thu hoa

bien so xe may gom 2 phan.phan chu va phan so.phan chu la day 2 chu cai hoac 1 chu cai.phan so la day gom 5 chu so.

hoi co bao nhieu xe may co bien so khac nhau .biet rang phan chu lay trong 26 chu cai va phan so gom 10 so tu 0 den 9

co mot ca the mang 2 cap gen cho 4 kieu giao tu ti le bang nhau .neu de ca the do tu thu phoi thi doi con F1 co ti le kieu gen la bao nhieu

ngan hang de thi gom 100 bo,moi de thi co 5 cau ,1 hoc sinh thuoc 80 cau.tim xac suat de hoc sinh do rut ngau nhien duoc 1 de ma trong do co 4 cau hoc sinh do hoc thuoc.

co 3 thung dung cac mau.thung1co 4trang 2den,thung2 co 5trang3den,thung 3 dung 2 trang 2den.lay ngau nhien 1 mau tu thung 1 tron vao thung 2,lay ngau nhien mot mau tu thung 2 tron sang thung 3,lay ngau nhien mot qua cau tu thung 3 tron sang thung1

a,tinh sac xuat de thung 1 co 3 trang 3den

b,voi sac xuat lon nhat thi thanh phan thung mot co may trang may den,

cam on moi nguoi

o ca chua cay F1 la cay cao qua do ,cho chung tu thu phan voi nhau,F2 thu duoc 1048 cay cao vang 199 cay cao do 1052 cay thap do,201cay thap vang,bien luan va viet so do lai.biet NST o 2 ben la ging nhau

trong mot moi truong vat chat dan hoi co 2 nguon ket hop A,B cach nhau 10cm,co cung tan so va nguoc pha.khi do tai vung giua 2 nguon ,nguoi ta quan sat tha·yuat hien 10 day dao dong cuc dai,cat A,B thanh 11doan ma 2 doan o 2 dau chi dai bang mot nua cac doan.cho biet toc do truyen song cua moi truong la 60cm\s.tinh tan so

cau 1: 1 soi day dan hoi manh dai co dau O dao dong voi tan so f thay doi duoc trong khoang tu 40 den 53 HZ theo phuong vuong goc voi soi day.song tao thanh lan truyen voi v=5m/s.voi f=40 tinh buc song,xac dinh f biet 1 diem M tren day cach O la 20cm dao dong cung pha voi vat

cau 2:soi day dan hoi rat dai co dau A dao dong vs tan so f theo phuong vuong goc vs soi day.a=4cm,v=4m/s.xet tai 1 diem M tren day cach a la 28cm.lay M luon dao dong lech pha vs a 1 goc denta phi[2k+1]phi/2.tinh buc song biet f dao dong tu 22 den 26 HZ.viet phuong trinh dao dong biet u=4cost wt[cm]

cho lai AaBbDd voi AaBbDd .tinh xac suat de thu duoc 2 cap gen dong hop 1 cap di hop;3 cap gen di hop