2. 1.My somatic cells have ____ (#) chromosomes or __n and they are _______ 2.My sperm/egg (pick one) cells have ____ chromosomes or __n and they are _______ 3.I got these chromosomes from: 4.Each sex cell is genetically unique because: 5.Two purposes of Meiosis: 1.______________________2. _______________ Review…

3. Heredity Gregor Mendel: Augustinian Monk, 1822-1884 (Watch this 2:35 Video)(Watch this 2:35 Video) Genetic studies on pea plants Discovered dominant and recessive traits in all organisms that are randomly given to offspring.

4. Important things Mendel learned –SEGREGATION - genes occur in pairs (one from each homologous chromosome), which separate during meiosis to form gametes with 1 copy of each gene –INDEPENDENT ASSORTMENT – the 23 chromosomes you inherit from each parent are randomly selected [For instance: 10 of them might be from your grandpa and 13 from grandma] –DOMINANCE - some genes can block others from being seen

5. Alleles

6. Dominant vs. Recessive + = + + = =

7. Ex: Tall is dominant to short GenotypePhenotype TT_________ Tt_________ tt_________

8. tt CCbb Xh YXh YXh YXh Y Ee dd Mm Genotype

9. Short Curly Hair Blonde hair Receding Hair Line Detached earlobe Dimples Melanin Produced Phenotype

10. Heterozygous Homozygous TtTt BbBb GgGg NnNn AaAa DdDd TTTT bbbb gggg NNNN aaaa dddd

11. TtTt BbBb GgGg NnNn AaAa DdDd TTTT bbbb gggg NNNN aaaa dddd Hybrid Purebred/ True breeding

12. Examples TT_________ Tt_________ tt_________

13. …So what can we do with all this vocab??? Is there an easier way to understand this?? Reginald Punnett sure thinks so! A Punnett Square is a device used to predict the results of a cross.

14. EGGS (from who?) Sperm (from who?) T We are going to figure out the offspring if we were to cross a true Tall Pea Plant with a true short pea plant! T t t x TT x tt

15. EGGS (from who?) Sperm (from who?) T TT x tt T t T t T T T t t TT T t t t t t t t

16. You just did exactly what Mendel DID!! TT t t How Many… Genotype TT= Tt= tt= Ratio= Phenotype Tall= Short= Ratio=

17. Your Turn! Show a Punnett Square and Analysis of two tall heterozygous plants being crossed Remember –(show the egg & sperm) –Fill in the punnett square –ANALYZE

18. A Heterozygous Cross How Many… Genotype TT= Tt= tt= Ratio= Phenotype Tall= Short= Ratio=

19. Punnett Square Black fur is dominant to white fur in rabbits. If a heterozygous black rabbit mates with a white rabbit, what is the chance they will have a white bunny?

20. Punnett Square Practice The color red in roses is dominant to yellow. If a homozygous red rose is crossed with a heterozygous red rose, what is the chance a yellow rose will be produced.

21. Big Punnett Squares Example If having brown eyes (B) is dominant to blue eyes (b), then what is the phenotypic ratio of the offspring when crossing a heterozygous brown eye father with a blue eyed mother?

22. If two plants were crossed and they had 52 offspring that were white and 58 that were red, what is the ratio of red to whiteIf two plants were crossed and they had 52 offspring that were white and 58 that were red, what is the ratio of red to white Perform a Punnett Square between a man and woman to determine the chances of having a baby girlPerform a Punnett Square between a man and woman to determine the chances of having a baby girl