Blackett Family DNA Activity 2

DNA Profile of a "Missing Person"

In this activity you will assume the role of a forensic DNA analyst. Your task will be to determine the DNA profile for a "missing person" from the analysis of close family members. DNA analysts often have to recreate genotypes for those whose DNA is not readily available for analysis. A recent case of great national interest was the identification of the remains of the Vietnam soldier who had been interred in the Tomb of the Unknown Soldier.

Here are your options:

  • Go immediately to the questions below and interpret the data you have already collected.
  • Review the principles of genetics needed for this activity
  • Skip the data collection, and Use the data that we have collected for you for Question #1.
  • Download a worksheet for this activity in PDF format with the data that we have collected for you for Question #1.
  • Completed data for Buddy, Dick, Marilyn, and Janet in Table or pdf format for Question #2.
1. What is Steve's Genotype?
In our activity, we obtained data for Karen and her three daughters, Tiffany, Melissa, and Amanda. Bob Blackett has not yet had the opportunity to test the DNA of Steve, so Steve can play the role of the "missing person" in our activity. Determine Steve's genotype at the 13 CODIS STR loci. Indicate whether there is an unambigous genotype where both alleles are know, or some uncertainty about both paternal alleles.
2. What are the Genotypes of Bud and Louise?
What happens when we have two missing people? Human geneticists are often asked to determine if adult children in the same family all have the same biological parents. Demonstrate that all of the genetic information for the children of Bud and Louise is consistent with all 4 having the same two parents.

Introduction : Overview | STR P | CODIS | Analysis | Inheritance | Frequency Calc.

Activities : Pedigree | Collect data | Paternity testing | Missing person | RCMP freq. calc.

The Biology Project
University of Arizona
October 27, 2000
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