Restriction enzymes have been used to cut a required gene from donor DNA and to open a plasmid. A scientist prepares two cell-free mixtures.
| Mixture | Complementary sticky ends able to pair | DNA ligase added |
|---|---|---|
| R | yes | no |
| S | no | yes |
Which conclusion about the changes needed to form recombinant plasmids is supported by the information in the table?
Add a restriction enzyme to R; use DNA ligase to make complementary sticky ends in S.
Cut the gene and plasmid with the same restriction enzyme in R; add DNA ligase to S.
Add DNA ligase to R; cut the gene and plasmid with the same restriction enzyme in S.
Use DNA ligase to cut the DNA in R; add a restriction enzyme to seal the DNA in S.
100 exam-style questions on Edexcel GCSE Biology 4.3 Selective breeding and genetic modification, covering 4.3.1 Selective breeding and its impact, 4.3.2 Tissue culture, 4.3.3 Genetic engineering overview, 4.3.4 Main stages of genetic engineering, 4.3.5 Advantages and disadvantages of GM organisms, 4.3.6 Agricultural solutions for a growing population, and 4.3.7 Evaluating genetic engineering and breeding. Each one has a worked solution and a mark scheme showing where the marks go.