2. extract the DNA

DNA is contained in the nucleus of a cell. Chemicals are added to open the cell and extract the DNA to isolate it. 

3. copy the DNA
DNA is copied using a polymerase chain reaction to obtain enough DNA to create the profile. The DNA from between 11-13 loci is copied. It is very unlikely for two individuals to have the same number of repeats at each of these loci. 

4. determine the size of STRs

genetic analyzers determine the size of the STR at the genetic locus. The analyzer separates the copied DNA by gel electrophoresis and can detect the fluorescent dye on each STR. This equipment is also used for DNA sequencing. 

 
5. check for a match 

Hutzel, Angie. “FAQ About Paternity Tests.” The Spruce, www.thespruce.com/about-paternity-tests-1270746.

“Paternity Test.” Merriam-Webster, Merriam-Webster, www.merriam-webster.com/dictionary/paternity%20test.

Walpole, Brenda, Ashby Merson-Davies, and Leighton Dann. Biology for the IB 

Diploma. 2nd ed. United Kingdom: Cambridge UP, 2014. Print.

2.Gel electrophoresis is used to separate macro-molecules like DNA, RNA and proteins. DNA fragments are separated according to their size. Proteins can be separated according to their size and their charge different proteins have different charges.

3. (STR) analysis is one of the most useful methods in molecular biology which is used to compare specific loci on DNA from two or more samples meaning cops can use this. STRs with higher power of discrimination are chosen for human identification in forensic cases on a regular basis. It is used to identify victim, perpetrator, missing persons, and others.

4 

- Sense of identity, a child knowing to whom they are biologically linked
- Health history, hereditary factors influence preventative health measures
- Financial support, many households require two incomes to keep up with the cost of living
- Benefits, health insurance, social security and veteran benefits benefit biological children
- Government Aid, Paternity allows parents to seek government assistance if they qualify.

Paternal profiling is a test of DNA traits to determine whether a man is the biological father of a child. 

2. Outline what gel electrophoresis does. (2)

Gel electrophoresis is used to separate fragments of DNA based on size and the electric charge that they carry. Gel electrophoresis identifies natural variations in the DNA of any individual.

 3. Comment on tandem repeats. Are short tandem Repeats a viable forensic tool? (3)

Tandem repeats is a technique that is used for DNA profiling using polymorphisms. STRs are regions of non-coding DNA that have repeating patterns of the same nucleotide sequence and are used as a way of producing a DNA profile. The pattern of repeats are able to identify an individual to a high degree of accuracy so they are a very viable forensic tool.

4. Explain the importance of testing for paternity. (3)

Testing for paternity is important so that a child can know who their father is in order to improve family relationships and dynamics, establish custody or child support, for social benefits including social security and inheritance, to have an accurate family medical history, and for legal purposes.