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Cloning
Clones are groups of genetically identical organisms
from one single parent cell
• Occur naturally in plants and animals
• Can be engineered through genetic
manipulation
Naturally Occurring Clones
Identical Twins (or Monozygotic
Twins): Same exact genetic
information
Plant cuttings: Stem cells throughout the plant
can differentiate into roots stems or leaves
creating a new genetically identical plant from
the parent plant
Asexual Reproduction:
Creates genetically identical
organisms. Ex: Binary fission
in bacteria
Cloning Animal Embryos
Embryos can naturally split
forming identical twins or they
can be artificially split.
• If an embryo is artificially
split, it must be done early
while the cells are
pluripotent and have not
differentiated.
• This method creates a
limited number of clones
– As the embryo develops it
differentiates and the cells
can no longer be used
Cloning From Adult Animals
Adult cells have already differentiated. But each cell still contains all
of the genetic info of the whole organism.
• The nucleus of a differentiated adult cell can be transferred to the
nucleus of an egg cell to create a clone of the adult.
1. The egg cell’s nucleus
must be removed
2. The nucleus from any cell
of the adult to be cloned is
removed and inserted into
the egg cell
3. The egg cell is placed into
a surrogate mother to
develop
4. The mother gives birth to
a genetically identical
organism of the adult that
was cloned
Plant Cuttings
• Plant stem cuttings are clones of
the adult plant
– Roots will form from the cut
through meristem cells found in
the nodes of plants – these
function like stem cells, able to
differentiate into different types
of tissues
• Meristem cells can also be coaxed
into forming by applying a rooting
hormone: auxin.
Brainstorm
What factor could you investigate that might
affect the rate of root growth in a plant cutting?