Restriction Enzymes in Eukaryotic Cells — NEET Biology

Correct answer: B — S1 → S2 → S3 → S4 → S5 → S6

The core concept is the sequential steps involved in recombinant DNA technology. According to NCERT, the processes involved are "isolation of DNA, fragmentation of DNA by restriction endonucleases, isolation of a desired DNA fragment, ligation of the DNA fragment into a vector, transferring the recombinant DNA into the host, culturing the host cells in a medium at large scale and extraction of the desired product." Let's arrange the given statements based on this sequence: 1. **S1: Isolation of the genetic material (DNA).** (First step) 2. **S2: Cutting of DNA at specific locations using restriction endonucleases.** (After isolation, DNA is fragmented). 3. **S3: Separation and isolation of the desired DNA fragment.** (After cutting, the desired fragment is separated, typically by gel electrophoresis). 4. **S4: Ligation of the DNA fragment into a suitable vector.** (The desired fragment is joined with a vector using DNA ligase). 5. **S5: Insertion of the recombinant DNA into a competent host cell.** (The recombinant DNA is then introduced into a host). 6. **S6: Culturing the host cells in a medium at large scale.** (Transformed host cells are multiplied for desired product). Thus, the correct sequence is S1 → S2 → S3 → S4 → S5 → S6. The final answer is B because it represents the correct sequential order of the steps.