LAB HANDOUT
Section I
Tell you how to do the Chi-square method, we will need in total 10 Chi squares. (5 tables, in the five tables we have 1 chi-square for “Your own results”, then another for your “Total class results”, do this do every table)
Perform a X2 analysis of YOUR DATA and the CLASS DATA
Section II
Information about the life cycle of corn Zea mays
Section III
We were given 5 corns, with corn ears displaying a variety of phenotypic ratios
We need to develop a Hypothesis and test the ratio statistically
We were given a set of 5 ears
Ear #1: Purple and Yellow
Ear #2: Purple and Yellow
Ear #3: Purple and starchy, yellow and sweet
Ear #4: Purple and starchy, Purple and sweet, Yellow and starchy, Yellow and sweet
Ear #5: Purple and Yellow
Our goal was to count the phenotypes of the kernels of each ear of corn.
We recorded our results and constructed a table with the information needed.
We have to postulate a ratio for each ear that seems to fit the observed data.
For each cross done, start with the parental generation, illustrate the crosses that have been performed to produce these F2 progeny. Use the following symbols for different alleles:
Allele Phenotypic expression
R Purple aleurone colour
r Yellow aleurone colour
Su Starchy endosperm texture
su Sweet endosperm texture
c Purple aleurone colour
C inhibited colour (—–> yellow)
* fill in the 5 answer sheets (one for each type of ear)
LAB REPORT
The lab report should include 2 of the following topics:
Aggregation in pollen grains
Genetics of corn kernels
Where appropriate include:
A complete data set
Hypothesis and the rationale that lead you to them
A statistical analysis of the data
The genetic basis for observed phenotypic ratios
Genetic inferences you can derive (i.e: what phenotype is dominant? What are the genotypes fo the parents?…)
A discussion of the role of Mendel’s laws, gene interaction, sources of errors…
Crosses that would yield the observed results, symbols for the genes, Punnett squares…)
NEED to have an introduction, methods, results, discussion section.
