Question

Transgenic plants are the ones
A. Produced after protoplast fusion in an artificial medium.
B. Grown in an artificial medium after hybridization in the field
C. Produced by the somatic embryo in an artificial medium
D. Generated by introducing foreign DNA into a cell and regenerating a plant from that cell.

Answer 1

With the help of recombinant DNA technology, we can alter the genetic makeup of plants and produce new plants with certain qualities. These are called transgenic plants.

Complete answer: Organisms whose genes are altered by adding fragments of DNA with the desired genes or deleting harmful genes from them are called genetically modified organisms. It is done with the help of recombinant DNA technology. Transgenic plants are examples of genetically modified plants. Genes with desired characters are introduced into the plants with the help of vectors that act as vehicles for carrying the DNA. We have developed many pest resistant, disease resistant, high yielding plants by this process. Bt plants are examples of transgenic plants. Genes from bacteria called Bacillus thuringiensis is introduced to the plant DNA that gives the plants resistance from the attack of insects. Bt-cotton, Bt-brinjal, etc are examples. With the help of modern technologies, scientists have developed methods to isolate protoplasts of the plants by digesting their cell walls with the help of lytic enzymes. Isolated protoplasts from two plants having desired characters are fused together and grown in an artificial medium. This method of production of plants by fusing protoplasts from two plants is called somatic hybridization.
Hence, the correct option is D.

Note: We use several vectors for the transfer of DNA. Bacteriophages are viruses that infect bacteria. These are used to carry DNA to the bacterial cell. Plasmid DNA of bacteria is also used as a cloning vector for this purpose.