1. 4.3.2-4.3.11 Sydney Foil, Jasmine Delaine, Cameron Folmar, Stephanie Weng

2.  Alleles: one member of a pair of genes that codes for distinct traits  Genotypes: the alleles of an organism  Phenotypes: the characteristics of an organism

3.  The genotypes of offspring can determined using a monohybrid cross ◦ A monohybrid cross is a genetic cross using a single trait with two alleles (both heterozygous)

4.  Using punnett squares you can find out the ratio of phenotypes.

5.  Punnett square worksheet ◦ Work in groups of two or three

6.  Some genes can have more than just two alleles.  Although these genes can have multiple alleles individuals can only have two. ◦ Example: the gene of the A, B, AB, and O blood types. This gene contains three alleles.

7.  The alleles of I A and I B are dominant while the i is recessive. ◦ When both dominant alleles are present they form the blood group AB  Codominant alleles are pairs of alleles that both affect the phenotype when present in the heterozygote. PhenotypeGenotype AI A I A or I A i ABIAIBIAIB BI B I B or I B i Oii

8.  The mother always passes on an X chromosome to her offspring  The father can pass either an X or Y chromosome to his offspring  Some genes are present on the X chromosome and absent from the shorter Y chromosome in humans

9.  When the gene controlling the characteristic is located on the sex chromosome ◦ We associate the characteristic with gender  Sex-linked genes are carried on the X chromosome ◦ Because females have two X chromosomes, they carry two copies of the sex-linked gene while the males only carry one because they only have one X chromosome. ◦ Example: Hemophilia and color blindness

10.  Hemophilia: X H is the allele for normal blood clotting, this is dominant over the allele X h (the recessive gene which causes hemophilia)  If the mother is heterozygous, she is then a carrier of the disease and passes it on to her offspring ◦ This means the dominant and recessive alleles are present.

11.  Heterozygous: contains two different alleles ◦ Ex: Rr (one recessive, one dominant) ◦ Ex: AB blood type  Homozygous: having identical alleles for the same trait ◦ Ex: RR or rr

12.  Because a female has two X chromosomes she can carry either both recessive/dominant genes or she can have one of each (with respect to sex linked genes).  If female carriers are heterozygous they can pass it onto their offspring.

13.  Basketball: ◦ Six teams of five each ◦ Each team at a lab table ◦ Write answer on white board ◦ Get the question right first, chance to shoot

14.  "IB Biology Notes - Theoretical Genetics." IB Guides - Free International Baccalaureate Study Guides, Notes, Videos and Powerpoints. 2010. Web. 10 Feb. 2012..  "Multiple Alleles." Redirecting... Web. 10 Feb. 2012..  Pitocchelli, Jay. "Lecture Notes for Genetics." Saint Anselm College : Saint Anselm College. 2001. Web. 10 Feb. 2012..  "X and Y Chromosomes." Science Photo Library. Web. 10 Feb. 2012..