History Of Cloning

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be used for cloning. Others confirm their results.

1993- Embryologists at George Washington University cloned human embryos: they took
cell groups from 17 human embryos (defective ones that an infertility clinic was going to
discard), all two to eight cells in size. They teased apart cells , grew each one in a lab dish
and a few got to 32 cells- a size when they can be planted into a surrogate mother,
although they weren't.

1994- Neal First cloned calves that have grown to 120 cells.

1996- Ian Wilmut repeated First's experiment with sheep but put embryo cells into a
resting state before transferring their nuclei to sheep eggs. The eggs developed into
normal embryos then into lambs.

1997- Ian Wilmut and his colleague Keith Campbell clone an adult sheep.
Different Methods: Of Cloning
The most famous sheep in history, Dolly, was cloned by using the method of Nuclear
transfer. Previously the only cloning was either done on plants or frogs or mice. In this
section the different processes will be described.

PLANT CLONING
Gardeners have been cloning plants for centuries and plants have been doing it for longer.
Here are three different types of cloning out of many. One type of plant cloning naturally
occurs when a plant grows a runner. The runner grows horizontally across the ground
forming a carbon copy of that same plant at the end. Eventually the runner dies and the
daughter plant is separated from the mother plant. Another is when you cut a branch or
leaf off of a plant and plant it. It will grow another identical plant. That method is called a
cutting. A stolon is where a weak branch of a plant falls over and the tip touches the
ground. The tip swells and roots are formed so that growth in the plant can continue.

ANIMAL CLONING
Lower forms of animals clone themselves quite often like amoeba's and paramecium which
use binary fission to split themselves in half and create a new but identical anima...