Warm ups: Match the following terms to their definitions 1. genetics a. form of a gene 2. trait b. process of reduction division 3. hybrid c. specific characteristic 4. gene d. produced by crossing parents with different alleles 5. allele e. containing a single set of chromosomes 6. Punnett square f. factor that controls traits 7. haploid h. diagram showing possible gene combinations 8. meiosis i. branch of biology that studies heredity

How to track traits in a family through the generations!

What is a Pedigree? 1. A pedigree is a chart of the genetic history of a family over several generations. - Can be used to determine genotypes of family members. - Can be used to help predict probability of future generations expressing certain traits. 2. Important tool for genetic counselors - they will use pedigree charts to help determine the distribution of a disease in an affected family

Constructing a Pedigree: What do all these symbols mean? Male - square Female – circle - unshaded – does not show trait - shaded – trait - half shaded – carries the trait - diagon slash = deceased

Connecting Pedigree Symbols Married Couple (mating) - Straight line depicts parents Children are connected under the parents with a vertical line Siblings are connected by lines a horizontal under the parents Oldest child  Youngest child

Connecting Pedigree Symbols Fraternal twins Identical twins

Organizing the pedigree chart A pedigree chart of a family showing 20 individuals Generations are identified by Roman numerals I II III IV

Organizing the pedigree chart I II III IV Married couple Their 5 children Married couple Their 3 children Married couple Their 5 children

A B G F E D C M L K J I H R Q P O U T S 1.List the people in the family that have the trait of blond hair. 2.List all the females in the family. 3.What relationship is person O to H? What relationship is person B to H? Answers; 1.E, Q, R 2.B, D, E, I, K, M, P, Q, R 3.O is H’s son B is H’s mom

Organizing the pedigree chart Scientists identify individuals in each generation by Arabic numerals numbered from the left and the Therefore the affected individuals are II3, IV2 and IV3(instead of letters) I II III IV

1.How many generations is this pedigree showing? 2.List the people in the family that have the trait of blue eyes. 3.List all the males in the family. 4.What relationship is person III2 toII3? What relationship is person I1 to II3? Answers; 1.3 generations 2.I1, III1 3.I1, II1, II3, 4.III2 is II3’s daughter; I1 is II3’s dad

Exit slip: Answer the following questions 1. What is a pedigree? 2. What is the symbol for a male who has the trait? 3. What is the symbol for a female who doesn’t have the trait? 4. If a circle is half shaded in, what does that mean?