Science and Technology · Biotechnology

In the context of assisted reproductive technologies, consider the following techniques: I. Transfer of nuclear genetic material from a fertilised egg into an enucleated donor egg. II. Replacement of defective mitochondrial DNA through spindle-based nuclear transfer. III. Exchange of cytoplasmic contents between donor and recipient oocytes without nuclear transfer. How many of the above techniques are associated with the concept popularly referred to as 'three-parent babies'?