B. b. B. b. Lesson 18 Using Punnett Squares and Pedigrees. Bb x Bb. male / sperm. X. BB. B b. Remember this?. female / eggs. B b. bb. A Punnett Square is a diagram used to identify _____________ combinations resulting from a mating.
Lesson 18 Using Punnett Squares and Pedigrees
Bb x Bb
male / sperm
female / eggs
A Punnett Square is a diagram used to identify _____________ combinations resulting from a mating.
This married couple is considering having their first baby.
The man is heterozygous for a disease. The woman is also heterozygous for the disease.
The couple comes to you for counseling. They want you to tell them are the chances they will have a healthy baby.
You know that the disease they carry is a recessive trait and that both parents are heterozygous.
Which of the above genotypes will you need to use?
Man x Woman
Man x Woman
The chance that the couple will have a baby that has the disease is _____%.
Who you are…
___________ = family record for one specific trait.
__________________ traits = genes for these traits are carried on the sex chromosomes.
The gene for Red-Green _______ _______________is carried on the ___chromosome.
Female must get ___(___) X’s to have colorblindness.
Why are most sex-linked traits carried on the X chromosome?
Male must get ___(__Y) X to have colorblindness.
Reading a Pedigree
= female without trait
= male without trait
= female with trait
= male with trait
= male carrier
= female carrier
= two parents
= three children
Analyzing a Pedigree Interactive
Another view of a pedigree…
This one is for Huntington’s Disease