What is CODIS? Describe the four most important features of genetic markers used in this system.

Verified step by step guidance

1. Understand that CODIS stands for the Combined DNA Index System, which is a forensic DNA database used by law enforcement to identify individuals based on their genetic profiles.
2. Recognize that CODIS uses specific genetic markers called Short Tandem Repeats (STRs), which are highly variable regions in the human genome useful for distinguishing individuals.
3. Identify the four most important features of genetic markers used in CODIS: (1) High polymorphism, meaning many different alleles exist at each marker locus, increasing discrimination power; (2) Mendelian inheritance, ensuring predictable transmission from parents to offspring; (3) Independence, meaning markers are located on different chromosomes or far apart to avoid linkage; (4) Stability, indicating that the markers do not change significantly over generations or due to environmental factors.
4. Explain why each feature is critical: High polymorphism allows for unique identification, Mendelian inheritance ensures reliable genetic relationships, independence prevents correlated markers that reduce statistical power, and stability guarantees consistent results across samples and time.
5. Summarize that these features together make CODIS markers effective for forensic identification, paternity testing, and criminal investigations.

Key Concepts

CODIS (Combined DNA Index System)

CODIS is a forensic DNA database system used by law enforcement to store and compare DNA profiles. It helps identify individuals by matching DNA samples from crime scenes with known profiles, facilitating criminal investigations and justice.

Genetic Markers in CODIS

Genetic markers in CODIS are specific DNA sequences used to create unique profiles. These markers are typically short tandem repeats (STRs), which vary greatly among individuals, making them ideal for identification purposes.

Key Features of Genetic Markers in CODIS

The four important features of genetic markers in CODIS are high polymorphism (many alleles), reproducibility (consistent results), ease of analysis (simple lab techniques), and independence (markers are unlinked to avoid inheritance bias). These ensure accurate and reliable identification.