Question 21M.2.SL.TZ1.8a
| Date | May 2021 | Marks available | [Maximum mark: 4] | Reference code | 21M.2.SL.TZ1.8a |
| Level | SL | Paper | 2 | Time zone | TZ1 |
| Command term | Outline | Question number | a | Adapted from | N/A |
Outline the process of DNA profiling.
[4]
a. sample of DNA obtained from person/hair/blood/mouth/crime scene ✔
b. PCR used to amplify/make copies of DNA (in sample) ✔
c. using Taq DNA polymerase / using DNA polymerase from thermophilic bacteria ✔
d. tandem repeats amplified/used ✔
e. gel electrophoresis used to separate DNA (into bands) ✔
f. separation according to length of fragments/number of repeats
OR
fragments of same length/number of repeats travel same distance ✔
g. pattern of bands/numbers of repeats is the profile/is unique to the individual ✔
h. example of application/forensics/crime investigation/paternity ✔
Do not accept ‘determine ancestry’ for mph. Other genes/chromosomes are more often used for that.
Accept STR for (short) tandem repeat in mpd.
There were some good outlines of DNA profiling. Most knew at least one application of the process. There was some confusion between profiling and sequencing and the use of tandem repeats was often missed.
