Cloning involves creating an organism with the same genetic material as the original organism. One way to clone an organism is by taking a somatic cell (any non-reproductive cell in the body) and transferring its nucleus to an egg cell that has had its nucleus removed. This new cell is then stimulated to develop into an embryo, which can be implanted in a surrogate mother to develop into a cloned organism.
It is not necessarily true that cloning is welcomed as an ethical and morally sound science, as there are many ethical and social concerns surrounding cloning, particularly in the context of cloning humans.
It is true that only one cell of the original organism is needed to initiate the cloning process, as this cell contains all the genetic information necessary to create a new organism.
The clone is similar to but not exactly like the original organism, as environmental factors can play a role in shaping an organism's development and behavior, in addition to genetic factors.
Finally, cloning does involve the asexual multiplication of the tissues of the original organism, as the new organism is essentially a genetic copy of the original organism.