F1 co ti le kieu hinh xap xi 9:3:3:1\(\Rightarrow\)P di hop 2 cap gen

So do lai minh hoa:

P: AaBb(den xu) x AaBb(den xu)

G_P: 1/4AB ,1/4Ab 1/4AB,1/4Ab

1/4aB,1/4ab 1/4aB,1/4ab

F_1:1/16AABB,2/16AABb,1/16AAbb,2/16AaBB

4/16AaBb,2/16Aabb,1/16aaBB,2/16aaBb,1/16aabb

KH:9 den xu:3 den tron:3trang xu:1 trang tron

L=4080 angtron\(\Rightarrow\)N=4080 x 2 / 3,4=2400

-So Nu tung loai cua gen troi

2A+2G=2400(1) ; 7A-9G=0(2) tu (1) va (2) ta co

A=T=675 ; G=X=525

-So nu tung loai cua gen lan

2T+2X=2400(3) ; 3T-13X=0(4) tu (3)va(4) ta co

A=T=975 ; G=X=225

a)So luong tung loai Nu o F1 la

A=T=675+975=1650 ; G=X=525+225=750

b)So luong tung loai Nu cua moi loai hop tu o F2 la

-BB

A=T=675 x 2=1350; G=X=525 x 2=1050

-Bb

A=T=675+975=1650;G=X=525+225=750

-bb

A=T=975 x 2=1950;G=x=225 x 2=450

Goi x la so lan nguyen phan cua te bao sinh duc.512 tinh trung mang Y\(\Rightarrow\)Tong so tinh trung la 512 x 2=1024.Ta co:

2^x x 4=1024\(\Rightarrow\)x=8

Vay so lan nguyen phan cua te bao sinh duc tren la 8.

Moi truong te bao cung cap nguyen lieu de hinh thanh nen 9690 NST don moi tuong duong 9690 nen ta co:

2n x (2^x-1)=9690\(\Rightarrow\)2n=38

Ta thay Bb x BB tao ra chat chan co tinh trang troi,dd x dd tao ra chat chan co tinh trang lan nen ta chi tim ti le loai kieu hinh mang 1 tinh trang troi va 1 tinh trang lan

Vay ti le loai kieu hinh mang 2 tinh trang troi va 2 tinh trang lan o F₁ cua phep lai la

3/4 x 1/4 +1/4 x 3/4=3/8

Xet rieng tung tinh trang ta co:

-Tinh trang mau qua:

O F₁ co ti le 3 qua do :1 qua vang co 4 to hop giao tu\(\Rightarrow\)P di hop Aa x Aa

-Tinh trang hinh dang qua:

O F₁ xuat hien 100% qua det\(\Rightarrow\)P: bb x bb

Vay de F₁ co ti le 3 do det : 1 vang det thi phai chon

P: Aabb(do det) x Aabb(do det)

-So kieu gen cua gen A la:

2(2+1)/2=3

-So kieu gen cua gen B la:

2(2+1)/2=3

Vay so kieu gen khac nhau trong quan the la

3x3=9(kieu gen)

Tach rieng tung phep lai ta co:

P: Aa(vang) x Aa(vang)

F₁: 3vang : 1xanh

P: BB(hat tron) x Bb(hat tron)

F₁:100% hat tron

Vay:

P: AaBB x AaBb

F₁:(3vang:1 xanh)x(100%tron)=3vang tron :1xanh tron

F₂ 3 ca vay do:1 ca vay trang \(\Rightarrow\)vay do troi hoan toan so voi vay trang.Ca vay trang toan con cai\(\Rightarrow\)Gen quy dinh tinh trang mau vay nam tren vung khong tuong dong cua NST X.

Quy uoc :A- vay do ,a- vay trang

P: X^AX^A (vay do) x X^aY (vay trang)

G_p: X^A 1/2X^a ,1/2Y

F₁: 1/2X^AX^a , 1/2X^AY

F₁xF₁: X^AX^a(vay do) x X^AY(vay do)

G_F1: 1/2X^A,1/2X^a 1/2X^A,1/2Y

F₂:1/4X^AX^A , 1/4X^AY , 1/4X^AX^a , 1/4X^aY

KQ:3vay do:1vay trang

Khi thuc hien phep lai nghich voi phep lai tren thi

P:X^aX^a(vay trang) x X^AY(vay do)

\(\Rightarrow\)F₂ co :

Ti le kieu gen:1X^AX^a : 1X^AY : 1X^aX^a : 1X^aY

Ti le kieu hinh:1vay do:1vay trang(1duc vay do:1cai vay do:1duc vay trang:1cai vay trang)

*Luu y: O ca con duc co cap NST gioi tinh la XX con cai la XY

a)Cao trang lai voi thap do\(\Rightarrow\)F₁ toan than cao hoa do\(\Rightarrow\)cao do troi hoan toan so voi thap trang.

Quy uoc:A-than cao,a-than thap,B-hoa do,b-hoa trang

So do lai

P: AAbb(cao trang) x aaBB(thap do)

G_p: Ab aB

F_{1 AaBb(cao do)}

b)F₁ lai phan tich

P_b: Aa​Bb(cao do) x aabb(thap trang)

_Gb:1/4AB,1/4Ab,1/4aB,1/4ab ab

F_b:

-KG:1/4AaBb,1/4Aabb,1/4aaBb,1/4aabb

-KH:1 cao do:1 cao trang:1 thap do:1 thap trang

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