. Name two feature of PCR that make this technology useful in molecular diagnostics and forensics [2]2. a) What are STRs and what makes them useful in forensic science?b) What is the major difference between RFLPs and STR analysis?3. In microarray technology:a) What must the mRNA be converted to before it may be bound by specific nucleotide probes and howis this done?b) How would you control the stringency of hybridization?c) Name two limitation of this technology4. In qPCR, what is the Ct value used to quantify gene expression?[3][1][2][2][2][2]

PCR (Polymerase Chain Reaction) is a useful technology in molecular diagnostics and forensics due to two main features: a) Amplification: PCR can amplify a small amount of DNA, making it possible to analyze even trace amounts of genetic material. This is particularly useful in forensics where only a small sample may be available. b) Specificity: PCR is highly specific. It can target a specific sequence within a complex DNA sample. This allows for the identification of specific organisms or individuals, which is crucial in both diagnostics and forensics.

a) STRs (Short Tandem Repeats) are sequences of DNA that repeat a certain number of times in a row. They are useful in forensic science because the number of repeats varies greatly among individuals, making them a good tool for identifying individuals. b) The major difference between RFLPs (Restriction Fragment Length Polymorphisms) and STR analysis is that RFLPs look at the length of DNA fragments cut by specific enzymes, while STR analysis looks at the number of repeats in specific DNA sequences.

In microarray technology: a) The mRNA must be converted to cDNA (complementary DNA) before it can be bound by specific nucleotide probes. This is done using the enzyme reverse transcriptase. b) The stringency of hybridization can be controlled by adjusting the temperature and salt concentration during the hybridization process. c) Two limitations of this technology are: it requires a large amount of sample and it can only detect known sequences.

In qPCR (quantitative PCR), the Ct value (Cycle threshold) is used to quantify gene expression. The Ct value is the number of cycles needed for the fluorescence of a PCR product to exceed a certain threshold. It is inversely proportional to the amount of target nucleic acid in the sample, meaning a lower Ct value indicates a higher amount of target nucleic acid.