1. Concept : Mendelian Inheritance Learning Essential Question: Who is Mendel and what are his laws? Explain the relationship between traits and heredity Explain the difference between dominant and recessive traits.

2. Terms to know Heredity/Inheritance: the passing of traits from one generation to another Traits: physical characteristics. Passed on through DNA from parents to offspring through sexual reproduction, Dominant Trait: a trait that is always expressed and represented by a capital letter .Example: B for brown hair Recessive Trait: a trait that is only expressed if two recessive alleles are present, represented by a lower case letter. Example: b for blonde hair 3. Term to know! Genotype- an organisms inherited combination of alleles Phenotype- an organisms inherited appearance Genes- a segment of DNA that carries hereditary instructions and is passed from parent to offspring Alleles- multiple forms of the same geneTrue-breeding- all of the offspring will have the same trait as the parent when self-pollinate First-generation- the very first set of offspring from two parents 4. Have you heard about clones, designer babies and animals that grow human body pats? These are developments of the science of Genetics. Heredity is the passing of traits from one generation to the next. The study of heredity is called genetics. Genes are located in the nucleus of each of your cells Father of Modern Genetics. Austrian monk born in 1822 Mendel studied the inheritance of traits in pea plants and develop the laws of inheritance. Mendel used observation to study thousands of pea plants over 7 years. He wanted to understand how characteristics were passed from one generation to the next. 5. The father of genetics While working in his garden, Mendel wondered why different pea plants grew tall, while others were short. some had green seeds, others yellow. He called all these characteristics traits. Mendel was responsible for figuring out that each plant carried two sets of instructions for each characteristic (one from the mom and one from the dad). 6. Gregor Mendel Discoveries Mendel discovered the principles of heredity and the passing on of characteristics (traits) from parents to offspringAfter preforming experiments with pea plants. Mendel found that the plants' offspring retained traits of the parents 7. In flowering plants, male reproductive cells called pollen are created and stored on the anther. The female reproductive cells are created and stored in the ovary. When pollen touches the stigma, it falls through a tube and into the ovary. Here, it combines with female reproductive cells which begin to grow into seeds. Stigma: Receives pollenOvary: Female reproductive cellsAnther: Creates pollen-male reproductive cellsSeeds 8. Why Mendel choose pea plants? I choose pea plants because they reproduce quickly, produces several generations, can be artificially cross-pollinated and self-pollinate. Pea plants are usually self-pollinating meaning they can pollinate themselves, even when they are alone. I was able to grow true breeding plants and determine the traits for each generation Cross-pollination When the pollen from one plant fertilizes the ovule of a flower on a different plantSelf-pollination Has both female and male structures, so pollen from one flower can fertilize the ovule of the same flower 9. Some of the Traits studied in pea plants Mendel investigated seven traits in pea plants. (stem length, pod shape, seed shape, seed color, heigth,Plant HeightTallShort Flower colorPurple petalsWhite petalsSeed ColorGreenYellowPod ShapeSmoothPinchedPod colorGreen Yellow Seed ShapeWrinkledRound 10. How Mendel began his experiments Mendel developed a method to crosspollinate plants by moving the pollen from one plant to the pistil of another. Mendel handpollinated flowers using a paintbrush He snipped the stamens of each flower to prevent selfpollination, then he covered each flower with a cloth bag and finally he traced traits through the several generationsPollen transferredParental GenerationFirst Generation offspring 11. Mendel crossed his pea plantsThe first generation (F1) of plants all had purple flowers. Where did the white color go?(pp)Purple Parent (PP)White Parent Mendel crossed flowers that were true-breeding for each characteristic. He crossed a purple (PP) flowered plant with a white (pp) flowered plant. (Parent Generation)(Pp)(Pp)(Pp)(Pp) 12. Mendel and His Peas In the second generation (F2) he had 3 purple flowered plants, and 1 white flowered plant.Purple Parent (Pp)Purple Parent (Pp) Mendel took two of his first generation (F1 x F1) purple flowered plants and crossed them together. 13. Mendel noticed in the first generation, all of the white flowers seemed to disappear. He called this a recessive trait. The white color faded into the background at first. It showed up in the next generation when he pollinated the flowers. The color (purple) that seemed to mask over the recessive color was named the dominant trait. 14. Dominant Represented by a capital letter this allele makes the trait show, it can cover up or mask other alleles Gene that always shows Dominant trait-Strongest traitBlack hair is dominant traitRecessive Gene that only shows if there is no dominant gene present Represented by a lower case letter this allele seems to disappear when paired with a dominant alleleBlonde hair is a recessive trait