This powerpoint explains about the process of cloning,its merits and demerits.

1. PREPARED BY
PRADHEES.C
B.Tech.,Biotechnology

2.  Cloning is an experimental technique
wherein, a group of genetically identical
organisms are produced.
 Cloning of various animals has become
possible due to knowledge gained in the field
of developmental biology and developmental
genetics.
 It helped a lot, to understand the genetic
control over differentiation of cells and the
development of multicellular organisms.

3.  Differentiation is an important term while
considering cloning.
 In the development of multicellular animals,
the zygote represents the progenitor cell of
the future embryo. Multitudes of cells arise
from mitotic divisions of the fertilized egg
cell.
 These cells later become distinct cell types
differing in form and function. This process is
called differentiation.

5.  Sperm cells(haploid-n) from male fertilize
with the ovum(haploid-n) of female.
 It results in the formation of diploid(2n)
zygote.
 The diploid zygote will be converted into an
embryo.

6.  Dr. Ian Wilmut has produced a cloned sheep
called Dolly by nuclear transplantation method.
 To produce cloned sheep he took the udder cell
which is a somatic cell with diploid number of
chromosomes.
 An egg cell was also removed from a donor
sheep.
 The egg cell cannot grow into a new sheep on its
own because it only has half a set of
chromosomes(n).
 The body cell cannot grow into a new sheep on
its own because it is not a reproductive cell. So
udder cell nucleus(2n) was removed.

7.  Similarly the egg cell nucleus (n) was also
removed.
 The nucleus of the somatic cell (Udder) was
injected into the enucleated egg.
 The egg after nuclear transplantation comes to
possess full set of chromosomes viz. the 2n
diploid.
 The egg was then transplanted back into the
uterus of the sheep from which it was removed.
 The egg also can be transplanted to a new
surrogate mother for development.
 The egg cell grew and developed into a sheep
(Dolly).
 This cloned sheep is genetically identical to the
donor sheep which donated the diploid nucleus
of its somatic cell and not the sheep which
donated the egg cell.

9.  Cloning will help to maintain biodiversity.
 It can bring back even the animals which have
become extinct recently and safe guard all
endangered species facing extinction .
 Though human cloning has its own ethical
problems, the principle could be used to grow
new organs from the cloned stem cells.
 Such organ culture may solve transplantation
problems, such as tissue incompatibility, tissue
rejection, harmful immune reactions etc.
 Many human lives could be saved through
cloning.

10.  When organisms are created by cloning from
somatic cells of the adult, the longevity of the
new born, disease tolerance capacity are some
criteria to be considered.
 Cloned animals have also developed diseases like
arthritis. Cloned animals may have health
problems. They may die at a much earlier
 age than the rest of the species.
 So cloned animals from somatic cells of adult,
may have short life span.
 cloning human may lead to the production of
wrong persons.