Date post: | 23-Jan-2017 |
Category: |
Science |
Upload: | rosio-deleon |
View: | 290 times |
Download: | 0 times |
Assign Yourself: Sex Linked Practice
• Do Now:• Unit 2 Review 1 through 11 (yes, you may use
your homework)
Sex-Linked Inheritance
What is sex-linked inheritance?• Patterns seen when alleles for a trait are carried on
the X chromosome.
XA = X chromosome with dominant allele
Xa = X chromosome with recessive allele • Y chromosomes do NOT carry the alleles.
Processing Piece:• Draw a picture to illustrate sex-linked inheritance.• Find these on your paper:
XAXa XAY XaXa
XaY
• Label each one as a boy or girl.• Label each one as recessive or dominant trait.
What is a carrier?• A person who carries ONE allele for a recessive trait
but does NOT show the recessive trait.• Sometimes they’re shown on a pedigree like this:
= female carrier
Processing Piece:• Label the carriers.
XAXa XAY XaXa
XaY
Processing Piece:
On the pedigree below, label each person as XX or XY.
Circle X chromosomes with the recessive allele (Xa)
Processing Piece:What patterns do you notice? Who are the carriers?Who are the people affected?
What patterns are seen in sex-linked inheritance?
• Females who are carriers (heterozygous)• Males with the recessive trait
Sample Questions 1 through 3:1) Are most affected
individuals male?2) Are most carriers
female?3) Do you think this
is sex-linked inheritance?
Sample Questions 4 through 5:
4) Are most affected individuals male?5) Are most carriers female?6) Do you think this is sex-linked inheritance?
Sample Question 7A family has 2 parents, 1 son and 1 daughter. The father is colorblind (a sex-linked trait), and the mother does not carry any alleles for it. XN = normal Xn = colorblinda) What is the father’s genotype? _________b) What is the mother’s genotype? _________c) What must the daughters’ genotypes be?__________ d) What must the sons’ genotypes be? ______________e) Draw a pedigree of this family.
Sample Question 8A woman who is a carrier marries a man who has hemophilia. XN = normal Xn = hemophiliaa) Genotypes of the parents? _________ x _________ b) Draw a Punnett Square:
c) A boy who has hemophilia? ___d) A girl who is a carrier? ____e) A boy who does NOT have hemophilia? _______f) a girl who is NOT a carrier? ____
#4 on the classwork
Exit Ticket1) Which chromosome, X or Y, carries the alleles in
sex-linked inheritance?2) What are 2 patterns that are normally seen in
sex-linked inheritance?3) Draw an example of a pedigree you might see
for a sex-linked trait.
Assign Yourself: Draw and color completely (no white spots!) 2 parents and 2 dragon babies
• Do Now:• Unit 2 Review 12-23
Exit Slip
• Describe the pilot program that some schools in Kentucky participated in. Why was it started? Explain whether or not you think the program is a good idea and why. Support your response with information from the article.