At a crime scene a blood sample was found and investigated using gel electrophoresis. Based on the gel, the blood at the crime scene belongs to which of the suspects?

• A. Jenny
• B. Bob
• C. Mike
• D. Lisa
• E. The blood at the crime scene does not belong to any of these suspects.

Answer: (C)

Verified step by step guidance

1. Understand that gel electrophoresis is a technique used to separate DNA fragments based on their size. The DNA fragments move through a gel when an electric current is applied, with smaller fragments moving faster and further than larger ones.
2. Observe the gel electrophoresis image provided. Each column represents the DNA banding pattern of a different individual: the blood sample from the crime scene, Jenny, Bob, Mike, and Lisa.
3. Compare the banding pattern of the blood sample (first column) with each of the suspects' banding patterns (columns 2 to 5). Look for a pattern that matches exactly in terms of the number of bands and their positions.
4. Focus on the column labeled 'Mike' and compare it with the 'Blood Sample' column. Check if the number and position of the bands in Mike's column match those in the blood sample column.
5. Conclude that if the banding pattern of the blood sample matches exactly with Mike's banding pattern, then the blood at the crime scene belongs to Mike.