Warm-Up #7 2/29/12 Define the following in your own words: 1) Incomplete Dominance 2) Codominance 3)Independent Assortment 4) What two factors affect your characteristics? 5)What are the offspring possibilities if Dad has IAIA blood and Mom has IAIB blood?

Dihybrid Cross of WwDd x WwDd

Quiz Today! You have 5 to 10 minutes to look over the highlighted portions of the notes After the quiz, turn it in up front and grab today’s notes Write down the essential questions

Warm-Up # 8 3/1/12 Mike has IAi blood and his wife has ii blood, what type of blood can there offspring have? Cindy has IAIB blood and her husband has IAIB blood, what type of blood can their children have? Kerri has IBi Blood, what is his phenotype? Jim has A blood, what can his genotype be?

Pedigrees and Sex-linked Traits Chapters 14-1 and 14-2 Mendelian Genetics Unit 8

What Are We Learning? Essential Question: Objectives: Identify the types of human chromosomes in a karyotype Explain how sex is determined Explain how pedigrees are used to study human traits Describe examples of the inheritance of human traits Explain how small changes in DNA cause genetic disorders Essential Question: What is the purpose of a pedigree?

Human Traits Human traits are inherited according to the same principles Mendel discovered with the garden peas. Biologist must identify an inherited trait controlled by a SINGLE gene. They study how the trait is passed from one generation to the next.

Common Inherited Traits

Pedigree Chart that shows how traits controlled by one gene are inherited in a family tree.

Pedigree Rules and Symbols Males = Females = A marriage line = Children (first to last) = (connected to parents with vertical line)

Symbols and Shapes A shaded square or circle indicates the person expresses the trait. A square or circle not shaded indicates the person does not express the trait. A square or circle half shaded indicates the person is a carrier for the trait.

This pedigree shows the inheritance of attached ear lobes. Which parent has attached ear lobes? 2. How many children do the parents have? 3. Which child has attached ear lobes? 4. Which child is married? 5. Does this child’s spouse have attached ear lobes? 6. Do any of this child’s children have attached ear lobes?

Answers Father Three Oldest Daughter (II-1) Youngest Son (II-3) No Yes (III-2)

Hint Hint...Wink Wink If the majority are filled in the trait is Dominant (AA/Aa) If not many are filled in it is recessive (aa).

Sex Chromosomes Every egg has one X sex chromosome. Half of all sperm have an X sex chromosome and half have a Y sex chromosome. Females XX Males XY

Sex Chromosomes Gene located on a sex chromosome are called sex-linked Most of these sex-linked genes are on the X chromosome Males only get a “single-dose” (only have one X) What is on the X is what shows! Females get two “doses” of the gene They follow rules of dominance

R = red eyes r = white eyes Pure Red eyed Female X White eyed Male Genotype 2:2 Phenotype 2:2

Sex-linked Disorders More Common in Males Males only receive 1 X-chromosome!!! X-chromosome carries the gene. Examples: Hemophilia, Muscular dystrophy, Color blindness: 1 in 10 males are color blind

Practice! On a separate sheet of paper, build a pedigree for any disease. Your pedigree must include three generations. The 1st generation are the Grandparents They have 5 kids (you pick ratio) =2nd Generation They have 10 Grandkids, you pick who gets married and how many kids they have. You must include carriers and those infected by coloring them. Name the people in your pedigree and make a key! Give your pedigree a title

Three Generation Pedigree for Heart Disease KEY