GENETICS - Bioenviroclasswiki


14 déc. 2012 (il y a 9 années et 1 mois)

478 vue(s)

Things to Do

As you enter the class collect one laptop,
make sure you write your name and also the
number of the laptop in the book.

Complete your warm
up Quiz and get ready
for the class.

There is a big difference between

cloning and



cloning involves creating an embryo and then
actually implanting it into a uterus. It is highly unlikely this
could work for humans, and for ethical and scientific
reasons, all but a handful of radical scientists are strongly
opposed to attempting it.

cloning creates an
embryo but never implants this in a uterus as it intends to
only create patient specific stem cells, not a person.

Many countries and some US states already have legislation
that permits

cloning while continuing to

cloning. The vast majority of scientists
support the prohibitions against reproductive cloning.



“Big Question”

have the technology to change the
biology and chemistry of living organisms but
should they?

Share your thoughts with your partner and list
down what you both think. We can then share
it with the class.

Time 2 minutes.

up Video

Be prepared
to answer

“Cloning could be considered one of the greatest
discoveries of all time!” after watching the video, what are
your thoughts on cloning? Can it be beneficial to society?

I expect each one of you to give what you feel about cloning
after watching the video and whether it will be beneficial to

Enduring Understanding

We have the technology to manipulate DNA:


Designer Babies

Some families have difficulties in conceiving
that can be overcome


Learning Activities

up quiz( On the Previous day Lesson)

Quiz time

Online quiz on animation

Case Study

analysis with a partner

Venn diagram

Determine the similarities and
differences between reproductive and therapeutic

Venn Diagram

Pros and cons of cloning

Project presentation on

Just Because We Can, Does it Mean We Should?

Choose any one of the topics given and present your
findings before the class.


Be an active participant, in fact I would like to
learn from you today.

I would like you to watch all animations/video
very carefully and be prepared to answer at the
end of the animation. Be alert as the animations
don’t have music but it is followed by questions.

You will be given a case study on cloning, an
article on cloning, article on ethics and Human
Guess what?

You can have a laptop for use today to clone.

How is Cloning Done?

In nature, twins occur just after fertilization of an egg cell by a sperm cell. In
rare cases, when the resulting fertilized egg, called a zygote, tries to divide
into a two
celled embryo, the two cells separate. Each cell continues dividing
on its own, ultimately developing into a separate individual within the
mother. Since the two cells came from the same zygote, the resulting
individuals are genetically identical.

Artificial embryo twinning uses the same approach, but it occurs in a Petri
dish instead of in the mother's body. This is accomplished by manually
separating a very early embryo into individual cells, and then allowing each
cell to divide and develop on its own. The resulting embryos are placed into
a surrogate mother, where they are carried to term and delivered. Again,
since all the embryos came from the same zygote, they are genetically

Somatic Cell Nuclear Transfer

This was the method used to create Dolly the Sheep.

To make Dolly, researchers isolated a
somatic cell

from an
adult female sheep. Next, they


from that cell to an egg cell from which the nucleus had
been removed. After a couple of chemical tweaks, the egg
cell, with its new nucleus, was behaving just like a freshly
fertilized zygote. It developed into an embryo, which was
implanted into a surrogate mother and carried to term.

The lamb, Dolly, was an exact genetic replica of the adult
female sheep that donated the somatic cell nucleus to the
egg. She was the first
ever mammal to be cloned from an
adult somatic cell.

Video on cloning Dolly the sheep

Biology: Nuclear Transfer

Before you actually see an animation on SCNT I would like you to see a
very short video on Nuclear Transfer and the sterile technique involved.

Cloning 101 You Tube

Dolly the Sheep Animation

Video on dolly the Sheep, one you need to watch later at home

How does SCNT differ from the natural way of
making an embryo?

Natural Reproduction and Somatic cell
Nuclear Transfer ( this link is good for review)

You can write an answer to this question in
your note book.

Do you want to Clone a mouse and
have fun?


Now that you know the steps involved in
SCNT, you can have fun in cloning this mouse
by making use of the above link and it is a
good review as well.



Now that you have a fair understanding of
cloning be ready to take up a quiz.

It is based on just the concept of cloning.

IS It Cloning or not?

Test your cloning savvy with this interactive quiz.

Play Cloning

I would like each one of you to answer this questions.
Those who know the answer Don’t have to get super
excited. As usual I will call out the name of the person.
Everyone will get a chance to play this game.

Have Fun.

Cloning using undifferentiated cells

Therapeutic cloning

Making copies of cells is known as therapeutic cloning
and its aim is to develop cells which have not yet gone
through the process of differentiation.

Since the first technique in this are involved using
embryos, the cells are referred to as embryonic stem
cells. Human embryos are produced and allowed to
grow for a few days into a small ball of cells. These cells
are not yet specialized and when SCNT is used, the cells
can grow into any of a large number of different
specialized tissues.

Other sources of stem cells are cells from the umbilical
cord or cells from aborted fetuses

Therapeutic Cloning

Aims at cell therapy where diseased cells are
replaced with healthy ones.

Cell therapy is used for people suffering from
Parkinson’s disease, patient suffering from spinal
cord injury.

Bone marrow transplants for patients with
leukemia, new skin cells for burn victims and to
grow new corneas for some forms of visual
impairments are examples of therapeutic cloning

4.4.13 Discuss the ethical issues of therapeutic
cloning in humans

Arguments in favor of cloning focus on:

The ability to cure serious diseases
with cell
therapy: currently leukemia and in the future
possibly cancer and diabetes.

Growing skin to repair a serious burn

growing new heart muscle to repair an ailing

Growing new kidney tissue to rebuild a failing

4.4.13 Discuss the ethical issues of therapeutic
cloning in humans

Arguments in favor of cloning focus on:

The ability to cure serious diseases
with cell
therapy: currently leukemia and in the future
possibly cancer and diabetes.

Growing skin to repair a serious burn

heart muscle to repair an ailing heart

Growing new kidney tissue to rebuild a failing

Is it ethically acceptable to generate a new
human embryo for the sole purpose of medical

Some of the concerns raised about therapeutic
cloning relate to:

Fears of it leading to reproductive cloning

Use of embryonic stem cells involves the creation
and destruction of human embryos (although it is
possible to use embryos left over from IVF
treatment which would be destroyed otherwise

Embryonic stem cells are capable of many
divisions and may turn into tumors.

Case study

Cloning Case Study

Therapeutic cloning cures Parkinson's mice


I would like you to read the case study and also the
articles given to you and give your opinion when

Silent reading time

3 minutes/4 minutes

Venn Diagram


Links that can help you

Draw Venn diagram to determine similarities
and differences between reproductive and
therapeutic cloning.

Draw Venn Diagram to illustrate pros and cons
of cloning


Cloning for medical purposes

Cloning stem cells for research

" for drug production

Reviving Endangered or Extinct Species

Could we really clone dinosaurs?

What would you need to do this?

Do you think a closely related species which
can serve as a surrogate mother is available?

Do you think DNA of the dinosaur can remain
undamaged for such a long time?

"Can we really clone endangered or
extinct animals?"

Can we really clone endangered or extinct

To date, the most successful attempt
to do so was the cloning of a gaur, a

animal from southeast
Asia. Scientists used a cow to bring
the cloned baby gaur, named Noah,
to term. Two days after birth,
however, Noah died from a common
bacterial infection

More interesting news on Cloning

Is Cloning Endangered Species the solution to

Other endangered species that may be cloned
include the African bongo antelope, the
Sumatran tiger, the cheetah and the giant panda.

Cloning extinct animals such as the wooly
mammoth or Tasmanian tiger is much more
due to the lack of properly conserved

Efforts are underway to clone the very recently

mountain goat, formerly of
. However, if this effort succeeds it will only
produce female clones. Scientists speculate they
may be able to remove one X chromosome and
add a Y chromosome from a related goat species
to make a male.

Cloning Humans?

To clone or not to clone: that is the question. The
prospect of cloning humans is highly controversial and
raises a number of ethical, legal and social challenges
that need to be considered.
Why would anyone want
to clone humans? Some reasons include:

To help infertile couples have children

To replace a deceased child

From a technical standpoint, before humans are
cloned, we need to have a good idea of the risks
involved. How sure can we be that a cloned baby will
be healthy? What might go wrong?

When will stem cell research lead to new disease cures?

Limited stem cell
based therapies are already
in widespread clinical use, in the form of bone
marrow and cord blood transplants. These
procedures, which save many lives every year,
demonstrate the validity of stem cell
transplantation as a therapeutic concept.
Similar successes should be possible with
unlimited stem cells for many other diseases,
but it is impossible to predict how soon this
will happen.

Human Cloning?

Preliminary experiments have shown that it may
be possible to clone humans, too.

In 2004, the UK’s human Fertilization and
Embryology Authority (HFEA) gave a Newcastle
biomedical team permission to create human
embryos that are clones to patients. The team is
licensed to use the embryos to make embryonic
stem cells to investigate diabetes, though their
work could be relevant to diseases such as
Alzheimer’s and Parkinson’s

Points in favor of human Cloning

Parents at high risk of producing offspring with genetic
disease would have the opportunity of healthy children

Infertile couples could have children of their own.

Cloning technologies are being developed to deliver
organs for transplants that are entirely compatible and
are not rejected by the recipients immune system.

Cloning techniques are as and reliable as other
comparable medical procedures.

New treatments for genetic diseases are planned and
may shortly be achieved.

Points against human cloning

Human beings might be planned and produced
with the sole intention of supplying ‘spare parts’
for a related human being with some passing
health problem.

Cloning could facilitate ‘improving’ humans by
designing and delivering a race of ‘superior’

Cloning techniques are experimental and
unreliable and unreliable, resulting in the death
of many embryos and newborns, since there are
still so many unknown factors operating.

Points against human cloning

The traditional concept of ‘family’ is of a group of
people with individuality, and with a clear sense
of personal worth.

Clones might have diminished rights and a
lessened sense of individuality.

Some aspects of human life should exist above
the values and standards of the laboratory.

Many believers consider that cloning is against
the will of the god.

Human inventiveness must not tamper with
‘nature’, regarding human
life issues.

Cloning Scientists create human brain cells

Primer on Ethics and Human Cloning

Glenn McGee

An original article


Before cloning is considered permissible medicine for human infertility,
society needs to resolve many questions, including:

Is cloning unnatural self

Will failures, such as deformed offspring, be acceptable?

Will cloning lead to designer babies who are denied an open future?

Who is socially responsible for cloned humans?

Do clones have rights and legal protection

Just Because We Can, Does it Mean We Should?

are finding ways to change information in genes and move these messages to new locations. These
advances can have an impact in science on individuals and to society. As a member of society you should have a
understanding of the benefits and potential harm this technology could lead to. You should also start to form
an educated opinion around these topics.

Choose one of these topic questions and follow the instructions to complete a presentation that will be shared
with the rest of the class. The method of your presentation is up to you: Video, Poster, power point, , other.

Your presentation must include an introduction with background information about your topic and positive and
negative arguments with supporting evidence. You must also include your opinion, for or against, about your
topic with supporting evidence (see the rubric

Should we have the right to know the results of genetic testing?

Should we be able to select the traits to make a perfect baby?

Should we clone extinct species?

Should we be allowed to change our own DNA during our lives?

Should we be able to select against embryos carrying genetic diseases?

Should we clone humans

Rubric will be given



Stephen Taylor

click 4 Biology

IB Biology By Heinemann

IB Biology By C.J. Clegg, IB Biology By


Biology By


Questions and answers about stem cells

4.4.11 Define Clone

A clone is a group of genetically identical
organisms or a group of cells derived from a
single parent cell.

4.4.12outline a technique for cloning using
differentiated animal cell

The technique for cloning using differentiated
cells is mostly somatic cell nuclear transfer
(SCNT) but the use made of the produced cell
can be quite different. Generally reproductive
cloning and therapeutic cloning are discussed

In 1996, a sheep by the name of Dolly
born. She was the first clone whose genetic
material did not originate from an egg cell.

Reproductive cloning of Dolly

Reproductive Cloning

Reproductive cloning creates a new individual. The best
known example is Dolly, the sheep.

The technique used to create Dolly is known as SCNT.

First you take the nucleus from a somatic (body cell). In
the case of Dolly, it was the nucleus from cell in the
udder of her “mother”.

An unfertilized egg was collected from another sheep
and its nucleus was removed.

Using a small and brief electric shock, the egg cell and
the nucleus from the cultured somatic cell were fused


The new cell developed

in a similar way
to a zygote and started to form an embryo

The embryo was placed in the womb of a
surrogate mother sheep.

The embryo developed normally.

Dolly was born, and was presented to the
world as a clone of the original donor sheep.

And with reference to therapeutic cloning the
notes are there in the
previous slides.