Download ppt_E4ch02_Biotechnology_3e

1
Think about…
3.1 What is bioethics?
3.2 Some issues in biotechnology
Recall ‘Think about…’
Summary concept map
2
Following the successful cloning of Dolly
the sheep and other mammals, humans
could possibly be cloned.
3
3.1 What is bioethics?
Bioethics (生物倫理學) is the
study of ethical issues
and implications brought
about by the advances
in the areas of biological
science and medicine.
4
3.1 What is bioethics?
In favour human cloning
Human cloning is a new form
of human reproduction. It
enables infertile couples like
us to have children.
5
3.1 What is bioethics?
In favour human cloning
Our son died in an accident. A
clone of our son may make up
for our loss.
6
3.1 What is bioethics?
human cloning
Against
It is irresponsible to clone
humans when animal cloning
has such a low success rate.
7
3.1 What is bioethics?
human cloning
Against
A clone is neither the child nor
the brother/sister of the nucleus
donor. The identity of the clone
is unclear.
8
3.1 What is bioethics?
• values (價值觀) guide the way
people make their decisions
• values are affected by religion, culture
and past experiences, etc.
• one thing that benefits some people may
not be beneficial to others
9
3.1 What is bioethics?
Bioethics is the study of ethical
issues and implications brought
about by the advances in the areas
of biological science and medicine.
10
3.2 Some issues in
biotechnology
ethical issues
legal issues
social issues
economic issues
environmental issues
11
3.2 Some issues in biotechnology
Genetically modified food
• any food or food ingredient that comes
from genetically modified organisms
(GMOs)
GM tomatoes with
longer shelf life
12
3.2 Some issues in biotechnology
Genetically modified food
1 Safety issues
• long-term effects on
human health?
• new genes or their
products cause allergies?
• transferral of antibiotic resistance
genes produces ‘superbugs’?
13
3.2 Some issues in biotechnology
Genetically modified food
2 Ethical issues
• is it playing God?
• should vegetarians eat
GM plants that contain
animal genes?
14
3.2 Some issues in biotechnology
Genetically modified food
3 Social and economic issues
• increases the dependence of food supply
on developed countries and affects the
living of farmers in developing countries
15
In 1994, genetically modified tomatoes hit the market in
the US as the first commercially available genetically
modified crop. GM tomatoes have since disappeared.
Tomatoes were the first
genetically modified foods
to come on the market.
Today, they are no longer
cultivated.
Puree made from GM
tomatoes was once a
success in Great Britain.
The EU Member States,
however, could not agree
on approval.
16
3.2 Some issues in biotechnology
Genetically modified food
4 Environmental issues
• GMOs may replace the wild types, reduce biodiversity, or upset
the ecological balance
• produces
‘superweeds’
• speeds up the
evolution of
resistant
population of pests
17
Could insect resistance arise
in with BT corn? YES
• Learn about the "refuge" system and
how researchers are manipulating
selective pressures in order to try and
slow the development of Bt-resistant
pests.
• http://www.teachersdomain.org/asset/tdc0
2_vid_btcorn/
18
Refuge field
Insects that feed on the Bt-enhanced plants are continuously exposed to the
lethal Bt toxin, not intermittently exposed, as when Bt is sprayed. The plants kill
most of the insects, but a few bugs will survive because of random mutations
that make them resistant. They'll not only survive, but they'll gain a reproductive
edge, breeding with each other to create strains of Bt-resistant bugs that could
dominate an area.
To forestall this catastrophe, farmers create "refuges" -- fields planted with the
original, non-Bt-modified crops. In these refuges the pests' reproduction will
be free of the selection pressures favoring resistant mutants. The few Btimmune individuals will be overwhelmed by the wild-type, Bt-susceptible
insects. And when the resistant bugs mate with the wild-type individuals, their
offspring will be vulnerable to the Bt toxin.
19
3.2 Some issues in biotechnology
Cloning
• lack of genetic variations
20
3.2 Some issues in biotechnology
Cloning
1 Ethical issues
• low success rate
 death of embryos justified?
% survival
100
implantation
50
0
2 4 6 8 10 12 14 16 18
day of pregnancy
21
3.2 Some issues in biotechnology
Cloning
2 Economic issues
• worth investing the money?
22
3.2 Some issues in biotechnology
Cloning
3 Environmental issues
• clones of endangered animals will still
have no place to live
 spend money on habitat conservation
instead?
23
3.2 Some issues in biotechnology
Cloning
Human reproductive cloning
• clones are ‘unnatural’ ‘sub-humans’?
• relation of the clone with the nucleus
donor and the donor’s family?
• could the clone experience his/her own
life?
• cloning lowers the value of life?
24
3.2 Some issues in biotechnology
Cloning
Human reproductive cloning
Risk of abuse
• what happens if rich people use the
technology to produce servants?
25
3.2 Some issues in biotechnology
Cloning
Human reproductive cloning
Risk of abuse
• what happens if Adolf
Hitler clones himself?
• what happens if someone
allows only the ‘best’
people to be cloned?
26
3.2 Some issues in biotechnology
Human Genome Project
1 Ethical issues
• diagnosis of a genetic disease before
available treatment causes anxiety?
Oh no.
I’m sorry.
There is no
cure for the
disease.
27
3.2 Some issues in biotechnology
Human Genome Project
2 Legal issues
• who can own or gain access to personal
genetic information?
28
3.2 Some issues in biotechnology
Human Genome Project
2 Legal issues
• how can we prevent discrimination
against people with particular genotypes
and misuse of genetic information?
This man has a
high risk of
developing a fatal
genetic disease.
29
3.2 Some issues in biotechnology
Human Genome Project
2 Legal issues
• how can we prevent discrimination
against people with particular genotypes
and misuse of genetic information?
We’d better refuse
his insurance
application.
30
3.2 Some issues in biotechnology
Human Genome Project
2 Legal issues
• can the presence of a certain gene be
used as evidence to prove someone
guilty or innocent?
My client didn’t
do it. His gene
did it.
31
3.2 Some issues in biotechnology
Human Genome Project
3 Social issues
• how is the public perception of an
individual affected by his/her genetic
information?
Go! He has a
gene related to
violence.
32
3.2 Some issues in biotechnology
Human Genome Project
4 Economic issues
• can the same benefits be obtained from
less expensive alternatives?
33
3.2 Some issues in biotechnology
Gene therapy
1 Ethical issues
• when should gene therapy be used?
• acceptable for genetic enhancement?
May I change my eye colour
using gene therapy?
34
3.2 Some issues in biotechnology
Gene therapy
1 Ethical issues
• when should gene therapy be used?
• acceptable for genetic enhancement?
• is it playing God?
• causes unforeseeable harmful effects
on future generations?
35
3.2 Some issues in biotechnology
Gene therapy
2 Legal issues
• how can we obtain
informed consent from
seriously ill patients or
embryos?
• how can we prevent misuse of gene
therapy to produce a ‘perfect’ human
race-- Eugenics?
36
3.2 Some issues in biotechnology
Gene therapy
3 Social issues
• widens the social class gap?
4 Economic issues
• right to invest a large sum of money
for the benefit of a few patients?
• any alternatives?
37
Ethical issues of gene therapy
• Is it right to replace a 'defective' gene with a 'normal' one?
• Is the answer the same for a gene which causes the bearer pain, as it
is where the gene has a merely cosmetic effect?
• Who decides what is 'defective' and what is 'normal'? A 'defective'
gene may actually confer some other advantage, e.g. sickled RBC
gene.
• Is there a danger that we shall in time reduce the variety so
essential to evolution, by the progressive removal of unwanted
genes or, by combining genes from different species, are we actually
increasing variety and favouring evolution?
• Where a gene probe detects a fatal abnormality, what criteria, if any,
should be applied before deciding whether to carry out an abortion?
38
3.2 Some issues in biotechnology
Stem cell therapy
1 Ethical issues
• human embryos are
destroyed to obtain
embryonic stem cells
 murder?
N.B. recent scientific advances may allow production of ES
cells without destroying embryos
39
3.2 Some issues in biotechnology
Stem cell therapy
2 Legal issues
• how can we ensure that the technique
would not be used in human
reproductive cloning?
3 Social issues
• the public become used to the
destruction of human life?
40
1
Why do people disagree on cloning a
whole person? What factors affect their
views on it?
Values guide the way people make
their decision. Values are affected by
religion, culture and past experiences,
etc.
41
1
Why do people disagree on cloning a
whole person? What factors affect their
views on it?
In addition, one thing that benefits
some people may not be beneficial to
others. Thus, people may disagree on
cloning a whole person.
42
2
Do you support the cloning of a
whole person? Why?
Answers vary with students.
43
Bioethics
study of ethical issues and
implications brought about by
the advances in the areas of
biological science
and medicine
includes
biotechnology
44
biotechnology
raises
ethical
issues
legal
issues
social
issues
economic
issues
environmental
issues
45