Question

Forensics/genetics help! Thanks!

1) In the gel pictured below, lane 1 is from a crime scene, the other lanes are from suspects. a. Which is the only suspect that is not excluded from the crime? b. If all alleles possible for that locus are represented, what is the probability that the non-excluded suspect matches the crime scene sample by chance? Explain the banding pattern for the individual in lane 7. 3 6 c. |-- (A 2pts, b 4pts, c 4pts) 2) The gel below shows two different loci run on a single gel. Using the gel pictured below, tell which suspect is innocent of any crime. If all possible alleles for each locus are pictured in the gel, what is the probability that the other suspect did not commit the crime? (Lanes 1-4 locus 1, lanes 5-8 locus 2; lanes 1 & 5: blood sample from crime scene, lanes 2 & 6: victim, lanes 3 & 7: suspect 1, lanes 4 & 8: suspect 2) (5 points) 6 8 3) Gené et al. (1998) examined four of the microsatellite loci used by the FBI in Catalonia (NE Spain) They found 8 alleles for D3S1358, 10 alleles for D8S1179,13 alleles for D18S51, and 11 alleles for D19S253. If a Catalonian man matched DNA taken from a crime scene, what is the probability (if the evidence was not planted or contaminated) that he was never at the crime scene? (5 points)

Answer 1

Ans-1 A- the suspect in lane 4 is not excluded from crime because both the locus are in match with the locus found on crime scene so it is not excluded.

B- the probability of the non excluded suspect of being by chance is negligible because no other suspect matches the reference pattern so there are equal to zero chance of by chance.

C- the individual in lane 7 has pattern for a totally different gene which is not present on crime scene. The band appear of a different locus, perhaps of a different gene so the suspect may be thought to be innocent or not include in crime.