1. Mendel THE FATHER OF THE GENETICS

2. Do Now Look at your parents. What color hair do they have? What color eyes do they have? What shape of ears do they have? Now look at you. Which “traits” did you get from each of your parents? Which traits did your brothers or sisters get? Why don’t you look EXACTLY like one of you parents?

3. Next…. Taste Lab!!!!

4. Vocabulary ◦Heredity – passing of traits from one parent to the next ◦Genetics – the study of how traits are passed from parents to offspring ◦Dominant trait – a genetic factor that blocks the appearance of another trait ◦Recessive trait – A genetic factor that is blocked by the presence of a dominant trait.

5. Vocabulary Cont. ◦Gene – a section on a chromosome that has genetic information ◦Allele – the different forms of a gene ◦Phenotype – how a trait appears to the observer ◦Genotype – the two alleles that control the phenotype of a trait

6. Mendel, the father of genetics ◦Born Johann Gregor Mendel, in what is now the Czech Republic. ◦Was a poor farmer, but an awesome students ◦His parents spent all of their money on his education, but when dad got injured, Mendel had to find other ways to get his education ◦Became a monk (out of necessity) and went to school for free.

7. What is up with Mendel? ◦We now credit this monk as the father of Modern genetics ◦You’all, as sixth graders, know more about modern genetics than he did when he finished his work. ◦You all know that there’s DNA, and our traits reside on that DNA ◦You also have seen how cells divide, and he didn’t know things like that.

8. Well, what did he discover? ◦Mendel used the humble pea plant to help him discover and write his three major laws ◦Law of segregation – Each organism has two copies of one allele, and that they pass one copy randomly to their offspring. ◦Law of independent assortment – Separate genes of separate traits are passed down independently to the next generation. ◦Law of Dominance – That recessive alleles will always be masked by dominant alleles.

9. Whoa Whoa Whoa, What does that mean? ◦Law of segregation ◦States that each organism has two copies of one allele, and that they pass one copy randomly to their offspring. ◦Remember Allele is a trait on a gene that is expressed ◦And remember a gene is genetic information on a chromosome

10. Think of it like a bracelet ◦This group of bracelets is all of the DNA in one of your cells ◦One of the bracelets is a chromosome in your cell’s nucleus ◦The beads on the bracelet are the genes in your chromosomes ◦The alleles are the code for what color, material, or size beads they are.

11. Law of independent assortment ◦This states that each gene is passed on independently of each other ◦If we look at Mendel’s peas that he worked with, there are many traits he saw, for instance ◦Pea color ◦Flower color ◦Pea shape ◦Pea pod shape ◦Etc. ◦Each of these physical traits were passed on to its offspring without influencing another trait

12. He studied these peas for 8+ years! (Talk about Dead!) ◦But he got really good at his observations. ◦He found that there were even ways to predict what type of peas he would have after he crossed offspring from pure bred parents (he could predict the ratio of what the grandkids would look like) ◦That ratio, for each allele was 3:1, as shown in the Punnett square to the right

13. Third Law ◦Law of Dominance ◦A dominant allele always masks a recessive allele ◦If a rabbit that’s dominant for black fur mates with a rabbit that’s recessive for white fur what Will the baby rabbit look like? ◦The baby will be Black, not gray

14. One more thing!!!! ◦We’ll be talking a lot about genotypes and phenotypes in this unit. You’ll need to know the difference between them ◦A genotype is the two alleles that control the phenotype ◦The phenotype is what we observe the organism to look like / sound like / smell like / taste like / Etc.

15. Exit Slip! ◦How many laws did Mendel publish? ◦If a pea with dominant purple flowers is crossed with another pea with recessive white flower, what color will the flower be? ◦Will the flower color for the above question affect the shape of the pea seed? What law tells us this? ◦What is the difference between phenotype and genotype?