1. Mendelian Genetics Day 2 AIM: How can we tell what traits an offspring will have? DO NOW: Worksheet (you have 5 minutes!) HOMEWORK: SpongeBob SquarePants exercises

2. A.Mendel studied many different traits of peas ex. flower color, seed pod shape, pea wrinkliness 1. All of these things are controlled by alleles What's an allele? Allele – different versions of a gene for a trait

3. Mendel learned 2 things from his experiments: 1.Genes are passed from one generation to the next 2.Genes come in (at least) pairs What made him think genes were passed down? Why did he think genes came in pairs?

4. Mendel realized that there are dominant and recessive traits Dominant - can mask or hide a recessive trait Recessive - can only be seen if there are 2 recessive alleles for the trait. Otherwise, the dominant one will hide it! *REMEMBER! Dominant does not mean better and recessive does not mean worse!*

5. P generation F 1 generation F 2 generation What’s dominant here? How do we know? What’s recessive here? How do we know?

6. Homozygous - the trait has two of the same alleles ex. YY or yy, BB or bb, AA or aa Heterozygous - the trait has two different alleles ex. Yy, Bb, Aa *NOTICE* The CAPITAL letter always comes first BUT we know there was a hiding green allele in F 1 generation! What happened?! Genotype - the pair of alleles in the DNA Phenotype - what we end up seeing in the organism

8. R Rr rR r Rr RRRr rr Rr Punnett Squares RR Rr rr

9. Punnett squares are used to figure out the outcome of a cross-breeding event Do we use Punnett squares for asexual or sexual mating? What are the alleles we use to describe a female? A male? X XYXY What are the chances we have a boy? A girl? 50% chance of a girl! 50% chance of a boy! XX XY

10. Summary How can we tell what traits an offspring will have? Make sure to use the words allele, Punnett square, genotype, and phenotype. Discuss with your neighbor! Homework: SpongeBob SquarePants Punnett Square worksheet!