ADN (N)Tong so nu cua ADN la tong so cua 4 loai nu A + T + G+ X . Nhng theo nguyen tac bo su(NTBS) A= T , G=X . V vay , tong so nu cua ADN c tnh la :

N = 2A + 2G = 2T + 2X hay N = 2( A+ G)

Do oA + G =2

N hoac %A + %G = 50%


2/40

2


4. Tnh so chu k xoan ( C )Mot chu k xoan gom 10 cap nu = 20 nu . khi biet tong so nu ( N) cua ADN :

N = C x 20 => C =20

N

5. Tnh khoi lng phan t ADN (M ) :Mot nu co khoi lng trung bnh la 300 vc . khi biet tong so nu suy ra

M = N x 300 vc6. Tnh chieu dai cua phan t ADN ( L ) :Phan t ADN la 1 chuoi gom 2 mach n chay song song va xoan eu an quanh 1 truc . vvay chieu dai cua ADN la chieu dai cua 1 mach va bang chieu dai truc cua no . Moi mac

2

N nucleotit, o dai cua 1 nu la 3,4 A0

L =2

N. 3,4A0

n v thng dung : 1 micromet = 10 4 angstron ( A0 ) 1 micromet = 103 nanomet ( nm) 1 mm = 103 micromet = 106 nm = 107 A0

II. Tnh so lien ket Hiro va lien ket Hoa Tr P1. So lien ket Hiro ( H )

+ A cua mach nay noi vi T mach kia bang 2 lien ket hiro+ G cua mach nay noi vi X mach kia bang 3 lien ket hiroVay so lien ket hiro cua gen la : H = 2A + 3 G hoac H = 2T + 3X

2. So lien ket hoa tr ( HT )a) So lien ket hoa tr noi cac nu tren 1 mach gen :

2

N- 1

Trong moi mach n cua gen , 2 nu noi vi nhau bang 1 lk hoa tr , 3 nu noi nhau

bang 2 lk hoa tr 2

N nu noi nhau bang2

N - 1

b) So lien ket hoa tr noi cac nu tren 2 mach gen : 2(2

N - 1 )

Do so lien ket hoa tr noi gia cac nu tren 2 mach cua ADN : 2(2

N - 1 )

c) So lien ket hoa tr ng photphat trong gen ( HT-P)

Ngoai cac lien ket hoa tr noi gia cac nu trong gen th trong moi nu co 1 lk hoa trgan thanh phan cua H3PO4 vao thanh phan ng . Do o so lien ket hoa tr Ptrong ca ADN la :

HT-P = 2(2

N - 1 ) + N = 2 (N 1)


3/40

3


PHAN II. C CHE T NHAN OI CUADN

I . TNH SO NUCLEOTIT T DO CAN DUNG1.Qua 1 lan t nhan oi ( t sao , tai sinh , tai ban )

+Khi ADN t nhan oi hoan toan 2 mach eu lien ket cac nu t do theo NTBS :AADN noi vi TT do va ngc lai ; GADN noi vi X T do va ngc lai . V vay so nu t

do moi loai can dung bang so nu ma loai no bo sungAtd=Ttd= A = T ; Gtd= Xtd= G = X

+ So nu t do can dung bang so nu cua ADNNtd= N

2. Qua nhieu t t nhan oi ( x t )+ Tnh so ADN con

- 1 ADN me qua 1 t t nhan oi tao 2 = 21 ADN con- 1 ADN me qua 2 t t nhan oi tao 4 = 22 ADN con- 1 ADN me qua3 t t nhan oi tao 8 = 23 ADN con- 1 ADN me qua x t t nhan oi tao 2x ADN con

Vay : Tong so ADN con = 2x

- Du t t nhan oi nao , trong so ADN con tao ra t 1 ADN ban au , vanco 2 ADN con ma moi ADN con nay co cha 1 mach cu cua ADN me . V vay soADN con con lai la co ca 2 mach cau thanh hoan toan t nu mi cua moi trng noi

bao .So ADN con co 2 mach eu mi = 2x 2

+ Tnh so nu t do can dung :- So nu t do can dung th ADN trai qua x t t nhan oi bang tong so nu sau

cung coup trong cac ADN con tr so nu ban au cua ADN me Tong so nu sau cung trong trong cac ADN con : N.2x So nu ban au cua ADN me :N

V vay tong so nu t do can dung cho 1 ADN qua x t t nhan oi :

Ntd= N .2x

N = N( 2X

-1)- So nu t do moi loai can dung la:

Atd= Ttd = A( 2X-1)

Gtd= Xtd = G( 2X-1)

+ Neu tnh so nu t do cua ADN con ma co 2 mach hoan toan mi :Ntd hoan toan mi = N( 2

X- 2)

Atd hoan toan mi = Ttd = A( 2X-2)


4/40

4


Gtd hoan toan mi = Xtd = G( 2X2)

II .TNH SO LIEN KET HIRO ; HOA TR - P C HNH THANH HOACB PHA V

1. Qua 1 t t nhan oia. Tnh so lien ket hirob pha v va so lien ket hiro c hnh

thanhKhi ADN t nhan oi hoan toan :- 2 mach ADN tach ra , cac lien ket hiro gia 2 mach eu b pha v nen so

lien ket hiro b pha v bang so lien ket hiro cua ADNH b t = HADN

- Moi mach ADN eu noi cac nu t do theo NTBS bang cac lien ket hiro nenso lien ket hiro c hnh thanh la tong so lien ket hiro cua 2 ADN con

H hnh thanh = 2 . HADNb. So lien ket hoa tr c hnh thanh :

Trong qua trnh t nhan oi cua ADN , lien ket hoa tr P noi cac nu trong moimach cua ADN khong b pha v . Nhng cac nu t do en bo sung th dc noi vinhau bang lien ket hoa tr e hnh thanh 2 mach mi

V vay so lien ket hoa tr c hnh thanh bang so lien ket hoa tr noi cac nu vinhau trong 2 mach cua ADN

HT c hnh thanh = 2 (2

N - 1 ) = N- 2

2 .Qua nhieu t t nhan oi ( x t )

a. Tnh tong so lien ket hidro b pha v va tong so lien kethidro hnh thanh :-Tong so lien ket hidro b pha v :

H b pha v = H (2x 1)

- Tong so lien ket hidro c hnh thanh :

H hnh thanh = H 2x

b. Tong so lien ket hoa tr c hnh thanh :Lien ket hoa tr c hnh thanh la nhng lien ket hoa tr noi cac nu t do lai

thanh chuoi mach polinucleotit miSo lien ket hoa tr noi cac nu trong moi mach n :

2

N- 1

- Trong tong so mach n cua cac ADN con con co 2 mach cu cua ADN mec gi lai

- Do o so mach mi trong cac ADN con la 2.2x - 2 , v vay tong so lien kethoa tr c hnh thanh la :


5/40

5


- HT hnh thanh = (2

N - 1) (2.2x 2) = (N-2) (2x 1)

III. TNH THI GIAN SAO MACo the quan niem s lien ket cac nu t do vao 2 mach cua ADN la ong thi ,khi mach nay tiep nhan va ong gop dc bao nhieu nu th mach kia cung lienket c bay nhieu nu

Toc o t sao : So nu dc tiep nhan va lien ket trong 1 giay1. Tnh thi gian t nhan oi (t sao )Thi gian e 2 mach cua ADN tiep nhan va kien ket nu t do

- Khi biet thi gian e tiep nhan va l ien ket trong 1 nu la dt , thi gian t saodc tnh la :

TG t sao = dt .2

N

- Khi biet toc o t sao (moi giay lien ket c bao nhieu nu )th thi gian tnhan oi cua ADN la :

TG t sao = N : toc o t sao


6/40

6


PHAN III . CAU TRUC ARN

I.TNH SO RIBONUCLEOTIT CUA ARN :- ARN thng gom 4 loai ribonu : A ,U , G , X va c tong hp t 1 mach ADNtheo NTBS . V va so ribonu cua ARN bang so nu 1 mach cua ADN

rN = rA + rU + rG + rX = 2N

- Trong ARN A va U cung nh G va X khong lien ket bo sung nen khong nhat thietphai bang nhau . S bo sung ch co gia A, U , G, X cua ARN lan lt vi T, A , X ,G cua mach goc ADN . V vay so ribonu moi loai cua ARN bang so nu bo sung mach goc ADN .

rA = T goc ; rU = A gocrG = X goc ; rX = Ggoc

* Chu y : Ngc lai , so lng va t le % tng loai nu cua ADN c tnh nh sau :

+ So lng : A = T = rA + rUG = X = rR + rX

+ T le % :

% A = %T =2

%% rUrA

%G = % X =2

%% rXrG

II. TNH KHOI LNG PHAN T ARN (MARN)Mot ribonu co khoi lng trung bnh la 300 vc , nen:

MARN = rN . 300vc =2N . 300 vc

III. TNH CHIEU DAI VA SO LIEN KET HOA TR P CUA ARN1 Tnh chieu dai :

- ARN gom co mach rN ribonu vi o dai 1 nu la 3,4 A0 . V vay chieu daiARN bang chieu dai ADN tong hp nen ARN o

- V vay LADN =LARN = rN . 3,4A0 =2

N. 3,4 A0

2 . Tnh so lien ket hoa tr P:

+ Trong chuoi mach ARN : 2 ribonu noi nhau bang 1 lien ket hoa tr , 3 ribonu noinhau bang 2 lien ket hoa tr Do o so lien ket hoa tr noi cac ribonu trong machARN la rN 1+ Trong moi ribonu co 1 lien ket hoa tr gan thanh phan axit H3PO4 vao thanh phanng . Do o so lien ket hoa tr loai nay co trong rN ribonu la rN

Vay so lien ket hoa tr P cua ARN:HTARN= rN 1 + rN = 2 .rN -1


7/40

7


PHAN IV . C CHE TONG HP ARN

I . TNH SO RIBONUCLEOTIT T DO CAN DUNG1 . Qua 1 lan sao ma :Khi tong hp ARN , ch mach goc cua ADN lam khuon mau lien cac ribonu t dotheo NTBS :

AADNnoi UARN ; TADNnoi A ARNGADNnoi XARN ; XADNnoi G ARN

V vay :+ So ribonu t do moi loai can dung bang so nu loai ma no bo sung tren mach goc

cua ADNrAtd= Tgoc; rUtd= AgocrGtd= Xgoc ; rXtd= Ggoc

+ So ribonu t do cac loai can dung bang so nu cua 1 mach ADNrNtd =

2

N

2. Qua nhieu lan sao ma ( k lan )Moi lan sao ma tao nen 1 phan t ARN nen so phan t ARN sinh ra t 1 gen

bang so lan sao ma cua gen o .So phan t ARN = So lan sao ma = K

+ So ribonu t do can dung la so ribonu cau thanh cac phan t ARN . V vay

qua K lan sao ma tao thanh cac phan t ARN th tong so ribonu t do can dung la:rNtd = K . rN

+ Suy luan tng t , so ribonu t do moi loai can dung la : rAtd = K. rA = K . Tgoc ; rUtd = K. rU = K . Agoc

rGtd = K. rG = K . Xgoc ; rXtd = K. rX = K . Ggoc* Chu y : Khi biet so ribonu t do can dung cua 1 loai :

+ Muon xac nh mach khuon mau va so lan sao ma th chia so ribonu o choso nu loai bo sung mach 1 va mach 2 cua ADN => So lan sao ma phai la c so

gia so ribbonu o va so nu loai bo sung mach khuon mau .+ Trong trng hp can c vao 1 loai ribonu t do can dung ma cha u xac

nh mach goc , can co so ribonu t do loai khac th so lan sao ma phai la c sochung gia so ribonu t do moi loai can dung vi so nu loai bo sung cua mach gocII. TNH SO LIEN KET HIRO VA LIEN KET HOA TR P :

1 . Qua 1 lan sao ma :a. So lien ket hidro :

H t = H ADN


8/40

8

CD SINH 12 LUYN THI IHC Trn Thin 0913.430 999 TRUNG TM TOAN OLYMPIC ISIH hnh thanh = H ADN

=>H t = H hnh thanh = HADN

b. So lien ket hoa tr :HT hnh thanh = rN 1

2. Qua nhieu lan sao ma ( K lan ) :a. Tong so lien ket hidro b pha v

H pha v = K . H

b. Tong so lien ket hoa tr hnh thanh :HT hnh thanh = K ( rN 1)

III. TNH THI GIAN SAO MA :* Toc o sao ma : So ribonu c tiep nhan va lien ket nhau trong 1 giay .*Thi gian sao ma :

- oi vi moi lan sao ma : la thi gian e mach goc cua gen tiep nhan va lienket cac ribonu t do thanh cac phan t ARN+ Khi biet thi gian e tiep nhan 1 ribonu la dt th thi gian sao ma la :

TG sao ma = dt . rN+ Khi biet toc o sao ma ( moi giay lien ket c bao nhieu ribonu ) th thi

gian sao ma la :TG sao ma = r N : toc o sao ma

- oi vi nhieu lan sao ma ( K lan ) :+ Neu thi gian chuyen tiep gia 2 lan sao ma ma khong ang ke thi thi

gian sao ma nhieu lan la :TG sao ma nhieu lan = K TG sao ma 1 lan

+ Neu TG chuyen tiep gia 2 lan sao ma lien tiep ang ke la t thi giansao ma nhieu lan la :

TG sao ma nhieu lan = K TG sao ma 1 lan + (K-1) t


9/40

9


PHAN IV . CAU TRUC PROTEINI . TNH SO BO BA MAT MA - SO AXIT AMIN

+ C 3 nu ke tiep nhau tren mach goc cua gen hp thanh 1 bo ba ma goc ,3 ribonu ke tiep cua mach ARN thong tin ( mARN) hp thanh 1 bo ba ma sao .V so ribonu cua mARN bang vi so nu cua mach goc , nen so bo ba ma goctrong gen bang so bo ba ma sao trong mARN .

So bo ba mat ma =3.2

N =3

rN

+ Trong mach goc cua gen cung nh trong so ma sao cua mARN thco 1 bo ba ma ket thuc khong ma hoa a amin . Cac bo ba con lai co ma hoa a.amin

So bo ba co ma hoa a amin (a.amin chuoi polipeptit)=3.2

N - 1 =3

rN - 1

+ Ngoai ma ket thuc khong ma hoa a amin , ma m au tuy coma hoa a amin , nhng a amin nay b cat bo khong tham gia vao cau truc protein

So a amin cua phan t protein (a.amin pro hoan chnh )= 3.2N

- 2 = 3rN

- 2II. TNH SO LIEN KET PEPTIT

- So lien ket peptit hnh thanh = so phan t H2O tao ra- Hai a amin noi nhau bang 1 lien ket peptit , 3 a amin co 2 lien ket peptit

..chuoi polipeptit co m la a amin th so lien ket peptit la :So lien ket peptit = m -1

III. TNH SO CACH MA HOA CUA ARN VA SO CACH SAP AT A AMINTRONG CHUOI POLIPEPTITCac loai a amin va cac bo ba ma hoa: Co 20 loai a amin thng gap trong cac phant protein nh sau :1) Glixerin : Gly 2) Alanin : Ala 3) Valin : Val 4 )Lxin : Leu5) Izolxin : Ile 6 ) Xerin : Ser 7 ) Treonin : Thr 8 ) Xistein :Cys

9) Metionin : Met 10) A. aspartic : Asp 11)Asparagin : Asn 12) A glutamic :Glu13) Glutamin :Gln 14) Arginin : Arg 15) Lizin : Lys 16)Phenilalanin :Phe17) Tirozin: Tyr 18) Histidin : His 19) Triptofan : Trp 20) Prolin : pro

Bang bo ba mat ma


10/40

10


U X A G

U

U U UU U X pheU U A

U U G Leu

U X UU X XU X A Ser

U X G

U A U TyrU A XU A A **

U A G **

U G UU G X CysU G A **

U G GTrp

UXA

G

X

X U UX U X

LeuX U AX U G

X X UX X XProX X AX X G

X A U HisX A XX A AX A G Gln

X G UX G XX G AArgX G G

UXAG

A

A U AA U X HeA U AA U G *Met

A X UA X XThrA X AA X G

A A UAsnA A XA A AA A GLys

A G UA G XSerA G AA G GArg

UXAG

G

G U UG U X

ValG U AG U G * Val

G X UG X X

G X AAlaG X G

G A UG A X

AspG A AG A GGlu

G G UG G X

G G A GliG G G

U

XAG

K hieu : * ma m au ; ** ma ket thuc


11/40

11


PHAN V . C CHE TONG HP PROTEIN

I .TNH SO AXIT AMIN T DO CAN DUNG :Trong qua tnh giai ma , tong hp protein, ch bo ba nao cua mARN co ma hoa aamin th mi c ARN mang a amin en giai ma .

1 ) Giai ma tao thanh 1 phan t protein: Khi riboxom chuyen dch t au nay en au no cua mARN e hnh thanh

chuoi polipeptit th so a amin t do can dung c ARN van chuyen mang enla e giai ma m au va cac ma ke tiep , ma cuoi cung khong c giai . Vvay so a amin t do can dungh cho moi lan tong hp chuoi polipeptit la :

So a amin t do can dung : So aatd =3.2

N - 1 =3

rN - 1

Khi ri khoi riboxom , trong chuoi polipeptit khong con a amin tng ng vima m au .Do o , so a amin t do can dung e cau thanh phan t protein (tham gia vao cau truc protein e thc hien chc nang sinh hoc ) la :So a amin t do can dung e cau thanh protein hoan chnh :

So aap =3.2

N - 2 =3

rN - 2

2 ) Giai ma tao thanh nhieu phan t protein :

Trong qua trnh giai ma , tong hp protein , moi lt chuyen dch cua riboxomtren mARN se tao thanh 1 chuoi polipeptit .

- Co n riboxomchuyen dch qua mARN va khong tr lai la co n lt trt cuariboxom . Do o so phan t protein ( gom 1 chuoi polipeptit ) = so lt trtcua riboxom .

- Mot gen sao ma nhieu lan, tao nhieu phan t mARN cung loai . Moi mARNeu co n lt riboxom trt qua th qua trnh gia ma bi K phan t mARN setao ra so phan t protein :

so P = tong so lt trt RB = K .n

Tong so axit amin t do thu c hay huy ong va e tham gia vao cau truccac phan t protein va e tham gia ma m au. V vay :

-Tong so axit amin t do c dung cho qua trnh giai ma la so axitamin tham gia vao cau truc phan t protein va so axit amin thjam gia vaoviec giai ma m au (c dung 1 lan m ma thoi ).


12/40

12


aatd = So P . (3

rN - 1) = Kn (3

rN - 1)

- Tong so a amin tham gia cau truc protein e thc hien chc nang sinhhoc ( khong ke a amin m au ) :

aaP = So P . (

3

rN - 2 )

II . TNH SO PHAN T NC VA SO LIEN KET PEPTIT

Trong qua trnh giai makhi chuoi polipeptit ang hnh thanh th c 2 axit amin ketiep noi nhau bang lien ket peptit th ong thi giai phong 1 phan t nc, 3 axitamin noi nhau bang 2 lien ket paptit, ong thi giai phong 2 phan t nc Vvay : So phan t nc c giai phong trong qua trnh giai matao 1 chuoi polipeptit

laSo phan t H2O giai phong =

3

rN - 2

Tong so phan t nc c giai phong trong qua trnh tong hp nhieu phan tprotein (moi phan t protein la 1 chuoi polipeptit ) .

H2O giai phong = so phan t protein .3

rN - 2

Khi chuoi polipeptit ri khoi riboxom tham gia chc nang sinh hoc th axitamin m au tach ra 1 moi lien ket peptit vi axit amin o khong con so

lien ket peptit thc s tao lap c la 3rN -3 = so aaP -1 . v vay tong so lien

ket peptit thc s hnh thanh trong cac phan t protein la :

peptit = Tong so phan t protein . (3

rN - 3 ) = So P(so aaP - 1 )

III. TNH SO ARN VAN CHUYEN ( tARN)Trong qua trnh tong hp protein, tARN nang axit amin en giai ma. Moi lt giaina, tARN cung cap 1 axit amin mot phan t ARN giai ma bao nhieu lt th cungcap bay nhieu axit amin .

S giai ma cua tARN co the khong giong nhau : co loai giai ma 3 lan, co loai 2 lan,1 lan .

- Neu co x phan t giai ma 3 lan so aado chung cung cap la 3x.y phan t giai ma 2 lan la 2 y .z phan t giai ma 1 lan la z

-Vay tong so axit amin can dung la do cac phan t tARN van chuyen 3 loai o cungcap phng trnh.


13/40

13


3x + 2y + z = aa t do can dung

IV. S DCH CHUYEN CUA RIBOXOM TREN ARN THONG TIN

1.Van toc trt cua riboxom tren mARN

- La o dai mARN ma riboxom chuyen dch c tron 1 giay.- Co the tnh van toc trt bang cach cia chieu dai mARN cho thi gianriboxom trt t au no en au kia. (trt het Marn )

v =t

l (A0/s )

* Toc o giai ma cua RB :- La so axit amin cua chuoi polipeptit keo dai trong 1 giay (so bo ba c

giai trong 1 giay ) = So bo ba ma RB trt trong 1 giay .

- Co the tnh bang cach chia so bo ba cua mARN cho thi gian RB trthet mARN.

Toc o giai ma = so bo cua mARN : t2. Thi gian tong hp 1 phan t protein (phan t protein gom 1 chuoi

polipeptit )- Khi riboxom trt qua ma ket thuc, ri khoi mARN th s tong hp phan t

protein cua riboxom o c xem la hoan tat. V vay thi gian hnh thanh 1 phan t

protein cung la thi gian riboxom trt het chieu dai mARN ( t au noen au kia ).

t =t

l

3. Thi gian moi riboxom trt qua het mARN ( ke t luc riboxom 1 batau trt )Goi t : khoang thi gian riboxom sau trt cham hn riboxom trc

- oi vi RB 1 : t- oi vi RB 2 : t + t- oi vi RB 3 : t + 2t- Tng t oi vi cac RB con lai

VI. TNH SO A AMIN T DO CAN DUNG OI VI CAC RIBOXOM CONTIEP XUC VI mARNTong so a amin t do can dung oi vi cac riboxom co tiep xuc vi 1 mARN la tongcua cac day polipepti ma moi riboxom o giai ma c :

aatd = a1 + a2 + + ax


14/40

14


Trong o : x = so riboxom ; a1 , a2 = so a amin cua chuoi polipeptit cua RB1 ,RB2 .* Neu trong cac riboxom cach eu nhau th so a amin trong chuoi polipeptit cuamoi riboxom o lan lt hn nhau la 1 hang so : so a amin cua tng riboxom hopthanh 1 day cap so cong :

- So hang au a1 = so 1 a amin cua RB1

- Cong sai d = so a amin RB sau kem hn so a amin trc o .- So hang cua day x = so riboxom co tiep xuc mARN ( ang trt tren

mARN )Tong so a amin t do can dung la tong cua day cap so cong o:

Sx =2

x 2a1 + (x 1 ) d

B .C S VAT CHAT VA C CHE DI TRUYEN CAP O TE BAO (NST)

PHAN I . NHIEM SAC THE VA C CHE NGUYEN PHAN

I. TNH SO TE BAO CON TAO THANHTe bao sinh san bang cach phan oi tr thanh 2 te bao con so te bao thehe saugap oi so te bao the he trc

T 1 te bao ban au :+ Qua 1 t phan bao tao 21 te bao con

+ Qua 2 t phan bao tao 2

2

te bao con=> So te bao con tao thanh t 1 te bao ban au qua x t phan bao A= 2x

T nhieu te bao ban au : + a1 te bao qua x1 t phan bao te bao con a1.2x1

+ a2 te bao qua x2 t phan bao te bao con a2.2x2=> Tong so te bao con sinh ra A = a1 .2

x1 + a2 . 2x2 + ..

II . TNH SO NHIEM SAC THE TNG NG VI NGUYEN LIEU CCUNG CAP TRONG QUA TRNH T NHAN OI CUA NHIEM SAC THE

Khi t nhan oi, moi na cua nhiem sac the ban au tao them na mi t nguyenlieu cua moi trng noi bao e tr thanh 2 nhiem sac the giong het no. (Do o cothe quan niem la mot nhiem sac the cu tao them mot nhiem sac the mi ).

Moi t nguyen phan co 1 dt t nhan oi cua cac nhiem sac thetrong tebao me so t t nhan oi cua nhiem sac the = so ot nguyen phan cua te bao .

So NST tng ng vi nguyen lieu c moi trng noi bao cung capbang tong so NST sau cung trong tat ca te bao con tr so NST ban au te baome


15/40

15


- Tong so NST sau cung trong tat ca te bao con : 2n .2x- So NST ban au trong te bao me : 2nVay tong so NST tng ng vi nguyen lieu c cung cap khi 1 te bao 2n

phai qua x t nguyen phan la :NST = 2n . 2

x - 2n = 2n (2x 1)

So NST cha hoan toan nguyen lieu miDu t nguyen phan nao , trong so NST cua te bao con cung co 2 NST mang1/2 NST cu cua 1 NST ban au so NST co cha 1/ 2 NST cu = 2 lan so NSTban au . V vay , so NST trong te bao con ma moi NST nay eu c cau thanht nguyen lieu mi do moi trng noi bao cung cap la :

NST mi = 2n . 2x - 2. 2n = 2n (2x 2 )

III. TNH THI GIAN NGUYEN PHAN1. Thi gian cua 1 chu k nguyen phan :La thi gian cua 5 giai oan , co the c tnh t au k trc en het k trunggian hoac t au k trung gian en het k cuoi2. Thi gian qua cac t nguyen phan

La tong thi gian cua cac t nguyen phan lien tiep Toc o nguyen phan khong thay oi :

Khi thi gian cua t nguyen phan sau luon luon bang thi gian cua tnguyen phan trc .

TG = thi gian moi t x so t nguyen phan

Toc o nguyen phan thay oiNhanh dan eu : khi thi gian cua t phan bao sau t hn thi gian cua t phanbao trc la 1 hang so ( ngc lai , thi gian cua nguyen phan giam dan eu )

V du :Thi gian cua t nguyen phan 1 : 30 phut 30 phutThi gian cua t nguyen phan 2 : 28 phut 32 phutThi gian cua t nguyen phan 3 : 36 phut 34 phut

Nhanh dan eucham dan eu

Vay : Thi gian qua cac t phan bao lien tiep la tong cua day cap so cong mamoi so hang la thi gian cua 1 t nguyen phan

TG =2

x ( a1 + ax ) =2

x [ 2a1 + ( x 1 ) d ]


16/40

16


PHAN 2 . C CHE GIAM PHAN VA THU TINH

I. TNH SO GIAO T HNH THANH VA SO HP T TAO RA1.Tao giao t ( Kieu NST gii tnh : c XY ; cai XX)

vung chn , moi te bao sinh duc s khai ( te bao sinh tinh ) qua giamphan cho 4 tinh trung va gom 2 loai X va Y co t le bang nhau .

- So tinh trung hnh thanh = So te bao sinh tinh x 4- So tinh trung X hnh thanh = So te bao Y hnh thanh

vung chn , moi te bao sinh duc s khai ( te bao sinh trng ) quagiam phan ch cho 1 te bao trng gom 1 loai X , 3 te bao kia la the nhhng ( ve sau b tieu bien )- So trng hnh thanh = So te bao trng x 1- So the nh hng = So te bao sinh trng x 3

2 .Tao hp t Mot tinh trung loai X ket hp vi trng tao thanh 1 hp t XX, con tinh

trung loai Y ket hp vi trng tao thanh 1 hp t XY

- Tinh trung X x Trng X Hp t XX ( cai )- Tinh trung Y x Trng X Hp t XY (c )

Moi te bao trng ch ket hp vi mot tinh trung e tao thanh 1 hp t .So hp t tao thanh = So tinh trung thu tinh = So trng thu tinh

3 T le thu tinh ( hieu suat thu tinh ) : T le thu tinh cua tinh trung = So tinh trung thu tinh : Tong so tinhtrng hnh thanh

T le thu tinh cua trng = So trng thu tinh : Tong so trng hnhthanh

III. TNH SO LOAI GIAO T VA HP T KHAC NHAU VE NGUON GOCVA CAU TRUC NST

1. S phan li va to hp cua NST trong qua trnh giam phana) phan bao I :- T k sau en k cuoi , moi NST kep trong cap tng ong phan li ve 1te bao , co kha nang tong hp t do vi cac NST kep cua cac cap khactheo nhieu kieu .- Neu co trao oi oan trong cap NST th ch thay oi dang trong sokieu o , ch khong lam tang so kieu to hp+ So kieu to hp : 2n ( n so cap NST tng ong )


17/40

17


+ Cac dang to hp : dung s do phan nhanh hoac cach nhan ai sob) phan bao II- T k sau en k cuoi , moi NST n trong NST kep phan li ve 1 giaot va co kha nang to hp t do vi cac NST n cua nhng cap khac taothanh nhieu kieu to hp , do o phat sinh nhieu loai giao t- Neu co trao oi oan xay ra tai 1 iem trong cap NST th c moi capco trao oi oan se lam so loai giao t tang gap oi+ So kieu giao t : 2 n + m ( m : so cap NST co trao oi oan )+ Dang to hp : dung s o phan nhanh hoac cach nhan ai so


18/40

18


C . CAC QUY LUAT DI TRUYENPHAN I . CAC NH LUAT CUA MENDEN

A. TOM TAT L THUYETI .MOT SO KHAI NIEM VA THUAT NG

1. Alen : la cac trang thai khac nhau cua cung mot gen . Cac alen co v tr

tng ng tren 1 cap NST tng ong (locut) . VD: gen quy nh mau hat co 2 alen: A -> hat vang ; a -> hat xanh .2. Cap alen : la 2 alen giong nhau hay khac nhau thuoc cung mot gen

nam tren 1 cap NST tng ong v tr tng ng trong te bao lng boi . DV :AA , Aa , aa

- Neu 2 alen co cau truc giong nhau -> Cap gen ong hp . VD : AA, aa- Neu 2 alen co cau truc khac nhau -> Cap gen d hp . VD di5Aa , Bb3 .The ong hp : la ca the mang 2 alen giong nhau thuoc cung 1 gen .

VD : aa , AA , BB, bb4 The d hp : la ca the mang 2 alen khac nhau thuoc cung 1 gen .VD : Aa , Bb , AaBb

5 . Tnh trang tng phan : la 2 trang thai khac nhau cua cung mot tnhtrang nhng bieu hien trai ngc nhau

VD : than cao va than thap la 2 trang thai cua tnh trang chieucao than , thanh cap tnh trang tng phan

6 . Kieu gen : la to hp toan bo cac gen trong te bao cua c the sinh

vat VD : Aa , Bb ,Ab

AB,bv

BV,bV

Bv

7 . Kieu hnh : La to hp toan bo cac tnh trang va ac tnh c theVd : ruoi dam co kieu hnh than xam canh dai hoac than en

canh nganII CAC NH LUAT CUA MEN DEN

A. PHNG PHAP NGHIEN CU DI TRUYEN CUA MENDEN : co 2phng phap

1 . Phng phap phan tch c the lai :a. Chon dong thuan : trong rieng va e t thu phan , neu i con hoan

toan giong bo me th th au o thuan chung ve tnh trang nghien cu .b. Lai cac cap bo me thuan chung khac nhau ve mot hoac vai cap

tnh trang tng phan . VD : Pt/c : vang x xanhc . S dung thong ke toan hoc tren so lng ln ca the lai e phan

tch quy luat di truyen t P -> F


19/40

19


2. Lai phan tch : la phep lai gia c the mang tnh trang troi vi c themang tnh trang lan e kiem tra kieu gen cua ca the mang tnh trang troi la onghp hay d hp

- Neu the he lai sinh ra ong tnh th c the co kieu hnh troi co kieu genong hp

- Neu the he lai sinh ra phan tnh th c the co kieu hnh troi co kieu gen

d hpVD : Lai phan tch au hat vang (co KG AA hoac Aa ) vi au hat xanh

(KG : aa )+ Neu Fa ong tnh hat vang th cay au hat vang muon tm KG co

KG ong hp troi (AA )+ Neu Fa phan tnh ( 1 vang : 1 xanh ) th cay au hat vang muon tm

KG co KG d hp troi (Aa )B . LAI MOT CAP TNH TRANG

1 . Khai niem : phep lai trong o cap bo me thuan chung khac nhau ve 1cap tnh trang tng phan em lai

2 .Th nghiem : Lai 2 th au Ha Lan thuan chung khac nhau ve 1 cap tnh trang tng phan la hat vang vi hat luc , thu c F1 ong loat hat vang . Cho F1t thu , F2 thu c hat vang ; hat xanh

3. Noi dung nh luat :a. nh luat ong tnh : Khi lai bo me khac nhau ve 1 cap tnh trang

tng phan , th F1 co kieu hnh ong nhat bieu hien tnh trang 1 ben cua bo hoacme . Tnh trang bieu hien F1 la tnh trang troi , tnh trang khong bieu hien F1 latnh trang lan

b. nh luat phan tnh : Khi cho cac c the lai F1 t thu phan hoac giaophan th F2 co s phan li kieu hnh theo t le xap x 3 troi : 1 lan

4 . Giai thch nh luat :a. Theo Menden : the he lai F1 khong sinh giao t lai ma ch sinh ra

giao t thuan khiet

b. Theo thuyet NST ( c s te bao hoc cua nh luat ong tnh va phantnh )5 . ieu kien nghiem ung cua nh luat ong tnh va phan tnh :

- Bo me phai thuan chung va khac nhau 1 cap tnh trang tng phanem lai

- Tnh trang troi phai troi hoan toan- So ca the phan tch phai ln

6. Y ngha :


20/40

20


- nh luat ong tnh : lai cac giong thuan chung tao u the lai F 1 docac cap gen d hp quy nh .

-nh luat phan tnh : khong dung F1 lam giong v F2 xuat hien tnhtrang lan khong co li

- ng dung nh luat ong tnh va phan tnh trong phep lai phan tch :cho phep lai xac nh c kieu gen cua c the mang tnh trang troi la the ong hphay d hp

C . LAI HAI VA NHIEU CAP TNH TRANG1. Khai niem : La phep lai trong o cap bo me thuan chung em lai phan

biet nhau ve 2 hay nhieu cap tnh trang tng phan . VD : Lai gia au Ha Lan hatvang, trn vi hat xanh, nhan

2 Th nghiem cua Mendena. th nghiem va ket qua :- Lai gia 2 th au thuan chung khac nhau 2 cap tnh trang tng phan

: hat vang vo trn vi hat xanh vo nhan , thu c F1 ong loat hat vang trn .- Cho cac cay F1 vang trn t thu phan hoac giao phan vi nhau , F2 thu

c t le xap x : 9 vang , trn ; 3 vang ,nhan ; 3 xanh trn ; 1 xanh , nhan .b. Nhan xet :

- F2 xuat hien 2 loai kieu hnh mi khac bo me la vang nhan va xanhtrn c goi la bien d to hp

- Moi tnh trang xet rieng tuan theo nh luat ong tnh F1 va phantnh F2

+ Xet rieng :* F1 :100% hat vang F2 :hat vang / hat xanh = 9+ 3

/3+1 = 3 / 1* F1 : 100% hat trn F2 : hat trn / hat nhan = 9+3 / 3+1

= 3 /1+ Xet chung 2 tnh trang :

F2 = (3V :1X) ( 3T : 1N) = ( 9 V-T : 3V N : 3 X-T : 1X-N )

Vay moi cap tnh trang di truyen khong phu thuoc vao nhau3. Noi dung nh luat phan li oc lap : Khi lai 2 bo me thuan chung,khac nhau ve 2 hay nhieu cap tnh trang tng phan th s di truyen cua cap tnhtrang nay khong phu thuoc vao s di truyen cua cap tnh trang kia ,do o F2 xuat

hien nhng to hp tnh trang khac bo me goi la bien d to hp4 . Giai thch nh luat phan li oc lap cua Menden theo thuyet NST (

c s TB hoc )


21/40

21

CD SINH 12 LUYN THI IHC Trn Thin 0913.430 999 TRUNG TM TOAN OLYMPIC ISI-Gen troi A : hat vang ; gen lan a : hat xanh . Gen troi B : hat trn ; gen

lan b : hat nhan- Moi cap gen qui nh 1 cap tnh trang va nam tren 1 cap NST tng ong

rieng- P t/c : vang trn x xanh nhan F1 : 100% vang trn . F1 x F1 -> F 2 gom

:

+ 9 kieu gen : 1AABB: 2 AaBB : 2 AABb : 4 AaBb : 1AAbb : 2 Aabb:1aaBB :2aaBb: 1aabb.

+ 4 kieu hnh : 9 vang trn : 3 vang nhan : 3 xanh trn : 1 xanh nhan5 . ieu kien nghiem ung :

- Bo me phai thuan chung va khac nhau ve cac cap tnh trang tngphan em lai

- Tnh trang troi phai troi hoan toan .- So ca the phan tch phai ln .

- Cac cap gen xac nh cac cap tnh trang tng phan nam tren cac capNST tng ong khac nhau .- Cac cap gen phai tac ong rieng re len s hnh thanh tnh trang

6 . Y ngha : : S phan li oc lap va to hp t do cua NST va gen tronggiam phan , thu tinh lam tang bien d to hp la nguon nguyen lieu cho chon giong vatien hoa , giai thch s a dang cua sinh vat

D. DI TRUYEN TNH TRANG TRUNG GIAN ( troi khong hoan toan )1 . Th nghiem : Lai 2 th hoa Da Lan thuan chung : hoa do : AA vi hoa

trang aa , c cac cay F1 eu co hoa mau hong (Aa) . Cho cac cay F1 t thu phan( hoac giao phan ) , F2 phan li theo t le : 1 o : 2 hong : 1 trang* Nhan xet : The ong hp va d hp co kieu hnh khac nhau2 . Noi dung nh luat : Khi lai 2 c the bo me khac nhau ve 1 cap tnh

trang, ,th F1 ong loat mang tnh trang trung gian gi bo va me .3 . Giai thch :

- Tnh trang mau hoa do mot cap gen quy nh , AA : hoa o ; aa : hoatrang ; Aa : hoa hong .

- S o lai : P : AA ( hoa o ) x aa ( hoa trang )Gp : A aF1 : Aa ( 100% hoa hong )F1 x F1 : Aa (hoa hong ) x Aa (hoa hong )GF1 : A , a A , aF 2 : AA ( 1 o ) : 2 Aa (2 hong ) :

aa ( 1 trang )


22/40

22


B. PHNG PHAP GIAII . TNH SO LOAI VA THANH PHAN GEN GIAO T

1. So loai giao t :Khong tuy thuoc vao kieu gen trong KG ma tuy thuoc vao so cap gen d hp trong

o :+ Trong KG co 1 cap gen d hp 21 loai giao t+ Trong KG co 2 cap gen d hp 22 loai giao t

+ Trong KG co 3 cap gen d hp 23 loai giao t+ Trong KG co n cap gen d hp 2n loai giao t

2 . Thanh phan gen (KG) cua giao t :Trong te bao (2n) cua c the gen ton tai thanh tng cap tng ong , con trong

giao t (n) ch con mang 1 gen trong cap

+ oi vi cap gen ong hp AA ( hoac aa) : cho 1 loai giao t A ( hoac1 loai giao t a )

+ oi vi cap gen d hp Aa:cho 2 loai giao t vi t le bang nhau giaot A va giao t a

+ Suy luan tng t oi vi nhieu cap gen d hp name tren cac cap NSTkhac nhau , thanh phan kieu gen cua cac loai giao t c ghi theo s o phannhanh ( s o Auerbac ) hoac bang cach nhan ai so

V du : Kieu gen :AaBbDd giao t : ABD, ABd , AbD, AbdaBD, aBd , abD , abd

II . TNH SO KIEU TO HP , KIEU GEN , KIEU HNH VA CAC T LE PHAN

LI I CON1. So kieu to hp :Moi loai giao t c to hp t do vi cac loai giao t cai tao thanh nhieu kieuto hp trong cac hp t . V vay so kieu to hp gia cac loai giao t c vacai la :

So kieu to hp = so loai giao t c x so loai giao t caiChu y :

+ Biet kieu to hp => biet so loai giao t c , giao t cai => bietc cap gen d hp trong kieu gen cua cha me

+ Kieu to hp khac nhau nhng co the a en kieu gen giongnhau => so KG < so kieu to hp .

2. So loai giao t va t le phan li ve kieu gen(KG) , kieu hnh (KH):S di truyen cua cac gen la oc lap vi nhau => s to hp t do gia cac capgen cung nh gia cac cap tnh trang .V vay , ket qua ve kieu gen cung nhve kieu hnh i con c tnh nh sau :


23/40

23

CD SINH 12 LUYN THI IHC Trn Thin 0913.430 999 TRUNG TM TOAN OLYMPIC ISI+ T le KG chung cua nhieu cap gen = cac t le KG rieng re cua

moi cap gen nhan vi nhau=> So KG tnh chung = so KG rieng cua moi cap gen nhan vi nhau

+ T le KH chung cua nhieu cap tnh trang = cac t le KH riengre cua moi cap tnh trang nhan vi nhau

III. TM KIEU GEN CUA BO ME1. Kieu gen rieng cua tng loai tnh trang :

Xet rieng ket qua i con lai F1 cua tng loai tnh tranga) F1 ong tnh :

+ Neu bo me (P) co KH khac nhau th F1 nghiem ung L ongtnh cua Menden => tnh trang bieu hien F1 la tnh trang troi va the he Peu thuan chung : AA x aa .

+ Neu P cung kieu hnh va F1 mang tnh trang troi th 1 trong 2Pco KG ong hp troi AA, P con lai co the la AA hoac Aa

+ Neu P khong ro KH va F1 mang tnh trang troi , th 1 trong 2 Pla ong hp troi AA ,P con lai tuy y : AA , Aa hoac aa .b) F1 phan tnh neu co t le :

F1 phan tnh theo t le 3:1F1 nghiem ung nh luat phan tnh cua Menden => tnh trang

4

3 la tnh

trang troi ,4

1 la tnh trang lan va P eu d hp Aa xAa

Chu y : Trong trpng hp troi khong hoan toan th t le F1 la 1:2: 1 . Trong trng

hp co gen gay cheat trang thai ong hp th t le F1 la 2:1 . F1 phan tnh theo t le 1 :1F1 la ket qua ac trng cua phep lai phan tch the d hp => 1ben P coKG d hp Aa , P con lai ong hp aa F1 phan tnh khong ro t leDa vao ca the mang tnh trang lan F1 la aa => P eu cha gen lan a ,phoi hp vi KH cua P suy ra KG cua P

2. Kieu gen chung cua nhieu loai tnh tranga) Trong phep lai khong phai la phep lai phan tch.Ket hp ket qua ve KG rieng cua tng loai tnh trang vi nhau .V du : ca chua A : qua o ; a qua vang

B : qua tron ; b qua bau ducCho lai 2 cay cha ro KG va KH vi nhau thu c F1 gom : 3 cay o tron ;3 obau duc ;1 vang tron ; 1 vang bau duc . Cac cap gen nam tren cac cap NSTkhac nhau .Tm KG 2 cay thuoc the he P- Xet rieng tng cap tnh trang :


24/40

24

CD SINH 12 LUYN THI IHC Trn Thin 0913.430 999 TRUNG TM TOAN OLYMPIC ISI+ F1gom (3+3) o : ( 1 + 1) vang = 3 o : 1 vang ( theo L ong tnh )=>P : Aa x Aa+ F1gom (3 +1 ) tron : (3 + 1 ) bau duc = 1 tron : 1 bau duc ( lai phan tch dhp ) => P : Bb x bb

- Xet chung : Ket hp ket qua ve KG rieng cua moi loai tnh trang tren =>KG cua P la : AaBb x AaBb .

b) Trong phep lai phan tch .Khong xet rieng tng loai tnh trang ma phai da vao ket qua cua phep lai e

xac nh t le va thanh phan gen cua moi loai giao t sinh ra => KG cua ca the oIV CACH NHAN NH QUY LUAT DI TRUYEN1 ) Can c vao phep lai khong phai la phep lai phan tch :

- Tm t le phan tnh ve KH the he con oi vi moi loai tnh trang- Nhan t le KH rieng re cua loai tnh trang nay vi vi t le KH rieng cua loai

tnh trang kia . Neu thay ket qua tnh c phu hp vi ket qua phep lai => 2 cap

gen quy nh 2 loai tnh trang o nam tren 2 cap NST khac nhau , di truyen theo quyluat phan li oc lap cua Menden ( tr t le 1:1 nhan vi nhau )

V du : Cho lai 2 th ca chua : qua o than cao vi qua o than thap thu c37,5% qua o than cao : 37,5% qua o than thap :12,5% qua vang than cao , 12,5%qua vang than thap . Biet rang moi tnh trang do 1 gen quy nh

Giai+ Xet rieng tng tnh trang the he con

-( 37,5% + 37,5% ) o : ( 12,5% + 12,5% ) vang = 3 o : 1 vang-( 37,5% + 12,5% ) cao : ( 37,5 % + 12,5% ) thap = 1 cao : 1 thap+ Nhan 2 t le nay ( 3 o : 1 vang ) ( 1 cao : 1 thap ) = 3 o cao : 3 o thap : 1 vang

cao : 1 vang thap . phu hp vi phep lai trong e bai . Vay 2 cap gen quy nh 2cap nam tren 2 cap NST khac nhau2) Can c vao phep lai phan tch :Khong xet rieng tng loai tnh trang ma da vao ket qua phep lai e xac nh t leva loai giao t sinh ra cua cac ca the can tm .

Neu ket qua lai chng to ca the d hp kep cho ra 4 loai giao t t le bang nhau=> 2cap gen o nam tren 2 cap NST khac nhau .


25/40

25


PHAN II LIEN KET GEN - HOAN V GENA . TOM TAT L THUYET

I . LIEN KET GEN HOAN TOAN :1. Th nghiem cua Mocgan :

a. oi tng nghien cu : Ruoi giam co nhng iem thuan li trong nghiencu di truyen : de nuoi trong ong nghiem , e nhieu , vong i ngan ( 10 -14 ngay /the he ) , so lng NST t (2n = 8 ) , nhieu bien d de thay .

b. Noi dung th nghiem :- Lai 2 dong ruoi giam thuan chung khac nhau ve 2 cap tnh trang tng phan

la ruoi than xam , canh dai vi ruoi than en canh ngan . c F1 ong loat ruoithan xam canh dai .

Vay , theo nh luat ong tnh cua Menden : than xam canh dai la tnh trangtroi hoan toan so vi than en ., canh ngan va F1 co kieu gen d hp 2 cap gen .

- Lai phan tch ruoi c F1 than xam , canh dai vi ruoi cai than en , canhngan . F2 thu c 50% than xam canh dai ; 50% than en canh ngan

c. Nhan xet :- Neu 2 tnh trang do 2 cap gen nam tren 2 cap NST khac nhau di truyen phan

li oc lap th ket qua lai phan tch thu c 4 loai kieu hnh vi t le bang nhau .- Ket qua th nghiem ch thu c 2 loai kieu hnh giong bo me . Ruoi

cai la the ong hp ve 2 cap gen lan ch cho 1 loai giao t , chng to ruoi cai F1 dhp 2 cap gen nhng ch cho2 loai giao t vi t le bang nhau ch khong phai la 4 loai giao t giong nh phan li

oc lap cua MendenNh vay , co s di truyen lien ket gia 2 tnh trang mau sac than va hnh

dang canh . Tnh trang than xam luon i kem vi tnh trang canh dai ; tnh trangthan en luon i kem vi tnh trang canh ngan .

2 . Giai thch c s te bao hoc ( ve s o phan li NST)- Quy c : B : than xam , b : than en ; V canh dai , v : canh ngan- Ket qua th nghiem tren ch co the giai thch c neu tha nhan cac gen B

va V cung nam tren 1 NST ( k hieu BV ) , cac gen b va v cung nam tren 1 NST (

k hieu bv ) trong cap tng ong .- S o lai : (HS t viet )3 . Noi dung nh luat lien ket gen hoan toan :

- Cac gen phan bo tren NST tai nhng v tr xac nh goi la locut .- Trong te bao , so lng gen ln hn so lng NST nhieu nen tren moi NST

phai mang nhieu gen .- Cac gen nam tren 1 NST phan li cung nhau trong qua trnh phan bao va lam

thanh 1 nhom gen len ket


26/40

26

CD SINH 12 LUYN THI IHC Trn Thin 0913.430 999 TRUNG TM TOAN OLYMPIC ISI- So nhom gen lien ket moi loai la tng ng vi so NST n boi (n) cua

loai o .- So nhom tnh trang di truyen lien ket tng ng vi nhom gen lien ket

4 . Y ngha cua di truyen lien ket :- lien ket gen lam han che s xuat hien cua bien d to hp , bao toan nhng

tnh trang giong bo me- Lien ket gen am bao s di truyen bean vng tng nhom tnh trang qui nh

bi cac gen tren 1 NST- Trong chon giong , tien hanh lai tao ra giong mi co cac gen qu ( qui nh

nhom tnh trang tot ) nam trong cung 1 nhom gen lien ket luon i kem vi nhauII . LIEN KET GEN KHONG HOAN TOAN :

1 .Th nghiem : Khi cho lai ruoi cai F1 than xam canh dai giao phoi vi ruoicai than en canh ngan . Thu c F2 : 41% than xam canh dai ; 41% than encanh ngan ; 9% than xam canh ngan ; 9% than en canh dai .

* Nhan xet :- Neu ch co hien tng lien ket gen th F2 ch co 2 loai kieu hnh la

xam, dai va en, ngan .-Thc te F2 co 4 loai kieu hnh , trong o co 2 loai kieu hnh mi la

than xam canh ngan va than en , canh dai vi t le thap la ket qua cua hien tnghoan v gen gia 2 trong 4 cromatit cua cap NST kep

2 Giai thch bang c s te bao hoc : ( ve s o phan li NST )- Viet s o lai ( HS t viet )

- Tan so hoan v gen (P) = t le % cac loai giao t co gen hoan vVD : th nghiem tren th => tan so hoan v = 9% Bv + 9%bV = 18 %


27/40

27


B PHNG PHAP GIAI

I TNH SO LOAI VA THANH PHAN GIAO T1) Cac gen lien ket hoan toan :a) Tren 1 cap NST ( 1 nhom gen )- Cac gen ong hp t 1 loai giao tV du :

Ab

Ab 1 loai giao t Aa ;ABd

ABd ABd

- Neu co 1 cap gen d hp tr len 2 loai giao t t le tng ngV du :

Ab

AB AB = Ab ;ab

AB AB = ab ;abd

ABD ABD = abdb) Tren nhieu cap NST ( nhieu nhom gen ) neu moi nhom cen co t nhat 1 cap

gen d hpSo loai giao t = 2n vi n = so nhom gen ( so cap NST )

* Tm thanh phan gen moi loai giao t : dung s o phan nhanh hoac nhan aiso la moi loai giao t cua moi nhom gen nay phoi hp u kieu vi cac loaigiao t cua nhom gen kia

V du : C the co KGab

AB.de

DE 4 loai giao t : AB.DE : AB.de : ab.DE : ab.deV so nhom gen la 2 so loai giao t 22 = 4 loai giao t

2) Cac gen lien ket khong hoan toan .Moi nhom gen phai cha 2 cap gen d hp tr len mi phat sinh giao t

mang to hp gen cheo ( giao t HVG) trong qua trnh giam phana) Trng hp 2 cap gen d hp :* So loai giao t : 22 = 4 loai t le khong bang nhau

Thanh phan gen :+ 2 loai giao t bnh thng mang gen lien ket t le moi loai giao t nay

> 25% .+ 2 loai giao t HVG mang to hp gen cheo nhau do 2 gen tng ng

oi cho , t le moi loai giao t nay < 25% .

V du : C the co KG abAB lien ket khong hoan toan tao giao t :+ 2 loai giao t bnh thng t le cao la : AB = ab > 25% .+ 2 loai giao t HVG t le thap la: Ab = aB


28/40

28


*So loai giao t tao ra = 8 loai*Thanh phan KG cac loai giao t :

+ Giao t bnh thng : ABD =abd+ Giao t TC 1 cho : Abd= aBD = X1 ; ABd = abD = X2+ Giao t TC 2 cho : AbD = X3

Khong xay ra TC 2 cho :VD : C the co KG

abd

ABD

*So loai giao t tao ra = 6 loai giao t* Thanh phan KG cac loai giao t :

+ Giao t bnh thng : ABD =abd+ Giao t TC 1 cho : Abd= aBD = X1 ; ABd = abD = X2

II . TAN SO TRAO OI CHEO VA KHOANG CACH TNG OI GIA 2GEN TREN 1 NST

1) Tan so TC (tan so HVG ) : pTan so TC gia 2 gen tren cung NST bang tong t le 2 giao t HVG .Do o : T le moi loai giao t bnh thng =

2

%100 p =2

1 p

T le moi loai giao t HVG =2

p

* Tan so TC the hien lc lien ket gia cac gen . Thng cac gen co xuhng chu yeu la lien ket tan so HVG < 50% .

Trong trng hp ac biet , cac te bao sinh duc s khai eu xay ra TC giong

nhau tan so HVG p = 50% . Do o , c the d hp t kep cho 4 loai giao t t letng ng giong vi trng hp phan li oc lap .2) Khoang cach tng oi gia cac gen tren cung 1 NST

+Tan so HVG the hien khoang cach tng oi gia 2 gen : 2 gen cang namxa nhau th tan so HVG cang ln va ngc lai cac gen cang nam xa nhau th tan soHVG cang nho .

+ Da vao tan so HVG => khoang cach gia cac gen => v tr tng oi(locut) trong nhom gen lien ket .

Qui c : 1 cM ( centimorgan) = 1% HVG

III. TNH TAN SO HOAN V GEN1) Trong phep lai phan tch :

Tan so HVG p = (So ca the hnh thanh do TC : Tong so ca the nghiencu ) x100%


29/40

29


V du : Lai phan tch ruoi cai than xam canh dai thuoc KG oiaB

Ab c the he lai

gom 376 con xam ngan : 375 con en dai : 124 con xam dai : 125 con en nganGiai

Xam dai va en ngan la 2 KH do TC tao ra :

=> Tan so HVG =125124375376

125124

. 100 = 25%

2) Trong cac phep lai khac . giai bang ai so+ at P : Tan so HVG => t le giao t HVG la

2

p

t le giao t BT la2

1 p

+ Davao loai KH ma e bai cho biet lap t le :T le cac KG lam nen KH theo an so p = So ca the thu oc KH biet c

: Tong so ca the thu c

V du : Cho cay than cao hat dai co KG aBAb t thu phan F1 thu c 4000 cay ,trong o co 260 cay thap tron

Giai

+ at p = Tan so HVG => t le giao t HVG la2

p

+ F1 thu c cay thap tron (ab

ab) co t le4000

160 =100

4

T le KG lam nen cay thap tron la (2

p )2 .ab

ab

=> phng trnh (2

p )2 =100

4 c p = 40%

IV . CACH NHAN NH QUY LUAT DI TRUYEN1) Da vao phep lai khong phai la phep lai phan tch

+ Tm t le phan tnh ve KH the he lai oi vi moi loai tnh trang .+ Nhan 2 t le KH rieng cua 2 loai tnh trang vi nhau . Neu ket qua khong

phu hp e bai => 2 cap gen quy nh 2 cap tnh trang o nam tren cung 1 cap NST2) Da vao phep lai phan tch

Neu ket qua lai chng to ca the d hp kep cho 2 loai giao t hoac 4 loai giao tco t le khong bang nhau => 2 cap gen nam tren cung 1 cap NST


30/40

30


PHAN III. TNG TAC GENA . TOM TAT LY THUYET

I. TNH TRANG A GEN ( tng tac gen / Nhieu gen chi phoi mot tnhtrang )

1 . TAC ONG BO TRa. Khai niem :

Tac ong bo tr la kieu tac ong qua lai cua 2 hay nhieu capgen thuoc nhng locut khac nhau ( khong alen ) lam xuat hien 1 tnh trang mib. Noi dung nh luat :

+ Hai hoac nhieu gen khong alen co the tac ong len s hnh thanh tnhtrang

+ Cac dang tac ong khac nhau cho t le kieu hnh F2 la bien dangcua ( 9: 3: 3: 1 )

c. Cac dang tac ong bo tr : Cac t le : 9: 3: 3: 1 ; 9: 6: 1 : 9:7 . ta ch xet1 dang t le : 9: 6: 1.

c 1 . Th nghiem 1 : khi lai 2 th b qua tron thuan chung vi nhau , F2 thuc 3 loai kieu hnh vi t le : 9 det : 6 tron : 1 dai

c 2 Giai thch : F2 co t le kieu hnh 9: 6:1 = 16 to hp = 4 loai giao t (?F1)x 4loai giao t (?F1) . Ngha la F1 moi ben cho 4 loai giao t vi t le bang nhau.Vay F1 moi ben eu phai d hp t nhat 2 cap gen , nhng ch quy nh 1 tnhtrang . Vay tnh trang dang qua do 2 cap gen nam tren 2 cap NST tng ongkhac nhau tac ong tac ong qua lai cung qui nh

- Qui c gen : gia s 2 cap gen tng tac la Aa va Bb :

+ Cac kieu gen co 2 gen troi (A-B-) tac ong bo tr hnh thanh bquaDE5T.

+ Cac kieu gen ch co 1 gen troi : A-bb hoac aaB- qui nh b qua tron+ Kieu gen co 2 cap gen lan (aabb) tac ong bo tr hnh thanh b qua

dai

- S o lai :+ PTC : AAbb( qua tron ) x aaBB( qua tron )+GP : Ab aB

+ F1 AaBb ( 100% qua dai )+ F1 x F1: AaBb (qua dai ) x AaBb ( qua dai )+GF1 : AB , Ab , aB , ab ; AB , Ab , aB , ab

F2 : 9 ( A- B- ) : 3 (A- bb) : 3( aaB- ) : 1 aabb9 qua det 6 qua tron 1 qua dai

2. TAC ONG AT CHE :a. Khai niem : la trng hp mot gen nay kiem ham hoat ong cua mot gen

khac , khong cung locut.


31/40

31


b. Cac dang tng tac at che : At che gen troi ( 12:3:1; 13: 3 ) va at che dogen lan ( 9: 4: 3: ) . Ta ch xet 1 dang t le 12 :3 :1

b1. Th nghiem : Cho lai nga long xam thuan chung vi nga longhung thuan chung , dc F1 toan long xam . Cho cac con nga F 1 giao phoi vi nhau, F2 co s phan li kieu hnh theo t le : 12xam : 3 en : 1 hung

b2 . Giai thch : ( tng t tac ong bo tr)


32/40

32


* Trng hp A at che :-Cac kieu gen co mat gen troi

A ( A-B- ; A- bb ) at che hoat ongcap gen B, b qui nh long xam .

- Cac kieu gen (aaB- ) co gen

troi B khong b at che qui nh mauen

- Kieu gen co 2 cap gen lanaabb qui nh long hung

- S o lai :+ PTC : AABB( xam ) x

aabb( hung )+GP : Ab

aB+ F1 AaBb (100% xam )

+ F1 x F1: AaBb (xam ) xAaBb ( xam )

+GF1 : AB , Ab , aB , ab ;AB , Ab , aB , ab

F2 : 9 ( A- B- ) : 3 (A-

bb) : 3( aaB- ) : 1 aabb12 xam3 en 1

hung

* Trng hp B at che :-Cac kieu gen co mat gen troi

B ( A-B- ; aaB- ) at che hoat ongcap gen B,b qui nh long xam .

- Cac kieu gen (A-bb ) co

gen troi A khong b at che qui nhmau en

- Kieu gen co 2 cap gen lanaabb qui nh long hung

- S o lai :+ PTC : AABB( xam ) x

aabb( hung )+GP : Ab

aB+ F1 AaBb (100% xam )

+ F1 x F1: AaBb (xam ) xAaBb ( xam )

+GF1 : AB , Ab , aB , ab ;AB , Ab , aB , ab

F2 : 9 ( A- B- ) : 3

(aaB-) : 3( A-bb ) : 1 aabb12 xam3 en 1

hung3 TAC ONG CONG GOP :

a. Khai niem : Tac ong cong gop la kieu tac ong cu nhieu gen , trong domoi mgen ong gop 1 phan nh nhau vao s phayt trien cua cung 1 tnh trang .

b. Th nghiem : Lai giong luau m hat o thuan chung(TC) vi giong hattrang TC , F1 thu dc toan hat do en F2 co s phan li kieu hnh : 15 o : 1 trang.Mau do co o am nhat khac nhau , t o tham en o nhat

c. Giai thch : Mau sac hat luau m F2 co t le phan li kieu hnh la 15 :1gom 16 to hp , nen mau sac phai do 2 cap gen nam tren 2 cap NSt khac nhautng tac qui nh .

- Qui c : Gia s 2 cap gen tng tac la Aa, Bb


33/40

33

CD SINH 12 LUYN THI IHC Trn Thin 0913.430 999 TRUNG TM TOAN OLYMPIC ISI+ Cac kieu gen co mat gen troi ( A-B- : A-bb: aaB-) eu qui nh hat mau

o . So lng gen troi trong kieu gen cang nhieu th mau o cang am.+ Kieu gen khong co mat gen troi nao ca (aabb) qui nh hat trang

- S o lai :+ PTC : AABB(o ) x aabb( trang )

+GP : Ab aB+ F1 AaBb ( 100% o )+ F1 x F1: AaBb (o ) x AaBb ( o )+GF1 : AB , Ab , aB , ab ; AB , Ab , aB , ab

F2 : 9 ( A- B- ) : 3 (A- bb) : 3( aaB- ) : 1 aabb15 o ( am nhat ) 1 trang

II . GEN A HIEU ( mot gen chi phoi nhieu tnh trang )1 . V du

- au Ha Lan : Th hoa tm th hat nau , nach la co cham en ; th hoatrang th hat nhat nach la khong cham nau .- ruoi Giam :Cac gen qui nh canh ngan th ot than ngan , long cng , hnh

dang c quan sin h duc thay oi , de trng t , tuoi tho giam au trung suy yeu . Congen quy nh canh dai th than ot dai , long mem e trng nhieu , tuoi tho cao ,au trung manh

2. Giai thch :Moi nhom tnh trang tren deu do 1 gen qui nh .

B PHNG PHAP GIAII . CAC KIEU TNG TACMoi kieu tng tac co 1 t le KH tieu bieu da theo bien dang cua (3:1)2 nh

sau :1 Kieu ho tr co 3 t le KH : 9: 3:3:1 ; 9:6: 1 ; 9: 7 .

a) Ho tr gen troi hnh thanh 4 KH : 9:3:3:1A-B- A-bb aaB- aabb thuoc t le : 9:3:3:1

b) Ho tr gen troi hnh thanh 3 KH : 9:6: 1A-B- ( A-bb = aaB- ) aabb thuoc t le : 9:6: 1c) Ho tr gen troi hnh thanh 2 KH : 9:7

A-B- ( A-bb = aaB- = aabb ) thuoc t le : 9:72. Kieu at che co 3 t le KG : 12:3:1 ; 13:3 ; 9:4:3

a) At che gen troi hnh thanh 3 KH : 12:3:1(A-B- = A-bb) aaB- aabb thuoc t le : 12:3:1


34/40

34


b) At che gen troi hnh thanh 2 KH : 13: 3(A-B- = A-bb = aabb ) aaB- thuoc t le : 13:3

c) At che gen lan hnh thanh 3 KH : 9:4:3A-B- ( A-bb = aabb ) aaB- thuoc t le : 9:4:3

3. Tac ong cong gop ( tch luy) hnh thanh 2 KH : 15 :1A-B- ( A-bb = aabb ) aaB-

Tong quat n cap gen tac ong cong gop => t le KH theo he so moi so hang trongtrien khai cua nh thc Newton ( A+a)n

II. XAC NH SO CAP GEN TNG TAC (e nhan nh quy luat ditruyen)

Thng da vao ket qua phan tnh the he lai => so kieu to hp giaot => so loai giao t cua bo me => so cap gen tng tac .

T le kieu phan tnh co the thuoc 16 kieu to hp nh : 9:6:1 ; 9:7hoac 8 kieu to hp nh 4:3:1 ; 6: 1:1 . Hoac 4 kieu to hp nh :3: 1 ; 1:2:1 ( xem bang ghi cac kieu tng tac tng ng )

III . D OAN KIEU TNG TACSau khi xac nh kieu tng tac , ong thi xac nh kieu gen bo me => viet

s o lai co the co cua phep lai o e thay t le KG theo dang nao , oi chieuvi t le KH cua e bai => d oan kieu tng tac

PHAN IV DI TRUYEN LIEN KET VI GII TNH

I . XAC NH KIEU NST GII TNH1. Trong thien nhien , a gap 1 so kieu NST gii tnh nh sau : XX, XY , XO

( XX la ong giao t , XY hoac XO la d giao t )- c XY , cai XX : ngi , ong vat co vu , ruoi giam - c XX , cai XY : cac loai chim , bm tam , ech nhai , bo sat .- c XO ; cai XX : bo xt , chau chau , rep

- c XX ; cai XO : bo nhay .2. Neu ca the c e cap trong e bai khong neu loai nao => kieu NST giitnh co the xac nh theo 2 cach :

- Da vao ca the mang tnh trang lan the he co t le phan tnh 3:1 . V tnhtrang nay de xuat hien ca the XY => gii tnh cua ca the o thuoc NST gii tnhXY


35/40

35

CD SINH 12 LUYN THI IHC Trn Thin 0913.430 999 TRUNG TM TOAN OLYMPIC ISI- Dung cach loai suy , lan lt th tng kieu NST gii tnh => kieu nao cho ket

qua phu hp vi e bai th nhanV du : cho 1 ca the mang 1 cap gen d hp quy nh canh thang giao phoi vi cathe khac c F1 gom 256 con canh thang : 85 con canh cong ( ch toan con c )=> - Cap gen d hp quy nh canh thang => canh thang la tnh trang troi , canh

cong la tnh trang lan .- F1 co t le 3 canh thang : 1 canh cong . Nhng tnh trang lan canh cong ch

bieu hien con c => NST gii tnh cua con c la XY , con cai XX .II . DI TRUYEN LIEN KET VI GII TNH

A. Khai niem : la hien tng di tuyen cac tnh trang ma ca gen xac nhchung nam tren cac NST gii tnh

B. Gen tren NST X ( Qui luat di truyen cheo )1 .Th nghiem : Moocgan a lai ruoi giam mat o vi mat trang

-Lai thuan :+ P : (mat o ) x ( mat

trang )+ F1 : 100% mat o+ F2 : 3 mat o : 1 mat trang (

toan con c )-Lai nghch :

+ P : (mat trang ) x ( mat

o )+ F1 : 1 mat o : 1 mat trang+ F2 : 1 mat o : 1 mat trang

: 1 mat o : 1 mat trang


36/40

36


2 . Giai thch :- F1 ong loat mat o , theo nh luat ong tnh th mat o troi hoan

toan so vi mat trang .Qui c : W : mat o ; w : mat trang .

-Neu gen nam tren NST thng th F2 ( trong phep lai thuan ) mattrang phan bo ca gii c va cai . Thc te F2 mau mat trang chco con c , V vay gen qui nh mau mat ruoi phai nam trenNST gii tnh X , khong co alen tren Y .

-S o lai :+ Phep lai thuan :

P : XWXW ( mat o ) x XwY( mat trang )G : XW , XW ; Xw , YF1 : XWXw , XWY ( 100% mat o )

F1x F1 : XWXw x XWYG: XW , Xw ; XW , YF2 : XWXW : XWXw :XWY : XwY

3 mat o : 1 mat trang+ Phep lai nghch:

P : XwXw ( mat trang ) x XWY( mat o )G : Xw ; Xw , YF1 : XWXw (50% mat o ) , XwY ( mat trang)

F1x F1 : XW

Xw

x Xw

YG : : XW , Xw ; Xw , YF2 : XWXw : XwXw : XWY : XwY

1 mat o : 1 mat trang : 1 mat o : mat trangVay, phep lai thuan gen lan tren X do bo truyen cho con gai va bieuhien chau trai

3 . Noi dung nh luat :

-Di truyen cheo : tnh trang cua bo truyen cho con cai (gai) , tnhtrang cua me truyen cho con c .- Hai phep lai thuan nghch cho: ket qua khac nhau .

C . GEN TREN NST Y :( quy luat di truyen thang )-NST Y a so loai hau nh khong mang gen , nen hau nh gen

tren NST X hiem co gen tng ng tren Y . Tuy nhien , 1 so loai ongvat , NST Y cung mang gen .


37/40

37

CD SINH 12 LUYN THI IHC Trn Thin 0913.430 999 TRUNG TM TOAN OLYMPIC ISI- NST Y ngi co oan mang gen tng ng vi gen tren X ,

nhng cung co oan gen tren Y ma khong co gen tng ng tren XV du : ngi tat dnh ngon tay so 2 va so 3 do gen lan (a) tren

NST Y gay ra va ch bieu hien nam giiP : XX x XYa

G : X ; X , YaF1 : XX ( 50% gai BT ) : XYa ( 50% trai dnh ngon )

-Noi dung di truyen thang : tnh trang qui nh bi gen nam trenNST Y di truyen 100% cac cap NST gii tnh XY ( 100% con trai)

D. Y ngha : hien tng di truyen lien ket vi gii tnh c ng dunge phan biet gii c hoac gii cai giai oan sm phat trien cua cathe luc hnh thai gii tnh cha the hien ra kieu hnh , nh o co the

chon loc e tang nang suat .V du : ga ngi ta s dung gen troi A tren NST gii tnh X xacnh long van , e phan biet trong , mai khi mi n . Ga trong con XA

XA co long van au ro hn so vi con mai XA Y .II CACH NHAN NH QUY LUAT DI TRUYEN :

1. Da vao ket qua cua phep lai thuan nghch- Neu ket qua lai thuan nghch khac nhau th gen quy nh tnh trang

c xet nam tren NST gii tnh .

- Neu tnh trang a cho thay xuat hien ch gii c qua cac the he (di truyen thang ) = > gen nam tren NST Y . Ngc lai th gen nam trenNST X

2. Da vao s di truyen cheo hoac tnh trang bieu hien khongong eu tren gii c va cai :

a. Di truyen cheo : tnh trang cua con c giong tnh trang cua meva tnh trang cua cai con giong bo la co s di truyen cheo => gen nam trenNST gii tnh X

b . Tnh trang khong bieu hien ong eu 2 gii :Cung 1 the he nhng tnh trang nao o ch xuat hien gii c , congii cai th khong hoac ngc lai => gen nam tren NST gii tnh

Chu y : thc te gen nam tren NST gii tnh cung co nhng trnghp tac ong vi gen nam tren NST thng e hnh thanh 1 tnh trang .Cung co cac gen nam tren cung 1 NST gii tnh X tac ong rieng re hoactng tac qua lai vi nhau .


38/40

38


*** CHU Y CACH NHAN NH CAC QUY LUAT DI TRUYEN1. Cac quy luat Menden : (phan li oc lap )- Hai hay nhieu cap gen nam tren 2 hay nhieu cap NST tng

ong

- Hai hay nhieu cap gen quy nh 2 hay nhieu cap tnh trang2. Cac quy luat cua Moocgan :

- Hai hay nhieu cap gen cung nam tren 1 cap NST- Hai hay nhieu cap gen cung quy nh 2 hay nhieu tnh trang3. Cac qui luat tng tac gen :- Hai hay nhieu cap gen nam tren 2 hay nhieu cap NST- Hai hay nhieu cap gen cung qui nh 1 cap tnh trang

PHAN V . OT BIEN

A. OT BIEN GEN (BG)

I . Cac dang ot bien gen va s bien oi trong cau truc cua gen :- ot bien gen la nhng bien oi trong cau truc gen 1 hoac 1 so cap

Nu .- cau truc cua gen b bien oi ve so lng hoac thanh phan hoac trnh

t cac Nu trong gena) So sanh gen bnh thng va gen ot bien nhan thay :Hai gen co so Nu khong thay oi -> gen ot bien co the bien oi ve

thanh phan va trnh t cac Nu :- ot bien thay the kieu ong hoan hoac d hoan .

+ Thay the kieu ong hoan : thay the 1 cap A-T bang 1 capG-X hoac thay the 1 cap G-X bang 1 cap A-T

+ Thay the kieu d hoan : thay the 1 cap A-T bang 1 cap T-

A hoac thay the 1 cap G-X bang 1 cap X-G- ot bien gen dang ao v tr .b) So sanh gen bnh thng va gen ot bien nhan thay :Hai gen co so lng tng loai Nu giong nhau -> ( khong thay oi ve

thanh phan va so lng Nu ) -> Gen B co bien oi ve trnh t Nu :-BG dang thay the kieu d hoan .-BG dang ao v tr


39/40

39


c) So sanh gen bnh thng va gen ot bien nhan thay :Hai gen co so lng Nu giong nhau , hai gen khac nhau ve thanh

phan tng loai Nu => BG dang thay the kieu ong hoand)So sanh gen bnh thng va gen ot bien nhan thay :Hai gen co so lng Nu chenh lech nhau 1 cap Nu :

-BG dang them 1 cap Nu-BG dang mat 1 cap Nu

II. T le gen ot bien :-Gen tien B : gen co bien oi cau truc 1 mach . Gen tien B co the

c enzim sa cha thanh gen bnh thng .-Gen B : gen co bien oi 1 cap Nu tren 2 mach n .

+ Gen < nhan oi > gen tien B nhan oi > gen Bx=1 x=1

+ T le gen ot bien = ( So gen B : Tong so gen tao ra ) . 100

B. OT BIEN NHIEM SAC THE ( BNST )I. ot bien the d boi NST :- La B xay ra tai 1 hay 1 so cap cua NST .Co cac dang : the 3 nhiem(2n+1 ) ; the 1 nhem ( 2n- 1) ; the khuyet nhiem (2n -2) ; the a nhiem- C che : c the 2n gam phan 1 so te bao sinh duc s khai co 1 hoa 1 socap nao o cua NST khong phan li tao ra giao t B ( n+1) hoac (n-1)

hoac (n-2 )P : 2n x 2nGp : (n+1) (n-1) nF (hp t ) : 2n+1 NP the 3 nhiemF (hp t ) : 2n-1 NP the 1 nhiem

II .The a boi ( 3n hoac 4n )- The a boi la nhng bien oi tronng toan bo cau truc NST , ln hn boiso 2n nh : 3n , 4n , 5n , 6n -C che :

+ Te bao soma 2n hoac te bao tien phoi 2n , trong nguyen phan cacNST khong pha li tao ra te bao 4n , cac te bao 4n nguyen phan bnhthng cho ra cac te bao con 4n

TB soma 2n )(DBNP TBsoma 4n NP Mo , c quan 4nTB tien phoi 2n )(DBNP TBtien phoi 4n NP c the 4n


40/40

CD SINH 12 LUYN THI IHC Trn Thin 0913.430 999 TRUNG TM TOAN OLYMPIC ISI+ Te bao sinh duc 2n giam phan , s khong phan li cac NST trong 1

lan phan bao tao ra giao t ot bien 2n .Neu giao t 2n ket hp giao t 2n hp t 4n

P : 2n x 2nGp 2n 2n

F ( hp t) 4n=>F (hp t ) 4n NP c the 4n

Neu giao t 2n ket hp giao t n hp t 3nP : 2n x 2nGp 2n nF ( hp t) 3n=> F (hp t ) : 3n NP c the 3n

cong thuc sinh hoc 12 tham khao.pdf

Documents