This Excel file (valid 16/17 school year) is meant to be a means of collecting student data in a monohybrid cross exercise that would accompany a fundamentals of genetics lesson, such as the one found in Holt, Rinehart, and Winston's "Modern Biology." The lab is also available at http://www.central.rcs.k12.tn.us/Teachers/gullettp/documents/L-ModelingMonhybridCrosses.pdf, or http://content.ccsuvt.org/ehs/2010/08/Lab-Modeling-Monohybrid-Crosses-2011-2012.pdf (in the latter, the dominant trait is brown and recessive is white, but the spreadsheet here is set up for green being dominant, so you need to use G and g to represent the alleles). However, there is no convenient way to collect the entire class' data in any of the labs, but the class data is needed to complete the lab. That is the advantage for this spreadsheet. This lab would be appropriate for a middle school or high school biology class. Students working in pairs collect ten random genotypes from a heterozygous-heterozygous cross (this could be changed by the teacher, the file just is a convenient way to collect the data) in the exercise mentioned. Up to 13 pairs of data may be collected per tab (5 tabs included, one per class). If a valid genotype is entered by the student, the cell turns green for homozygous dominant and heterozygous genotypes and yellow for the homozygous recessive genotype. If the student makes a mistake or typo, the cell will turn red, making the error obvious. The table counts the number of each type of genotype, which the students will need to complete the lab report. Specifically, they need to calculate the probability of each genotype and phenotype and they will use the experimental data to verify the theoretical values. It is convenient for the teacher to display this using a projector. Students need access to the computer connected to the projector, so the teacher needs to be comfortable allowing students to use this computer, or at least needs to monitor the data entry by the student. I use this type of spreadsheet for class data collection in other science classes as well and find this engages students and helps to motivate them to obtain data and enter it correctly, since it is visible to the entire class.