Why in NEWS
Following the Air India Boeing 787 Dreamliner crash in Ahmedabad, severely damaged human remains were identified using DNA analysis — now the gold standard in disaster victim identification.
Key Terms Explained
| Term | Meaning |
|---|---|
| DNA (Deoxyribonucleic Acid) | Hereditary material in nearly every human cell that carries genetic instructions |
| DNA Profiling | Scientific process of identifying individuals by examining unique regions in their DNA |
| STR (Short Tandem Repeats) | Short repeated sequences in DNA that differ between individuals and are used in forensic analysis |
| mtDNA (Mitochondrial DNA) | DNA found in cell mitochondria, inherited from the mother, useful in identifying degraded remains |
| Y-Chromosome | A sex chromosome passed from father to son, used to trace paternal lineage |
| SNP (Single Nucleotide Polymorphism) | A single base pair variation in DNA, used when DNA is highly degraded |
| Disaster Victim Identification (DVI) | A process of identifying individuals killed in mass fatality events using various methods including DNA |
What is DNA Analysis and Its Application in Disaster Victim Identification?
| Aspect | Details |
|---|---|
| Definition | DNA analysis involves examining genetic material to identify individuals, trace relationships, or detect genetic traits |
| Significance | DNA profiling is highly accurate due to individual-specific variations, especially in STRs |
| Nature of DNA | Found in the nucleus of eukaryotic cells and cytoplasm of prokaryotic cells; 99.9% of DNA is common to all humans, but 0.1% makes each individual unique |
| Importance in Disasters | Helps identify remains when visual recognition, fingerprints, or dental records are unviable due to damage or decomposition |
Major DNA Analysis Techniques Used in Mass Fatality Events
| Technique | Features | When Used |
|---|---|---|
| STR Analysis | Most common forensic method, analyzes short repeating sequences in nuclear DNA | High accuracy unless DNA is heavily degraded |
| Mitochondrial DNA (mtDNA) Analysis | Uses maternally inherited DNA present in many copies per cell | Suitable for degraded remains or when only maternal relatives are available |
| Y-Chromosome STR Analysis | Targets Y-chromosome passed from father to son | Effective for identifying male victims via paternal male relatives |
| SNP Analysis | Identifies variations at single base pairs in the genome | Used when DNA is highly degraded and limited material is available |
In a Nutshell
Memory Code
“Some Men Yell Softly”
S – STR Analysis
M – mtDNA Analysis
Y – Y-Chromosome Analysis
S – SNP Analysis
Prelims Practice Questions
- Which of the following DNA analysis methods is best suited when remains are heavily degraded?
A. STR analysis
B. Mitochondrial DNA analysis
C. Fingerprint analysis
D. Y-chromosome analysis - What percentage of human DNA is typically identical across individuals?
A. 50%
B. 75%
C. 90%
D. 99.9% - What is a key advantage of mitochondrial DNA in forensic use?
A. Paternally inherited
B. Single copy per cell
C. Survives better in degraded samples
D. Used only in plants
Mains Practice Questions
- Discuss the role of DNA analysis in disaster victim identification and explain the relevance of different DNA techniques. (GS 3)
- How do advances in DNA profiling help ensure justice and humanitarian relief during mass casualty events? (GS 3)
Prelims Answer Key and Explanations
| Q | Ans | Explanation |
|---|---|---|
| 1 | B | mtDNA analysis is effective when nuclear DNA is degraded due to its multiple copies per cell |
| 2 | D | 99.9% of human DNA is identical; 0.1% contains unique variations |
| 3 | C | mtDNA exists in multiple copies and is more likely to survive damage than nuclear DNA |
