PCR is used in:

Ans: d (All the above) Ref: Vasudevan, 4th ed, p. 443; 5th ed, p. 458Clinical applications of PCR-->> Diagnosis of bacterial and viral diaseases, medico-legal cases, diagnosis of genetic diseases, cancer detection, paleontological studies.Polymorphic markers and linkage analysis:* A pre requisite for successful linkage analysis is the availability of a large number of highly polymorphic markers dispersed through out the genome.* Polymorphism is a clinically harmless DNA variation that does not affect the phenotype. Mutation is a potentially harmful genomic variation.* There are highly repitative sequences in DNA usually found in non-coding spacer DNA.Major types of markers are:RFLP - Restriction fragment length polymorphism tire polymorphisms in which, presence or absence of mutations at restriction site produces fragment of varying length that can be visualized on southern blot.VNTR - Variable number of tandem repeats or mini satellite* Repeated units ranges from 20 - 70 bp.* The repeat is Hanked on both side by a restriction site and variation in the number of repeats produces restriction fragments of varying size.STRP - Short tandem repeat polymorphism or micro satellite repeats.* They are amplified through PCR.* Variation in the number of repeats produces PCR products of varying size - visualised on agarose gel.Single nucleotide polymorphism - These are single base polymorphisms that can be assayed by DNA sequencing or through DNA chips.VNTR: Mini satellite - 20 - 70 bpSTRP: Micro satellite - 2-6 bpSingle nucleotide polymorphism - single bp