Transcript Document

Unit Eight
Cloning
What is cloning?
• Cloning is the process of making a
genetically identical organism through
nonsexual means.
• In genetic engineering, cloning refers to
the copying of DNA molecules.
Cloning Milestones
• 1938 Cloning is envisioned. Hans Spemann proposed
•
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what he called a "fantastical experiment." He suggested
taking the nucleus from a cell of a late-stage embryo
and transplanting it into an egg. In other words, cloning.
1952 First cloning experiment with frogs. Robert
Briggs and T. J. King used a pipette to suck the nucleus
from the cell of an advanced frog embryo and added it
to a frog egg. It did not develop.
1984 First embryo cloning with sheep is reported.
Steen Willadsen reported that he cloned a live lamb from
immature sheep embryo cells. Others later replicate his
experiment using a variety of animals, including cattle,
pigs, goats, rabbits and rhesus monkeys.
• 1994 First cloning of
more advanced
embryo cells. Neal
First cloned calves
from embryos that
have grown to at
least 120 cells.
• 1996 Dr. Ian Wilmut
and his team clone
the world's the first
sheep from adult cells.
The lamb born in July
1996 is named Dolly.
• 1997 A team led by
Drs. Ian Wilmut and
Keith Campbell (U.K.)
create the first sheep
with a human gene in
every cell of its body.
The genetically
engineered lamb is
named Polly.
• 2000 Japanese scientists clone a baby bull from a
bull that was a clone itself, the first re-cloning case
involving a large mammal.
• 2002 A team of scientists at Texas A&M University
produces the first cloned pet, a calico kitten called
“CC” (for Copy Cat). The work was funded by
Arizona millionaire John Sperling, whose company,
Genetic Savings and Clone, hopes to clone pets for
profit.
China’s Breakthroughs in Cloning
• 1999 Chinese scientists have produced an
•
embryo of a giant panda through cloning
technology, a breakthrough that could save the
endangered animal. scientists from the Chinese
Academy of Sciences had introduced cells of a
dead female panda into the egg cells of a
Japanese white rabbit and the embryo was
nurtured successfully.
2003 Chinese scientists have produced human
embryonic stem cells by mixing human skin with
rabbit eggs. This experiment would represent
the first time human embryonic stem cells had
been generated via cloning.
Human cloning
• Human cloning is a very controversial
issue and there are many advantages
and disadvantages.
Major Advantages of human
Cloning
• One advantage would be
the issue of talents and
that some of them seem to
be influenced genetically,
such as musical ability.
Cloning using the DNA
from an adult who is
musically talented could
result in a cloned child
growing up to be equally
talented. (continued)
• In the case where a husband is sterile and can
not produce a child sexually he could contribute
a cell from his body and through this type of
cloning the wife and husband could both
contribute to a cloned child, where the wife
would provide the so called factory for raising
the baby while the husband would provide the
genetic information. This could be a viable
option instead of using sperm from another man.
A similar situation might be if two women would
like to have a child together. They could use this
cloning technique instead of going the way of
artificial insemination.
Major Disadvantages of Human
Cloning
• there is a high chance that the clone will not be
•
normal. It may have some disorder; either
starting at birth or the clone may get a disorder
or disease related to the cloning process later in
life.
There is also the issue of the cells aging. Cells
are believed to have a set life span and that
using an aged cell of say an adult human would
result in the cloned child starting off with cells
already aged thus having an effect on that
child’s life span.
• Another problem is that
•
after the technique of
using a female egg and a
female cell to make a
clone there would really
be no genetic need for
men.
Another issue is diversity;
if cloning is done large
scale genetic diversity
could be depleted.
Diversity is really what
the human race is all
about, so this could be a
disaster.
• A huge case against human cloning is the
•
emotional effects on the clone, for example a
cloned child would in effect be a twin of one of
his parents which could lead to serious
emotional difficulties.
There is also the religious side of things. For
example, whether or not removing the nucleus
is murder or whether or not the cloned human
would have a soul. Some religious people
believe that the soul enters the body when a
sperm fertilizes an egg, but since sperm is not
used during the reproductive cloning process
there may not be a soul present, which gets
into some pretty deep controversy.
Text A
A Clone Is Born
Text Organization
• Part One
(Paras 1-2)
Dolly the sheep, a
clone, was born.
• Part Two
(Paras 3-6)
Dolly’s birth has
made cloning a
reality and human
cloning a possibility.
• Part Three
(Paras 7-11)
People have to face the ethical problems
of human cloning.
This part can be further divided into…
Section One (Paras 7-9): Human cloning
has given rise to the question of what
implications the technology may have for
mankind.
Section Two (Paras 10-11): The making of
the atomic bomb had a tremendous
impact on scientists.
• Part Four
(Paras 12-16)
Cloning technology could benefit people in
more than one way.
Cultural Notes
• Narcissus
• Prometheus
• Oppenheimer, (Julius)
Robert
• Hiroshima
• Nagasaki
Language Points
• give birth to: produce young; bring about
The cat gave birth to five kittens.
This issue gave birth to a dispute.
• for all the world like sth. / sb. /as if:
very much or exactly like someone or something
or as if…
She carried on with her work for all the
world as if nothing had happened.
• fuse: join sth. or become joined by means of
heat
In her richest work she fuses comedy and
tragedy.
• residence: process of residing; place in which
one lives
Residence among the poor is suggested as a
way of understanding their problems.
Downing Street is the British Prime Minister’s
official residence.
• identical (to / with): exactly alike; the same
On Monday, the pupils wear identical school
uniforms.
cp. identify & indentity
identify (with): consider as identical or united
We shouldn’t identify happiness with wealth.
identity: the set of behavioral or personal
characteristics
This check will be cashed on proof of identity.
• in principle: as far as basic principles are
concerned; in general but not in detail
Though there is no reason in principle why
women cannot be top leaders, they work in
reality under men more often than not.
They have agreed to the proposal in principle
but we still have to negotiate the terms.
• offensive: upsetting or annoying; disgusting or
repulsive
Why did he make such offensive remarks at
the meeting?
An offensive smell greeted my nose when I
opened the door.
cp. offend: cause displeasure; violate a rule or
law
Some music offends, rather than pleases, the
ear.
• compromise: n. giving up of certain demands
by each side in a dispute, so that an agreement
may be reached which satisfied both; v. settle a
dispute by making compromise (on / over)
The NATO countries have finally reached a
compromise over whether the US-led
multinational troops are justified in launching
attacks against Iraq.
I want to go Greece, and my wife wants to
go to Spain, so we compromise on Italy.
• let loose: release
When we escape, shall we let loose other
prisoners?
Just close your eyes and let loose your
imagination.
• deadly: causing or likely to cause death
deadly weapons
cp. deathly: like or suggesting death
The whole village was shrouded in deathly
silence.
• lash out at: make a sudden violent attack on with
blows or words
He lashed out at the ruling party’s foreign policies.
• start out: intend when starting; begin (a journey)
They started out to want a house, but eventually
bought a flat.
With the help of the Spanish king, he started out his
journey across the Atlantic Ocean.