1. SEX-LINKED and SEX INFLUENCED TRAITS

2. SEX DETERMINATION
XX =
female
male
Xy =

3. Who decides? X X Mom can give X X Dad can give X or y y X X X X X y
Dads determine sex of babies.
If dad gives X with mom’s X = girl
If dad give y with mom’s X = boy

4. SEX CHROMOSOMES CAN CARRY OTHER GENES TOO = ___________________
SEX LINKED TRAITS

5. SEX LINKED TRAITS show up in different % in males and females because they move with the sex chromosomes

6. Sex chromosomes can carry other genes
Y-LINKED GENES:
Genes carried on Y chromosome
EX: Hairy pinna
Y linked
males.
_________genes only show up in _______

7. Make a cross with a y-linked gene
Hairy ears is a
________________
________________ trait
Y linked
dominant H
Use ______ for hairy ears.
Use ______ for recessive normal ears.
On y chromosome so write it as ________ h yH

8. Make a cross with a y-linked geneX X
ALL GIRLS =
____________
X X
X X X
Normal ears
ALL BOYS =
____________
X yH
Hairy ears yH
X yH

9. Sex chromosomes can carry other genes
X-LINKED GENES: Genes carried on the X chromosome
EX: _____________
_____________
_________________________
Hemophilia
Colorblindness
Duchenne Muscular Dystrophy

10. Make a cross with an X-linked gene
Hemophilia is an
________________
________________ disease
X-linked
recessive H
Use ______ for normal dominant blood clotting gene.
Use ______ for recessive hemophilia gene.
On X chromosome so write it as ________ h Xh

11. Mother
Without hemophilia = X X
Without hemophilia = X X
With hemophilia = X X
Father
Without hemophilia = X y
With hemophilia = X y
H H
H h
CARRIER
h h H h

12. Make a cross with an X-linked gene
Carrier Mom X
Normal dad XH y Xh
GIRLS
_______ = normal
_______ = look normal
but are CARRIERS
BOYS
_______ = hemophilia
1/2
XHXH XHy
XHXh Xh y
1/2
1/2
1/2

13. Make a cross with an X-linked gene
Colorblindness is an
________________
________________ disease
X-linked
recessive B
Use ______ for normal dominant color gene
Use ______ for recessive colorblind gene.
On X chromosome so write it as ________ b Xb

14. Mother
normal vision = X X
normal vision = X X
colorblind = X X
Father
normal vision = X y
colorblind = X y
B B
B b
CARRIER
b b B b

15. Color blindness is sex linkedXb y XB
HOMOZYGOUS Normal Mom X
colorblind dad
XBXb XBy
XBXb XBy
GIRLS = _______________
BOYS = ________________
100% carriers
100% normal

16. SEX LINKED TRAITS show up in different % in males and females because they move with the sex chromosomes

17. Y linked genes ________ show up in males.
X linked recessive genes appear __________ in males than females.
Females can be __________ for X linked recessive traits.
Males can _________ carriers for X linked
recessive genes. The either have trait OR are normal.
ONLY
more often
CARRIERS
NEVER BE

18. SEX INFLUENCED TRAITS
Genes ___________ on sex chromosomes BUT affected by ____________ of individual with gene
not carried
sex hormones

19. Male Pattern Baldness
Autosomal dominant gene

20. YOUR SEX CHANGES THE EXPRESSION OF THE GENE
B is dominant for baldness
B’ is recessive for not bald
If you are MALE: If you are FEMALE:
BB = BB=
BB’ = BB’=
B’B’ = B’B’=
BALD
BALD
BALD
NOT bald
NOT bald
NOT bald

21. Will they be bald? BX By B’X Bald = B Autosomal Dominant gene
XXBB’ XyBB’
XXBB’ XyBB’
Bald dad X pure non bald mom
Girls: 100% NOT BALD Boys: 100% BALD

22. Will they be bald? B’X B’y BX Bald = B Autosomal Dominant gene
XXBB’ XyBB’
XXB’B’ XyB’B’
NOT BALD dad X NOT BALD mom (who had a bald dad)
Girls: 100% NOT BALD Boys: 50% BALD % NOT BALD

23. How are genes passed on over generations?

24. PEDIGREE CHART
Males =
Females =
Has trait =
Carrier =

26. SEX-LINKED and SEX INFLUENCED TRAITS

27. SEX DETERMINATION
XX = ___________
Xy = _________

28. Who decides? X X Mom can give X X Dad can give X or y y
Dads determine sex of babies.
If dad gives X with mom’s X = girl
If dad give y with mom’s X = boy

29. SEX CHROMOSOMES CAN CARRY OTHER GENES TOO = ___________________

30. SEX LINKED TRAITS show up in different % in males and females because they move with the sex chromosomes

31. Sex chromosomes can carry other genes
Y-LINKED GENES:
Genes carried on Y chromosome
EX: Hairy pinna
_________genes only show up in _______

32. Make a cross with a y-linked gene
Hairy ears is a
________________
________________ trait
Use ______ for hairy ears.
Use ______ for recessive normal ears.
On y chromosome so write it as ________

33. Make a cross with a y-linked geneX X
ALL GIRLS =
____________ X
ALL BOYS =
____________ yH

34. Sex chromosomes can carry other genes
X-LINKED GENES: Genes carried on the X chromosome
EX: _____________
_____________
_________________________

35. Make a cross with an X-linked gene
Hemophilia is an
________________
________________ disease
Use ______ for normal dominant blood clotting gene.
Use ______ for recessive hemophilia gene.
On X chromosome so write it as ________

36. Mother
Without hemophilia = X X
Without hemophilia = X X
With hemophilia = X X
Father
Without hemophilia = X y
With hemophilia = X y

37. Make a cross with an X-linked gene
Carrier Mom X
Normal dad XH y Xh
GIRLS
_______ = normal
_______ = look normal
but are CARRIERS
BOYS
_______ = hemophilia

38. Make a cross with an X-linked gene
Colorblindness is an
________________
________________ disease
Use ______ for normal dominant color gene
Use ______ for recessive colorblind gene.
On X chromosome so write it as ________

39. Mother
normal vision = X X
normal vision = X X
colorblind = X X
Father
normal vision = X y
colorblind = X y

40. Color blindness is sex linkedXb y XB
HOMOZYGOUS Normal Mom X
colorblind dad
GIRLS = _______________
BOYS = ________________

41. SEX LINKED TRAITS show up in different % in males and females because they move with the sex chromosomes

42. Y linked genes ________ show up in males.
X linked recessive genes appear __________ in males than females.
Females can be __________ for X linked recessive traits.
Males can _________ carriers for X linked
recessive genes. The either have trait OR are normal.

43. SEX INFLUENCED TRAITS
Genes ___________ on sex chromosomes BUT affected by ____________ of individual with gene
not carried
sex hormones

44. Male Pattern Baldness
Autosomal dominant gene

45. YOUR SEX CHANGES THE EXPRESSION OF THE GENE
B is dominant for baldness
B’ is recessive for not bald
If you are MALE: If you are FEMALE:
BB = BB=
BB’ = BB’=
B’B’ = B’B’=

46. Will they be bald? BX By B’X Bald = B Autosomal Dominant gene
Bald dad X pure non bald mom

47. Will they be bald? B’X B’y BX Bald = B Autosomal Dominant gene
NOT BALD dad X NOT BALD mom (who had a bald dad)

48. How are genes passed on over generations?

49. PEDIGREE CHART
Males =
Females =
Has trait =
Carrier =