When an organism reproduces asexually, its offspring will be its clone. That is because the offspring only receives its DNA from a single parent.
An example of a naturally occurring clone is when a hydra forms a bud. This bud can break off and live independently of its parent. However, it is genetically identical to the parent and therefore a clone. Sponges can also reproduce by budding. Anything that reproduces with a single parent produces identical offspring and thus, a clone. Another example of naturally producing a clone is starfish regeneration. If an arm is removed with a portion of the central disk, it will grow into a complete starfish and is a clone of the original starfish. Binary fission in bacteria and sporulation in molds are also natural ways in which clones are produced of a parent.
Through artificial methods, cloning is also possible. Dolly the sheep was the first successful clone of an adult mammal. This was accomplished in 1996. A donor cell was taken from an adult sheep's udder. This was a diploid cell with a complete genetic blueprint. Next, an egg cell was enucleated, which means its DNA was removed. Using electric shock, the two cells were fused. This cell began to undergo mitotic divisions. The embryo that formed was implanted in a surrogate mother's uterus where it developed into a cloned lamb. This clone was genetically identical to the sheep whose udder cell provided the DNA.