Question

1. Briefly describe the technique of DNA profiling. What are the practical applications of this technique?

2. What characteristics do karyotypes display?

Answer 1

DNA profiling is the process of identifying specific patterns of DNA sequences in individuals for distinguishing between them.

This is mostly used for forensics and paternity analysis. It is also used for genetic disease identification, chromoaomal anomaly identification, plant parentage identification, food contamination, endangered species identification, and DNA contamination from different sources.

It involves following steps

1 sample collection

2. dna isolation

3. Restriction digestion (by frequent or rare cutter)

4. Gel electrophoresis (separation of digested products)

5. Transfer to nylon or nitrocellulose membrane (southern blotting)

6. Probing by short tandem repeats probe. Short tandem repeats are the repeat sequence present at the telomere of human chromosome and the number of repetitive unit will be different in different individual and give specific pattern for each individual.

7. Autoradiography. Where we can see the DNA profile of individuals.

Karyotypes characteristics

Karyotype will represent the number of chromosome, the size of it and its structure. For example normal human Karyotype will represent 22 pair autosomal chromosome, with x and y sex chromosome for male and xx chromosome in female. If individual have some defects then matching pair of autosomes could be missing, some broken or damge part will be present or loss of chromosome can be find out.