Sex Linked Cross

1
Sex - Linked Cross
Trait related to sex of organism
Human body cells
46 chromosomes
23 pairs
22 pairs
1 pair
Autosomes
Sex chromosomes
2
Who determines the sex of a child?
Father
In which sex do sex-linked traits usually show?
genes
Sex linked genes
Ex. Hemophilia Colorblindness
Usually recessive
3
Zygote
4
Sex-linked Problems
Key N Normal n Colorblindness Cr
XNXN x XnY Gam XN XN x Xn
Y PS
Geno 2XNXn 2XNY Pheno 2 Female Normal
Carriers 2 Male Normal
XN
Xn
Xn
XN
F1
XN
Y
XN
Y
5
Sex-linked Problems - Cont
Key N Normal n Colorblindness Cr
XNXn x XNY Gam XN Xn x XN
Y PS
Geno 1XNXN 1XNXn 1XNY 1XnY Pheno 1
Female Normal 1 Female Normal Carrier 1 Male
Normal 1 Male Colorblind
XN
XN
Xn
XN
F1
Xn
Y
XN
Y
6
Sex-linked Practice Problems
1. Key N Normal n
Colorblindness Cr XNXn x XNY Gam XN
Xn x XN Y PS
Geno 1XNXN 1XNXn 1XNY 1XnY Pheno 1
Female Normal 1 Female Normal Carrier 1 Male
Normal 1 Male Colorblind
XN
XN
Xn
XN
F1
Xn
Y
XN
Y