Why is PCR performed on panda DNA from the faeces?

• A. To amplify RNA
• B. To increase amount of DNA
• C. To sequence genome
• D. To remove bacteria DNA

Answer: (B)

PCR's main idea is to produce large amounts of a specific DNA sequence from a tiny starting sample. In panda faeces, panda DNA is present only in trace amounts and is mixed with lots of other DNA from bacteria and the environment. By using primers that match panda sequences, PCR copies those target regions over many cycles, giving you millions of copies of panda DNA to work with. This makes downstream analysis, like sequencing or genotyping, possible even from a heterogeneous and small sample. The other options don’t fit: amplifying RNA would require a reverse-transcription step, PCR isn't used to sequence an entire genome in one go, and it doesn't remove bacterial DNA—it amplifies the chosen DNA region, allowing panda DNA to be studied when present.