1. DNA Profiling
C_Daniel Yoon

2. What is DNA Profiling?
A technique used to identify individual by encrypting sets
of numbers that reflect a person’s DNA makeup. (Often
used in parental testing and criminal investigation)

3. Assessment Statement related to
DNA Profiling
4.4.3 State that gel electrophoresis of DNA is used in
DNA profiling.
4.4.4 Describe the application of DNA profiling to
determine paternity and also in forensic
investigations.
4.4.5 Analyse DNA profiles to draw conclusions about
paternity or forensic investigations.

4. How does gel electrophoresis
work?
Gel electrophoresis is used to separate DNA (or other
molecules) by their size and charge. The DNA fragments
move in an electric field. The negatively charged DNA all
moves towards the positive electrode. Small pieces move
farther than large pieces.

5. Procedure of DNA Profiling
1. DNA samples are taken and amplified with PCR
2. Restriction enzymes cut DNA into fragments at specific base sequences
in each sample
3. a fluorenscent marker blinds to a triplet in the DNA fragments, so that
results can be seen
4. Samples are added to a gel electrpphoresis chamber. Electric current is
passed through, pushing the fragments along
5. Heavier fragments stay closer to the origin and smaller fragments go
further
6. a banding pattern shows up for each DNA sample and can be compared

7. What is PCR (polymerase chain
reaction) used for?
-copy and amplify tiny quantities of DNA. Very useful if
you only have a small sample of DNA (like from a blood
sample from a patient or a crime scene) and you need lots
of DNA to do DNA profiling.

8. Which electrode (positive or
negative) will DNA travel towards
in gel electrophoresis? Why?
positive electrode; DNA is negatively charged (think of all
of those phosphate groups!). Note that if the electrodes are
not labelled in a gel

9. 4.4.5 Analyse DNA profiles to
draw conclusions about paternity
or forensic investigations.

10. From i-Biology

12. From Senior biology Book
Microsatellites(short tandem repeats): repeating
sequences(2-6 base pairs)
Because noncoding nucleotide sequences repeat
throughout the genome, the finding of repeating
sequences(DNA profiling) is possible.

13. 4.4.4 Describe the application of
DNA profiling to determine
paternity and also in forensic
investigations.
Organisms have short sequences of bases which are repeated many times.
These are called satellite DNA. These repeated sequences vary in length
from person to person. The DNA is copied using PCRand then cut up into
small fragments using restriction enzymes. Gel electrophoresis separates
fragmented pieces of DNA according to their size and charge. This gives a
pattern of bands on a gel which is unlikely to be the same for two
individuals. This is called DNA profiling. DNA profiling can be used to
determine paternity and also in forensic investigations to get evidence to
be used in a court case for example.

14. http://en.wikipedia.org/wiki/DNA_profiling
http://i-biology.net/ibdpbio/04-genetics-and-genetic-
engineering/genetic-engineering-and-biotechnology/
http://flashcarddb.com/cardset/14805-ib-4-4-genetic-
engineering-and-biotechnology-flashcards