Do Now Take each of the papers at the front lab table Write your name and the date on each Take out your section sheet from this week and yesterday’s sub classwork.

Does sex influence the probability of inheriting a trait? Ratio ________ = number of one kind of possible outcome/ rest of number of all possible outcomes If a trait is autosomal (a chromosome that is not X or Y), it will appear in both sexes equally . If a trait is _____________ it is a trait whose allele is located on the X chromosome. Most are recessive, but males only get one X so it will be expressed. Sex Linked

Examples of Sex Linked Traits Red-green colorblindness Male pattern Baldness Hemophilia Duchenne Muscular Dystrophy In humans, red-green colorblindness is a recessive sex-linked trait. It is found on the X chromosome, not the Y. Because males only have one X chromosome, they have a much greater chance of having red-green colorblindness. Females would need to be homozygous recessive in order to have red-green colorblindess.

What if we wanted to learn about a trait in our own families? Geneticists often prepare a ____________, a family history that shows how traits are inherited over several generations. Pedigree

Probability Practice Flower Color 705 Purple 224 white Seed color Contrasting Traits F2 Generation Results Ratio Flower Color 705 Purple 224 white Seed color 6,022 Yellow 2,001 Green Seed shape 5,474 Round 1,850 Wrinkled Pod color 428 Green 152 yellow Pod shape 822 Round 299 constricted Flower position 651 axial 207 top Plant height 787 tall 277 dwarf