Transcript clones - Noadswood Science

Cloning
L.O: To understand the process of
cloning
D. Crowley, 2007
Read the cloning article. Do you think it is pro
or anti?
What do these people have in common?
What do these people have in common?
What do these have in common?
Cloning
• What is a clone? Is it natural?
• Exact copies of organisms are called clones - they have
identical genetic information as the organism they were
cloned from
• Cloning is the production of genetically identical copies
• Clones frequently occur naturally, but they can also be
produced artificially
1. Cloning Plants
• Plants are easy to clone - gardeners often take cuttings to
grow new plants which are clones. They often use hormone
rooting powders to encourage them to grow.
• Cloning is an example of asexual
reproduction (where genetic
information comes from just one
parent).
2. Tissue Culture
e.g. plants and skin grafts
What is the advantage of this method?
And what is a disadvantage?
Plants Pros & Cons
• Cloning of plants is very important commercially - successful varieties of
plants can be produced on a large scale in a short space of time
• Can you think of any pros / cons of plant cloning?
Advantages of plant cloning
Disadvantages of plant cloning
Lots of new plants can be grown in
a short time period
All plants have the same genetic
information - all are vulnerable to
the same disease / pest
Conditions can be precisely
controlled
No new beneficial characteristics
will arise (as they do by chance
naturally)
All new plants get the
characteristics you want - e.g.
disease resistant
No variation causes the gene pool
(no. of genes in a population) to be
reduced
3. Embryo Transplant
This method allows you to produce more than 1 clone
from 1 embryo. You can even select the features
you want by choosing the sperm and egg initially.
1. Divide a fertilised embryo into several individual
cells.
2. Each cell grown into an identical embryo in the
lab.
3. The embryos are transferred to host mothers
which have been given hormones to get them
ready for pregnancy.
4. Identical cloned calves are born (not related to
the mothers).
4. Fusion Cell Cloning
E.g Dolly the sheep: -
http://learn.genetics.utah.ed
u/content/tech/cloning/click
andclone/
1.
An egg cell was removed from the ovary of an adult female sheep, and
the nucleus removed.
2.
The empty egg cell was fused with DNA extracted from an udder cell of a
donor sheep by electric shock.
3.
The fused cell now began to develop normally, using the donated DNA
4.
Before the dividing cells became specialised the embryo was implanted
into the uterus of a foster-mother sheep - the result was Dolly,
genetically identical to the donor sheep.
Animals Cloning Pros & Cons
• Animal cloning has potential uses in both farming and medicine (for
protein synthesis (manufacturing proteins), gene therapy (adding /
replacing specific genes to treat diseases) and organ donation (e.g.
kidneys from pigs which can be used in humans))
Advantages of animal cloning
Disadvantages of animal cloning
Allows you to check the embryo for
defects
No new beneficial characteristics
will arise (as they do by chance
naturally)
Allows you to choose the sex and
time of birth
All animals have the same genetic
information - all equally vulnerable
to the same disease or predator
Exact copies of the ‘best’ animal
can be made year after year
(selective breeding)
No variation causes the gene pool
(no. of genes in a population) to be
reduced
Could be used in saving
endangered species from extinction
Animal welfare concerns - cloned
animals tend to die young*
*Interestingly cells seem to ‘know’ their age - so a cloned animal, although just born,
on a cellular basis is as old as its donor parent!
Cloning Cauliflower
1. Using the sterile forceps pick up a piece of
cauliflower and put both into the bleach for 10
minutes
2. Using the forceps move the cauliflower to
solution 1 and leave for 1 minute
3. Repeat step 2 twice more into solution 2 and
3.
4. Quickly move the cauliflower to the growth
medium and cover it with the foil immediately
How could you clone a frog?
Select the best method from tissue culture,
embryo transplant or fusion cell (adult cell
cloning).
Describe a step by step
method using diagrams
and writing.