In selective breeding, the organisms with the desired traits that are developed either naturally or mutagen induced are subjected to breeding to establish a pure breed with that genotype. It is the oldest form of genetic manipulation.
Cloning is a technology, through which “genetically identical copies,” can be produced either of the animals or humans by using embryo transfer.
By genetic engineering technology, a selected gene is modified and reinserted into an organism of the same species or a gene from an individual of one species is inserted into another species, now the resulting one is a “transgenic organism” in either of the cases.
Thus, the blanks can be filled with selective breeding; cloning; transgenic animals.