1. Biology 22 Genetics and Molecular Biology Fall 2007

2. Biology 22 Fall 2007 http://homepage.smc.edu/bober_mary

3. Corn Genetics Laboratory

4. Outline of Laboratory Discussion  Introduction to the corn kernel  Collection of data for use in Chi Square analysis  Explanation of laboratory exercise Collection of data Recording of data

5.  Introduction to the Kernel

6. Variation of colors

7. Corn Kernel Color Color of aleurone masks endosperm color Only with colorless aleurone can endosperm color be determined Determined by several genes

8. Epistasis is a form of gene interaction in which one gene masks the phenotypic expression of another.

9. Genetic information regarding the corn color patterns are provided in your lab manual. The basis of these patterns.

10. Aleurone color determined by several genes (reference lab manual) R_ rr C’ CC or Cc cc P_ pp Y_ yy Purple, Dominant Colorless aleurone Colorless, color inhibitor Aleurone color in the presence of color alleles Colorless aleurone layer in presence of R No effect on aleurone layer Changes color to red Yellow Dominant White, Recessive

11.  Explanation of Corn Genetics Lab Exercise

12. Today’s lab has 3 crosses of corn (F 2 generation=2 nd filial generation)

13. Note color differneces Cross C Cross D (darker color is purple) Cross F (call purple, may look red!)

14. Collection of data: Count kernels by cross and color Select 8 ears from Cross C, D and F Count 10 rows per ear Grand Total of 240 rows to count!

15. Direction of a row of kernels Mark 10 rows

16. Record Data Record your data at your bench by cross, ear and color After you are finished record your data on the spreadsheet on the computer in the front of the lab Class data will be on my homepage http://www.homepage.smc.edu/bober_mary/

17. Bring corn to your bench and begin counting!

18. Ion Exchange Chromatography Next week lab: Ion Exchange Chromatography Read 3-25-3-33 in lab manual.