This document introduces genetics concepts discovered by Gregor Mendel, including: 1) Genes determine inheritance and are passed from parents to offspring. Genes exist in variants called alleles that can be dominant or recessive. 2) When organisms reproduce sexually, each parent contributes one of each gene which segregate into gametes independently. 3) Mendel's experiments with pea plants showed dominant traits fully expressed in the F1 generation but segregated in a 9:3:3:1 ratio in the F2 due to independent assortment of alleles.

1. Introduction to Genetics

2. Gregor Mendel

3. Genes and DominanceP generationF1 generationHybrids

4. Genes and DominanceThe F1 generation had the character of only of the parentsMendel drew two conclusionsBiological inheritance is determined by factors that are passed from generation to the nextThe principle of dominance GenesAlleles

5. Segregation

6. Genetics and ProbabilityThe likelihood that a particular event will occur is called probabilityThe principles of probability can be used to predict the outcomes of genetic crosses

7. Punnett SquaresPunnett SquaresHomozygousHeterozygousPhenotypesGenotypes

8. Probability and Segregation

9. The Two Factor Cross: F1Two different genes passing from generation to anotherFirst, Mendel crossed tree-breeding plants (RRYY x rryy)All of the F1 offspring produced the dominant genes

10. The Two Factor Cross: F2Mendel knew that all the F1 plants were heterozygous for both genesThe F2 generation shows how alleles segregateSince the alleles for both genes segregated independently of each other (independent assortment), the ratio was 9:3:3:1The principle of independent assortment states that genes for different traits can segregate independently during the formation of gametes. Independent assortment helps account for the many genetic variations observed in plants, animals, and other organisms

11. Summary of Mendel’s Principles

12. Summary of Mendel’s PrinciplesThe inheritance of biological characteristics is determined by individual units known as genes. Genes are passed from parents to their offspringIn cases in which two or more alleles of the gene for a single trait exist, some forms of the gene may be dominant and others may be recessiveIn most sexually reproducing organisms, each adult has two copies of each gene - one from each parent. These gens are segregated from each other when gametes are formedThe alleles for different genes usually segregate independently of one another

13. Incomplete Dominance

14. Codominance

15. Multiple Alleles

16. Polygenic Traits

17. Genetics and the Environment