This document provides an introduction and review of genetics concepts for students. It includes definitions of key genetics vocabulary. It discusses Mendel's experiments with pea plants and the principles he developed including dominant and recessive traits, inheritance of traits from parents, and using Punnett squares to determine probability of offspring traits. It provides examples of problems involving incomplete dominance and probability. It assigns homework to complete practice problems and review class notes, and notifies students there is no homework over spring break.

1. HOMEWORK FROM LAST CLASS: Complete the Genetics Practice Problems worksheet Read over class notes and check out the class blog: http://msoonscience.blogspot.com/

2. INTRODUCTION TO GENETICS - REVIEW

3. Remember me? Who am I? I’m Gregor Mendel, the “Father of Genetics”! I’m an Austrian monk who studied the inheritance of traits (characteristics) in pea plants. Pea 

4. VOCABULARY REVIEW

5. VOCABULARY REVIEW Match the following vocabulary words to the correct number. _________ trait A place on a chromosome that gives information for a protein _________ recessive 2. A physical feature resulting from a genotype _________ heredity 3. A form of a gene _________ genotype 4. The combination of alleles for a trait; represented by 2 letters _________ phenotype 5. The study of heredity _________ dominant 6. The passing of traits from parent to offspring _________ gene 7. An allele that gets masked so it cannot be expressed (unless it is paired with its counterpart allele) _________ allele 8. A characteristic or feature of an organism that can be passed from parent to offspring _________ genetics 9. An allele that masks another, and is always expressed in the phenotype

6. VOCABULARY REVIEW - ANSWERS Match the following vocabulary words to the correct number. 8 trait A place on a chromosome that gives information for a protein 7 recessive 2. A physical feature resulting from a genotype 6 heredity 3. A form of a gene 4 genotype 4. The combination of alleles for a trait; represented by 2 letters 2 phenotype 5. The study of heredity 9 dominant 6. The passing of traits from parent to offspring 1 gene 7. An allele that gets masked so it cannot be expressed (unless it is paired with its counterpart allele) 3 allele 8. A characteristic or feature of an organism that can be passed from parent to offspring 5 genetics 9. An allele that masks another, and is always expressed in the phenotype

7. INCOMPLETE DOMINANCE Genes are not always dominant or recessive —in some gene pairs, the genes are neither dominant nor recessive. Instead, these genes show incomplete dominance Incomplete dominance: neither gene in a gene pair masks the other  The traits carried by the 2 genes are blended

8. INCOMPLETE DOMINANCE Neither the red gene (R) nor the white gene (W) is dominant. When the 2 genes are present in the same plant, a pink flower results. Both R and W are used (capital letters) because neither the red gene nor the white gene is dominant over the other. White Red

9. GENETIC PRINCIPLES 1) Traits are passed on from one generation of organisms to the next generation. 2) The traits of an organism are controlled by genes. 3) Organisms inherit genes in pairs, one gene from each parent. Parent generation (P1) 1 st filial generation (F1) 2 nd filial generation (F2)

10. GENETIC PRINCIPLES 4) Some genes are dominant , whereas other genes are recessive. T > t 5) Dominant genes hide recessive genes when both are inherited by an organism. 6) Some genes are neither dominant nor recessive . These genes show incomplete dominance.

11. PROBABILITY What is probability ? The possibility, or likelihood, that a particular event will take place. Example: If you toss a coin, what are the chances that the coin will land heads up ? 50% (either heads or tails) The results of one event do not affect the results of the next.  Previous events do not affect future outcomes

12. PROBABILITY F1 cross (Bb x Bb) What percentage of offspring are purebred purple ? 25% (1/4) What percentage of offspring are hybrid purple ? 50% (2/4) What percentage of offspring are purebred white ? 25% (1/4)

13. PROBABILITY F1 cross (Bb x Bb) What percentage of offspring have the same genotype as the parents? 50% (2/4) What percentage of offspring have the same phenotype as the parents? 75% (3/4)

14. ACTIVITY! Paint your paper maché eggs and sperm!

15. INSTRUCTIONS 1) Find your pair’s egg or sperm. 2) Put newspaper down on your lab bench. 3) Paint your egg or sperm— get creative! 4) Place your painted egg or sperm on top of newspaper on the back table dry. I will hang the eggs and sperm in the classroom when they are dry!

16. GREGOR MENDEL’S PUNNETT SQUARES http://www.youtube.com/watch?v=d4izVAkhMPQ&feature=player_embedded

17. HOMEWORK FOR NEXT CLASS: Take a break! No homework over Spring Break! 

18. WORKS CITED Images taken from the following sources: http://elleseconomy.com/ http://mcclungsworld.com/2009/09/24/plants-squares-and-stuff/ http://www.life123.com/parenting/education/probability-statistics/probability-problems.shtml http://smabiology.blogspot.com/2008_11_01_archive.html http://www.graphicshunt.com/health/images/chromosome-885.htm