|
For example, with the above cross tTHhDd x tTHhdd usually the main question is "what are the odds of getting tt hh dd offspring?" FOIL the "t" locus to get tt, tT, Tt, TT. Out of the 4 outcomes, 1 is "tt." Your odds are 1/4 so far. FOIL the "h" locus to get HH, Hh, hH, hh. Out of the 4 outcomes, 1 is "hh." Your odds are 1/4th (from before) times 1/4th (from this locus) for a total of 1/16th. FOIL the "d" locus to get Dd, Dd, dd, dd. Of the 4 outcomes, 2 are "dd." Multiply again: 1/16th times 2/4ths = 2/64ths which simplifies to 1/32. The odds of getting tt hh dd from that cross are 1 in 32 for each offspring. If you count the squares in the grid created earlier, you'll find the same answer: there are 32 squares, only one of them is tt hh dd. This technique is a real time saver, and with a bit of practice, you can do it in your head. There are also online genetics calculators that will give you the results, but it's helpful to understand where these results come from before using the calculator. It can also be handy to have a general idea of the expected results without having to run to the computer.
Review:[Home] [Digital Editions] [CMG Genetics Tutorial] [Serpwidgets Genetics] [Links] [Contact] Cornsnake Morph Guide is a registered trademark of Charles Pritzel All content on this site is copyright © 2004-2012, Charles Pritzel |