Recombinant DNA and Genetic Engineering

All three statements are correct. Recombinant DNA technology enables gene transfer across species boundaries: (1) genes can be transferred between different plant species (e.g., crop improvement), (2) genes from animals can be inserted into plants (though less common, it is theoretically and practically possible), and (3) genes from microorganisms to higher organisms is a well-established practice (e.g., Bt toxin from Bacillus thuringiensis into crops). The power of genetic engineering lies precisely in its ability to transcend biological boundaries. > Remember: Recombinant DNA = no species barriers; transfers work across kingdoms (plants, animals, microbes). Answer: d.