Applications of PCR: In modern biosciences, PCR is commonly used for which of the following purposes?

Introduction / Context:
PCR is a versatile platform technology. By rapidly producing large amounts of a specific DNA segment, it underpins numerous workflows in research, medicine, and law enforcement.

Given Data / Assumptions:

• PCR yields abundant target DNA suitable for downstream processes.
• Sequencing typically requires amplified templates or library preparation from PCR products.
• Diagnostics and forensics rely on sensitivity and specificity of PCR amplification.

Concept / Approach:
In cloning, PCR-amplified inserts are ligated or assembled into vectors. In sequencing, PCR enriches target regions or constructs libraries. In diagnostics, pathogen or mutation-specific primers detect disease; in forensics, short tandem repeats are amplified for human identification.

Step-by-Step Solution:
Relate PCR output (many copies of a target) to cloning workflows.Recognize PCR’s role in Sanger and next-generation sequencing preparations.Identify medical and forensic use cases (pathogen detection, STR profiling).Conclude that all listed uses are valid.

Verification / Alternative check:
Standard protocols across molecular biology labs incorporate PCR steps for each listed application, confirming the breadth of use.

Why Other Options Are Wrong:

• Any single option alone is incomplete; PCR is used in all these areas.

Common Pitfalls:
Ignoring contamination control; carryover can cause false positives—use controls and physical separation of pre- and post-PCR areas.

Final Answer:
all of the above