In molecular and cell biology, the term “transfection” specifically refers to what process?

Introduction / Context:
Transfection is a core technique used to study gene function, produce recombinant proteins, and engineer cells. The term is often confused with transcription, translation, or transformation, so precise definition is important for students and practitioners.

Given Data / Assumptions:

• Focus is on eukaryotic cells (mammalian, insect, plant protoplasts).
• Foreign nucleic acids can be plasmid DNA, siRNA, mRNA, or CRISPR components.
• Delivery methods include chemical (lipids, calcium phosphate), physical (electroporation), or viral vectors (often termed transduction).

Concept / Approach:
Transfection means introducing exogenous nucleic acid into eukaryotic cells, either transiently (short-term expression) or stably (genomic integration or episomal maintenance). Do not confuse with transcription (RNA synthesis) or translation (protein synthesis), which are endogenous cellular processes.

Step-by-Step Solution:

Verification / Alternative check:
Laboratory manuals define transfection as nucleic acid introduction; “transduction” is specifically viral-mediated delivery, a subset often discussed separately.

Why Other Options Are Wrong:

• Transcription and translation are intracellular biosynthetic processes.
• Malignant transformation is a biological outcome, not a nucleic-acid delivery method.
• Cell fusion is a different technique (e.g., to make hybridomas).

Common Pitfalls:
Using “transformation” (bacterial uptake) interchangeably with “transfection” (eukaryotic); mixing up transduction terminology.

Final Answer:
Introduction of foreign nucleic acid (DNA/RNA) into a eukaryotic cell