Dna and Functions

DNA is an acronym that stands for Deoxyribonucleic acid. It is found in the nucleus of a cell. It

is the genetic code for all living life forms.

How does forensic identification work?

Any type of organism can be identified by examination of DNA sequences unique to that

species. Identifying individuals within a species is less precise at this time, although when DNA

sequencing technologies progress farther, direct comparison of very large DNA segments, and

possibly even whole genomes, will become feasible and practical and will allow precise

individual identification. To identify individuals, forensic scientists scan 13 DNA regions that

vary from person to person and use the data to create a DNA profile of that individual

(sometimes called a DNA fingerprint). There is an extremely small chance that another person

has the same DNA profile for a particular set of regions.

Some Examples of DNA Uses for Forensic Identification

• Identify potential suspects whose DNA may match evidence left at crime scenes

• Exonerate persons wrongly accused of crimes

• Identify crime and catastrophe victims

• Establish paternity and other family relationships

• Identify endangered and protected species as an aid to wildlife officials (could be used for prosecuting poachers)

• Detect bacteria and other organisms that may pollute air, water, soil, and food

• Match organ donors with recipients in transplant programs

• Determine pedigree for seed or livestock breeds

• Authenticate consumables such as caviar and wine

Is DNA effective in identifying persons?

DNA identification can be quite effective if used intelligently. Portions of the DNA sequence

that vary the most among humans must be used; also, portions must be large enough to overcome

the fact that human mating is not absolutely random.

Consider the scenario of a crime scene investigation :

Assume that type O blood is found at the crime scene. Type O occurs in about 45% of...