Block Day - Wrapping Up Heredity

Today we applied the Chi-Square equation to some practice problems.  On our test you would be given the equation and a copy of the probability table.  You would be responsible for calculating the Expected Values, Calculating the Chi-Square value, determining degrees of freedom, interpreting the probability table and determining if your hypothesis should be accepted or rejected.

How to read the probability table: Once you have determined your chi-square value you must calculate degrees of freedom.  This is simply the number of classes (for example, there are 4 classes for blood type, O, A, B, and AB) and subtract 1 (for the blood type example the degrees of freedom is 4-1 = 3).  Then look at that column in the probability table.  In science experiments we only use the 0.05 probability row.  Compare the chi-square value to the number in the table.  If chi-square value is BELOW the number then we ACCEPT our hypothesis, if the chi-square value is ABOVE the number then we REJECT our hypothesis.  The interpretation of the table is that if our chi-square value is above this number then there is a 95% likelihood that our deviation from expected is due to something other than chance.

The second half of class was spent going over 15.4 which discusses chromosomal abnormalities.  Use your textbook to review these concepts if you are having difficulty with them.  Below is a picture from the power point that shows the rates of various chromosomal abnormalities.

LIST OF TOPICS YOU SHOULD KNOW FOR TOMORROW's TEST:

monohybrid crosses

incomplete dominance crosses

codominance crosses

multiple alleles (blood types)

pedigrees

dihybrid crosses

pleiotropy

epistasis

polygenic traits

linked genes

creating linkage maps from crossover data

sex-linkage

non-disjunction errors

deletion, duplication, inversion, translocation errors