Tissue culture is a high-tech version of the same process. Individuals cells of a plant can be grown aseptically in culture medium. Initially the cells form an undifferentiated cluster of cells, called a callus. These clumps can be divided up transferring them to other cultures producing literally thousands of genetically identical cell masses from an original cell. DNA carrying genes of interest can be inserted into the plant cells and new plants grown.
Plants have sex, too.
Iinvolves the production of haploid gametes followed by fertilization to produce a zygote which in turn develops into an adult that produces more gametes. There are many modifications of this basic process. In other words, they alternate between a diploid and haploid phase in the life cycle. The diploid phase is termed the sporophyte phase and the haploid phase is the gametophyte phase. The flower is the key feature of angiosperms.