Trial Version
Science and Technology
The Nature and Development of Science and Technology
Case investigation – The important developments of science and
technology
Case 3: Biotechnology
Activity and case-based learning & teaching resources
Students’ version
Table of Content (Students’ version)
Outline
Aims of study
Scheme of work
Background information
2
2
3
Teaching Resources
Lesson 1, 2: What is biotechnology?
Background
Activity 1: Information collection and poster design
Reference article
Activity 2: “KARS” game <infectious diseases and biotechnology>
Worksheet
Additional background information
4
4
5
5-6
7
7
8 - 14
Lesson 3, 4: Development of modern biotechnology
Background
Activity 3: DNA extraction experiment
Additional background information
15
15
16- 18
19- 23
Lesson 5, 6: What are the problems of biotechnology?
24
Background
24
Activity 4: Debate on the constraints and controversies on biotechnology 25-31
(Discussion questions and articles)
Worksheet
32
Extended activities and readings
33-37
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Students’ version
Outline
Aims of study
The aim of these lessons is to introduce biotechnology - a rapidly developing knowledge and
technology that affects human living in various aspects. Students should have a brief
understanding on the development of biotechnology through the lessons.
The course will motivate their interest to observe biotechnology through their daily lives, as
well as to take part in some discussions about the development of biotechnology. Students have
to find out the contributions of biotechnology from its history and constraints through ethical and
safety issues. Through the group activities, students are encouraged to exchange ideas with each
other, so as to have a better understanding on the strengths and constraints of technological
development.
Scheme of work
Lessons
Learning objective
1, 2

What is
biotechnology?
Teaching strategy




3, 4

The development
of modern
biotechnology


5, 6

What are the
problems of
biotechnology?

Learning and
teaching resources
Brief explanation of the  PowerPoint
definition and examples of  Fluorescent
biotechnology
pigments
Brief explanation of the  Worksheet
milestone of
biotechnology I
Information collection of
biotechnology topics
“KARS” game
Brief explanation of the
milestone of
biotechnology II
DNA extraction
experiment
Debate on the constraints
and the issues of
biotechnology






PowerPoint
Experimental
apparatus/
materials
Worksheet
PowerPoint
Articles and
debate topics
Worksheet
2
Students’ version
Background information
Biotechnology is one of the most rapidly developing technologies in the world. The
increasing popularity of modern biotechnology can be traced back to the 1970s when genetic
researches have become mature that brought about a developmental breakthrough. In fact,
biotechnology has had a close relationship with the human society long ago. From the examples
of the Babylonian’s beer in 6000 B.C. and the Egyptian’s baked cakes in 4000 B.C., we can
convince that humans have started to observe the new elements evolved from the changes of
natural substances and from the life process of organisms during the ancient time. Although the
ancient people cannot master the scientific principles yet, they can make use of their limited
knowledge to fulfil the needs of their daily lives.
Nowadays scientists have done biological researches widely and deeply, which decode lots
of myths of lives. With the rapid development of electronics and engineering technology, the
application of biotechnology is versatile and far-reaching. Even though the development of
modern biotechnology has undergone just more than 20 years, its applications extend over
different areas included the major problems of food, health, resources, energy and environment
that humans are facing.
Biotechnology is closely related to our lives and has a close relationship with our personal
health. The antibiotics used for fighting against bacteria, vaccine inoculation and drugs produced
from researches on molecular structures are all beneficial to our health.
The rapid development of biotechnology continually not only brings novel technological
breakthrough to humans, it also causes great impacts on ethics and in aspects of life and death.
For example, the controversies on ‘animal cloning’ and ‘human cloning’ in the recent ten years as
well as the discussions on researches of embryonic stem cells and gene therapy, all of which lead
people from different sectors to have self-reflection on the problems of life, morality and ethics.
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Students’ version
Teaching Resources
Lesson 1, 2: What is biotechnology?
Background
Although the relationship between biotechnology and us is very close, we may not be aware
of what it is and how does it operate? How can we observe its footprint in our lives? What are its
contributions and constraints?
Biotechnology included two words, Bio (lives and organisms) and Technology (crafts and
techniques). Simply speaking, the meaning of the whole term is ‘the techniques to use organisms
to produce products’. However, the scope of this definition is very wide. For a more precise
description, “biotechnology” is ‘the techniques applying biological process, biological cells or
other metabolites to produce products and improve the quality of human living’.
The application of biotechnology is very widespread and the related area is expending
continually. Conventional biotechnology can be divided into three areas to be applied in
agriculture, medicine and industry. Nowadays, the applications of biotechnology are even wider
in chemical industry and environmental protection, resources and energy, marine resources
exploitation and even in military development. Moreover, biotechnology has become the basic
tool for investigating life science researches in academic researches. Modern biotechnology is
flourishingly developing worldwide and are recognised as the most important industry in the 21st
century.
Activity 1: Information collection
〈Investigating biotechnology aspect〉
Activity guideline:
Students are divided into 5 groups to collect information of each aspect and design a
poster using the information as examples.
The poster designed should be suitable for teaching and commercial purposes. The
objective is to introduce new knowledge to readers and let them clearly understand the basic
ideas of the chosen aspect. For examples, its developmental history, application, advantages,
constraints and the ethical, legal and regulation problems, etc.
Biotechnological areas
Examples
Medical
Agricultural
Environmental
Military defences
Scientific researches
Student can start from some examples in their daily lives to design the poster. For example
in the medical application of biotechnology, students might have taken antibiotics. Students
can also try to collect information from different areas such as the basic function of
antibiotics, the contribution of biotechnology and the invention of antibiotics, its
applications and demands in the past and present and the problems induced by it such as
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Students’ version
drug abuse, etc.
Reference article:
http://www.nal.usda.gov/bic/bio21/execsum.html
Biotechnology for the 21st Century: New Horizons
Preface
Through the use of advanced tools such as genetic engineering, biotechnology is
expected to have a dramatic effect on the world economy over the next decade.
Innovations emerging in the food and pharmaceutical sectors offer only a hint of the
enormous potential of biotechnology to provide diverse new products, including
disease-resistant plants, "natural" pesticides, environmental remediation technologies,
biodegradable plastics, novel therapeutic agents, and chemicals and enzymes that will
reduce the cost and improve the efficiency of industrial processes.
To date, the Federal investment in biotechnology has been focused primarily on the
health field. The results of this research are having a profound impact on medicine and
health care, providing improved approaches to the diagnosis, treatment, and prevention of
disease. While health-related research must remain a national priority, researchers are
poised to build on the common foundation in basic science to bring the power of
biotechnology to bear in other fields. Modest investments now in several rapidly
developing areas of biotechnology research will lead to major economic and societal
benefits, including foods that are more abundant and nutritious, a cleaner environment,
and non- toxic biomanufacturing.
This "second wave" of biotechnology research is the focus of this report, which is
the result of a planning effort by the Biotechnology Research Subcommittee (BRS) of the
Committee on Fundamental Science of the National Science and Technology Council
(NSTC). The report outlines opportunities for Federal investment in research in four
areas: (1) agricultural biotechnology; (2) environmental biotechnology, with a focus on
bioremediation, (3) manufacturing/bioprocessing, including energy research; and (4)
marine biotechnology and aquaculture. The plans were developed with input from the
private sector.
Following is a summary of the priorities identified in each area:
Agriculture
Agricultural biotechnology offers efficient and cost-effective means to produce a diverse
array of novel, value-added products and tools. It has the potential to increase food
production, reduce the dependency of agriculture on chemicals, and lower the cost of raw
materials, all in an environmentally friendly manner.
Environment
The focus in environmental biotechnology is on bioremediation. This involves the use of
living organisms or their products to degrade wastes into less toxic or non-toxic products
and to concentrate and immobilize toxic elements, such as heavy metals, to minimize
industrial wastes and rehabilitate areas fouled by pollutants or otherwise damaged
through ecosystem mismanagement.
Manufacturing/Bioprocessing
The demand for new and improved commercial products increasingly will be met through
bioprocessing, a type of advanced manufacturing that employs chemical, physical, and
biological processes employed by living organisms or their cellular components.
Bioprocessing can provide products with unique and highly desirable characteristics and
offers new production opportunities for a wide range of items.
Marine Biotechnology and Aquaculture
Oceanic organisms constitute a major portion of the Earth's biological resources, yet most
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Students’ version
of these organisms (primarily microorganisms) have yet to be identified. Recent advances
in molecular biology, biosensor technology, aquaculture, and bioprocess engineering now
promise fundamentally new approaches and opportunities for identifying, using, and
managing biological resources from the seas.
Biotechnology is poised to make major contributions to the economic growth of the
United States and the world in the 21st century. Coordinated implementation of these
priorities will enable the United States to retain its pre-eminence in this burgeoning field.
A Report from the Biotechnology Research Subcommittee
Committee on Fundamental Science
National Science and Technology Council
July 1995
Please answer the questions below:
1. Please list the biotechnological areas mentioned in the article：
＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿
＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿
＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿
2. As mentioned in the article, techniques of medical biotechnology greatly improved the
preventative, diagnosis and therapeutic methods of diseases, which give significant
influence to human health. Can you observe any related examples in your daily lives?
＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿
＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿
＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿
3. In the article, the great contribution of environmental biotechnology in processing
pollutants has been mentioned. Can students think of another issues about
environmental ecology? How can biotechnology assist in solving this problem?
＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿
＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿
＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿
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Students’ version
Activity 2: “KARS” game
〈Infectious diseases and biotechnology〉
Infectious diseases have long been human killers. At the end of the 16th century,
people invented microscopes, which enable us to observe cells, tissues and
microorganisms, which cannot be observed by naked eyes. As scientists could
observe the living phenomenon of bacteria, they could understand the causes of
illnesses and it helps in diagnosing and curing diseases – it is an extremely
important breakthrough in biology. Electronic microscopes were invented in
1930s, scientists were then able to observe viruses, which could not be seen
before.
We hope the simple game can inspire students thinking about the risk of infectious
diseases and their relationship with biotechnology.
Please group the infectious diseases below and choose the names of bacterial
transmitted diseases, such as cholera, to fill in the appropriate boxes.
Tuberculosis
AIDS
Measles
Influenza
Syphilis
SARS
Bacterial cases
Hepatitis
Meningitis
Bird flu
Cholera
Chicken pox
Tetanus
Viral cases
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Students’ version
Additional background information：
Summary of the history of the development of biotechnology
BC 6000 Barbarians used yeast to brew beer
4000 Egyptians used yeast to bake bread
AD 1590 H. Janssen and Z. Janssen invented compound microscope
1683 A.V. Leeuwenhoek observed bacteria
1796 E. Jenner discovered cowpox patients were immune to small pox and developed
cowpox vaccines to prevent small pox infection.
1865 G. Mendel discovered basic materials of inheritance and established the
foundations of genetic studies
1868 J. Miescher discovered DNA
1879 W. Fleming discovered chromosomes
1910 T. H. Morgan proved that chromosome exists in inherited genes. He was awarded
the Nobel Prize (physiology or medicine) in 1933
1928 A. Fleming conducted researches on antibiotics (Penicillin)
1944 O. Avery and his colleagues proved that genetic materials exist in DNA but not in
proteins. Scientists started to have intensive researches on DNA.
1953 J. Watson and F. Crick discovered the double-helix structure of DNA. In 1962 ,
Crick and Watson awarded the Nobel Prize (Physiology or Medicine)。
1957 F. Crick explained how different proteins are produced from DNA
1969 J. Beckwith and J. Shapiro, et al. isolated genes for the first time
1970 H.O. Smith and K.W. Wilcox discovered restriction enzymes which can
selectively break the DNA strand (Restriction enzyme)。
1972 Paul Berg used restriction enzymes to break DNA into fragments, then used
ligase to join two segments of DNA. DNA recombination succeeded. Paul
Bergwon was awarded the Nobel Prize (Chemistry) in 1980
1973 S. Cohen and H. Boyer used the techniques of cutting and pasting DNA for DNA
recombination to produce DNA recombinants. Recombinant DNA characterised
the commence of biotechnology
1983 K. B. Mullis invented Polymerase Chain Reaction (PCR) to simultaneously copy
and replicate large amount of DNA in a short time, which is an important method
for biotechnology researches. Mullis won the Nobel Prize (Chemistry) in 1993.
1984 DNA Fingerprinting started to be applied in crime investigation
1990 HGP - Human Genome Project launched
1996 The first cloned sheep in the world, Dolly was born
1998 Human Embryonic stem cells (HESC) were successfully cultivated by J. Gearhart
and J. Thomson
2003 HGP finished and released the 3 billion of base pairs sequence in human genome
in the science magazine <Nature>
2005 The Genographic Project。
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Students’ version
Additional background information：
Summary of biotechnological development – case investigation
Polymerase Chain Reaction (PCR) (Extract)
http://en.wikipedia.org/wiki/Polymerase_chain_reaction
From Wikipedia
What is PCR?
Polymerase chain reaction (PCR) is a molecular biology technique, for enzymatically
replicating DNA without using a living organism, such as E. coli or yeast. Like amplification
using living organisms, the technique allows a small amount of the DNA molecule to be
amplified exponentially. However, because it is an in vitro technique, it can be performed without
restrictions on the form of DNA and it can be extensively modified to perform a wide array of
genetic manipulations.
The applications of PCR: PCR is commonly used in medical and biological research labs for a
variety of tasks, such as the detection of hereditary diseases, the identification of genetic
fingerprints, the diagnosis of infectious diseases, the cloning of genes, paternity testing, and DNA
computing.
PCR can be used for a broad variety of experiments and analyses. Some examples are discussed
below.
Genetic fingerprinting
Genetic fingerprinting is a forensic technique used to identify a person by comparing his or her
DNA with a given sample, such as blood from a crime scene can be genetically compared to
blood from a suspect. The sample may contain only a tiny amount of DNA, obtained from a
source such as blood, semen, saliva, hair, or other organic material.
Paternity testing
A paternity test is conducted to prove paternity, that is, whether a man is the biological father of
another individual. This may be relevant in view of rights and duties of the father. Similarly, a
maternity test can be carried out. This is less common, because at least during childbirth, except
in the case of a pregnancy involving embryo transfer or egg donation, it is obvious who the
mother is.
This can be achieved by DNA analysis of the three individuals, although older methods have
included ABO blood group typing, analysis of various other proteins and enzymes, or using HLA
antigens. For the most part however, DNA has all but taken over all the other forms of testing.
Detection of hereditary diseases
The detection of hereditary diseases in a given genome is a long and difficult process, which can
be shortened significantly by using PCR. Each gene in question can easily be amplified through
PCR by using the appropriate primers and then sequenced to detect mutations.
Cloning genes
Cloning a gene, not to be confused with cloning a whole organism, describes the process of
isolating a gene from one organism and then inserting it into another organism (now termed a
genetically modified organism (GMO)).
Mutagenesis
Mutagenesis is a way of making changes to the sequence of nucleotides in the DNA.
Analysis of ancient DNA
Using PCR, it becomes possible to analyze DNA that is thousands of years old.
PCR is an important technique in biotechnology and medicine, and its role would be more
essential in the future.
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Students’ version
Human Genome Project (1990-2003) (Extract)
http://en.wikipedia.org/wiki/HGP
From Wikipedia
The Human Genome Project (HGP) is a project to map and sequence the 3 billion nucleotides
contained in the human genome and to identify all the genes present in it.
Goals
The goals of the original HGP were not only to determine all 3 billion base pairs in the human
genome with a minimal error rate, but also to identify all the genes in this vast amount of data.
This part of the project is still ongoing although a preliminary count indicates about 30,000 genes
in the human genome, which is far fewer than predicted by most scientists.
Another goal of the HGP was to develop faster, more efficient methods for DNA sequencing and
sequence analysis and the transfer of these technologies to industry.
The sequence of the human DNA is stored in databases available to anyone on the Internet. The
U.S. National Center for Biotechnology Information (and sister organizations in Europe and
Japan) house the gene sequence in a database known as Genbank, along with sequences of known
and hypothetical genes and proteins. Other organizations such as the University of California,
Santa Cruz, and ENSEMBL present additional data and annotation and powerful tools for
visualizing and searching it. Computer programs have been developed to analyze the data,
because the data themselves are difficult to interpret without them.
The process of identifying the boundaries between genes and other features in raw DNA
sequence is called genome annotation and is the domain of bioinformatics. While expert
biologists make the best annotators, their work proceeds slowly, and computer programs are
increasingly used to meet the high-throughput demands of genome sequencing projects. The best
current technologies for annotation make use of statistical models that take advantage of parallels
between DNA sequences and human language, using concepts from computer science such as
formal grammars.
Another, often overlooked, goal of the HGP is the study of its ethical, legal, and social
implications. It is important to research these issues and find the most appropriate solutions
before they become large dilemmas whose effect will manifest in the form of major political
concerns.
All humans have unique gene sequences, therefore the data published by the HGP does not
represent the exact sequence of each and every individual's genome. It is the combined genome
of a small number of anonymous donors. The HGP genome is a scaffold for future work in
identifying differences between individuals. Most of the current effort in identifying differences
between individuals involves single nucleotide polymorphisms and the HapMap.
Benefits
The work on interpretation of genome data is still in its initial stages. It is anticipated that detailed
knowledge of the human genome will provide new avenues for advances in medicine and
biotechnology. Clear practical results of the project emerged even before the work was finished.
For example, a number of companies, such as Myriad Genetics started offering easy ways to
administer genetic tests that can show predisposition to a variety of illnesses, including breast
cancer, disorders of hemostasis, cystic fibrosis, liver diseases and many others. Also, the
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Students’ version
etiologies for cancers, Alzheimer's disease and other areas of clinical interest are considered
likely to benefit from genome information and possibly may lead in the long term to significant
advances in their management.
There are also many tangible benefits for biological scientists. For example, a researcher
investigating a certain form of cancer may have narrowed down his search to a particular gene.
By visiting the human genome database on the worldwide web, this researcher can examine what
other scientists have written about this gene, including (potentially) the three-dimensional
structure of its product, its function(s), its evolutionary relationships to other human genes, or to
genes in mice or yeast or fruit flies, possible detrimental mutations, interactions with other genes,
body tissues in which this gene is activated, diseases associated with this gene or other datatypes.
Further, deeper understanding of the disease processes at the level of molecular biology may
determine new therapeutic procedures. Given the established importance of DNA in molecular
biology and its central role in determining the fundamental operation of cellular processes, it is
likely that expanded knowledge in this area will facilitate medical advances in numerous areas of
clinical interest that may not have been possible without them.
The analysis of similarities between DNA sequences from different organisms is also opening
new avenues in the study of the theory of evolution. In many cases, evolutionary questions can
now be framed in terms of molecular biology; indeed, many major evolutionary milestones (the
emergence of the ribosome and organelles, the development of embryos with body plans, the
vertebrate immune system) can be related to the molecular level. Many questions about the
similarities and differences between humans and our closest relatives (the primates, and indeed
the other mammals) are expected to be illuminated by the data from this project.
The Human Genome Diversity Project, spinoff research aimed at mapping the DNA that varies
between human ethnic groups, which was rumored to have been halted, actually did continue and
to date has yielded new conclusions. In the future, HGDP could possibly expose new data in
disease surveillance, human development and anthropology. HGDP could unlock secrets behind
and create new strategies for managing the vulnerability of ethnic groups to certain diseases (see
race in biomedicine). It could also show how human populations have adapted to these
vulnerabilities.
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Students’ version
Additional background information:
DNA project to trace human steps (The Genographic Project – 2005) (Extract)
http://news.bbc.co.uk/1/hi/sci/4435009.stm
By Paul Rincon
BBC News science reporter
A project spanning five continents is aiming to map the history of human migration via
DNA.
The Genographic Project will collect DNA samples from over 100,000 people worldwide to help
piece together a picture of how the Earth was colonized. Samples gathered from indigenous
people and the general public would be subjected to lab and computer analysis to extract the
valuable genetic data. Team leader Dr Spencer Wells calls the plan "the Moon shot of
anthropology".
The $40m (£21m) privately funded initiative is collaboration between National Geographic, IBM
and the Waitt Family Foundation charity. Participating in the five-year study are some of the
world's top population geneticists, as well as leading experts in the fields of ancient DNA,
linguistics and archaeology.
Future resource
"We see this as a resource for humanity going into the future. It could potentially become the
largest genetic database ever created," Dr Wells told the BBC News website.
Members of the public will be able to buy a kit that contains all the material needed to add their
genetic information to the database. Already, evidence from genetics and archaeology places the
origin of modern humans (Homo sapiens) in Africa roughly 200,000 years ago. It is thought, the
first moderns to leave the continent set off around 60,000 years ago.
By studying the Y (or male) chromosome and mitochondrial DNA (which is passed down
exclusively on the maternal line), scientists have pieced together a broad-brush picture of which
populations moved where in the world - and when.
What is lacking, says Wells, is the fine detail, which could be filled in by this large-scale project.
"We know which markers on the Y chromosome to focus on; we know our way around the
mitochondrial genome fairly well. We just haven't had the large sample sizes to apply these
technologies properly," Dr Wells explained.
"There are still many questions we haven't answered. Was there any interbreeding with
Neanderthals as modern humans moved into Europe? Did any of the migrations to the Americas
come across the Pacific - or even the Atlantic?"
Collection challenge
But some researchers said experience on other projects suggested this one could run into trouble
with indigenous groups - particularly those, such as Native Americans and Aboriginal
Australians, with a history of exploitation. Project directors said they had already sought advice
from indigenous leaders about their participation.
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Students’ version
IBM says it will use sophisticated analytical techniques to interpret the information in the
biobank and find patterns in the genetic data. The IT giant will also provide the computing
infrastructure for the project. Kits sold to the public contain cheek swabs used to scrape the inside
of the mouth for a DNA sample. The swabs can then be mailed to a central laboratory for
analysis. After four to six weeks, the results of the analysis will appear on the website behind an
anonymous password contained in the kit.
The exact budget available for the study will depend on how many test kits are sold to the public.
The net proceeds will go back into the research and into a "legacy project" to support indigenous
peoples.
The Genographic Project's directors emphasize that the information in the database will be made
accessible to scientists studying human migrations. "We see this as part of the commons of our
species. We're not going to be patenting anything - the information will all be in the public
domain," said Dr Wells.
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Students’ version
Additional background information:
Bacteria and viral cells under microscope：
HIV virus (AIDS)
Bacilli (Vibrio cholerae)
Poliovirus (Poliomyelitis)
Spirillum
Source of figures：
http://virology-online.com/presentations/index.htm
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Students’ version
Lesson 3,4: The development of modern
biotechnology
Background
Biotechnology is not entirely an emerging technology. Traditional biotechnology can be
traced back to the fermentation process used by ancient people to produce traditional food such
as rice wine, vinegar, soya sauce and bread, etc. Meanwhile, modern biotechnology as an
emerging discipline with the development of genetic engineering as the core, it is based on
researchresults of modern biology from late 1970s to early 1980s. It allows people to modify the
form and structure according to their default setting or to process raw biological materials for
producing products and achieving some technical requirements.
Although the hallmark of modern biotechnology is DNA recombination technology in the
1970s, this kind of technology is established from the results of conventional Biology and other
disciplines, as well as the previous research outcomes on engineering technologies. The keys
included the claim made by Oswald T. Avery, et al. in 1944 that DNA is the carrier of inheritance
messages and the discovery of double helix DNA structure by James Watson and Francis Crick in
1953 that led to the later molecular biology researches. Since all living activities are the results of
the functioning of enzymes and non-enzymatic proteins, the relationship between inheritance
messages and proteins has become the key theme of investigating living activities. In 1961,
Marshall Nirenberg explained how do the inheritance messages in DNA coding (A, T, G, C)
transmit to proteins.
In 1972, Paul Berg became the first expert of biological researches to accomplish the in vitro
DNA recombination techniques successfully based on the results of the academic researches
above. We can break up DNA strands, isolate and recombine the genes for inoculating into other
organism and reconstructing cells now according to what we want. Use the simple organisms
bacteria as an example, enormous amount of functional proteins used for drug and vaccine
production are produced. These modified bacteria can even be injected into human body directly
for gene therapy. In 1983, a scientist, Kary Mullis invented Polymerase Chain Reaction (PCR) to
copy a DNA fragment to 10 billions to 100 billions times. This is a technique having great impact
on biology and medicine as well as forensic science.
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Students’ version
Activity 3: DNA extraction experiment
Guidelines: As time for the experiment is limited, teacher should ask the laboratory
technicians to prepare suitable apparatus and tools before the experiment to ensure effective
time-management.
Materials
Kiwi fruit
3 g sodium chloride
(salt)
100 ml distilled
water
10 ml detergent
Egg white
Chilled pure alcohol
60℃ hot water
Iced water
Apparatus
Beaker
Filter paper
100 ml measuring
cylinder
Large test-tube
Blender
Glass rod
Thermometer
Dropper
Step 1: Preparation
Pour 3 g of sodium chloride (salt) and 10 ml of detergent into beaker with 100 ml distilled
water. Slice the Kiwi fruit into small pieces and immerse it into the detergent-salt liquid.
Step 2: Soak in hot water
Put the beaker with the liquid above in a water bath of 60℃ for 15 minutes and stir it gently
(Figure 1).
(Figure 1)
(Figure 2)
Step 3: Immersing in iced-water
Put the beaker with the liquid in iced water bath for 5 minutes and stir it gently (Figure 2).
Step 4: Blending
Pick up the beaker and pour the liquid into the blender to blend for 5 seconds, and then filter
the mixture (Figure 3).
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Students’ version
(Figure 3)
Step 5: Filtration:
Collection about 6 ml filtrate by test-tube and add 4 drops of egg white (Figure 4).
(Figure 4)
Step 6: Extraction
Pour the chilled alcohol via the wall of the test-tube to the surface of filtrate slowly. (A milky
layer will be formed between the upper layer of alcohol and the lower layer of detergent
(Figure 5))
Use dropper to extract the milky substance in the layer and use universal indicator to test the
pH value of the gene extract.
Alcohol
Kiwi DNA
Detergent
(Figure 5)
Result
The layer of milky substance is the extracted DNA. Since DNA is acidic, the test result is: the
universal indicator changed from green to orange-yellow.
Advanced activity
(1) Use dye to stain DNA, then observe it under microscope
(2) The gene extraction method of other biological tissues is similar to the proposed method
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Students’ version
above, students can try to extract gene from animal’s liver or that from microorganism.
Safety rules
Beware of safety when cutting or using blender.
(Modified from the web site of “Promoting biotechnology education” by the Science Faculty
of HKIED)
http://www.ied.edu.hk/biotech/chi/exp/exp_onion2.htm
Explanation of experiment:
All the chemicals used in this experiment can help us to extract DNA from cells. Firstly,
the cell walls have to be broken down. The cleaning detergent lead to burst of the outer part
of cells and salts can assist in separating DNA and other molecules such as carbohydrates.
Cooling can prevent the DNA remained in membranes and of cell nucleus to be digested by
enzymes as the activity of enzymes digesting DNA are reduced in lower temperature. After
removing unnecessary substances in the mixture by filtration, DNA material would become
harder and precipitated after the liquid is cooled down.
Please answer the questions below:
1. Do you understand the effect of different chemicals in the experiment? For examples,
why do we add detergent into the Kiwi fruit?
＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿
＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿
2. Why does alcohol ‘float’ on the water in step 6? What is the use of alcohol in the
experiment?
＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿
＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿
3. How important is the technique to extract DNA from organisms?
＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿
＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿
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Students’ version
Additional background information:
Basic vocabularies of life science
Cells
Cells are the most basic unit of lives. All of the organisms are composed of and constructed by
cells. Some cells exist in single and some cells exist in groups. Human cells can be divided into
two parts: cell nuclei and cytoplasm. Cells can absorb water and food for keeping alive, they can
also synthesize human tissues and organs.
DNA
DNA is the abbreviation deoxyribonucleic acid, which is the basic unit of organism inheritance.
DNA can be linked into a long molecule and compose chromosome. DNA exists in the cell
nucleus to control all cellular activities. DNA comprises of a sugar (deoxyribose), a phosphate
and nitrogenous bases forming a double-helix structure. Its base pair sequence arrangement is an
essential factor to determine biological characteristics. There are four kinds of nitrogenous bases
and the DNA sequence is the characterised arrangement method to pair these bases.
Genome
Genome is the entire DNA combination of an organism.
Gene
Gene is the specified DNA sequence, which contains codes to direct the protein production of
body and catalyse the biochemical reactions in the body.
Protein
Protein is the main cell structure, which carry out almost all the functions in the human body to
maintain life. Protein is a polymer from combination of amino acids.
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Students’ version
Additional background information:
DNA、RNA and proteins
The basic principle of molecular biology is producing RNA from DNA, producing proteins from
RNA, then producing different cells from different proteins and finally forming human body by
enormous cells. As a result, the most basic life message is encoded in 3 billion DNA codes at the
nucleus of the cell. You can completely understand what human being is once you have decoded
the “human barcode” with that enormous figure.
DNA molecules are often in double helix structures of 4 nucleobase A, T, G and C. When
molecular biologists doing researches, they usually list the DNA sequence of one of the double
strands. It is because you can predict the other strand by the DNA sequence of its pairing strand.
When it is G at one side, the other side must be C and A must pair with T. As a result, molecular
biology experts would only mention one strand when discussing about DNA even though it is
actually a double helix.
DNA and protein
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Students’ version
Additional background information:
Modern bioengineering
Biotechnology, which is also known as Bioengineering, indicates using modern biological
science as the basis and combining different types of advanced engineering techniques and the
scientific principles to design and modify organisms or process raw biological materials. It can
produce different products according to human needs or achieve certain purposes in biochemical
processes.
The evolvement and development of bioengineering are related to many different disciplines,
included molecular biotechnology, microbiology, genetics, cytology and biochemistry, etc.
meanwhile it is also a system of technologies incorporating series of techniques including genetic
engineering, cellular engineering, enzymatic engineering, protein engineering, fermentation
engineering and biochemical engineering.
Genetic engineering
Genetic engineering is mainly the gene recombination technique. The development of genetic
engineering is based on molecular biology. In 1953, Watson and Crick discovered the double
helix structure of DNA. The success of gene recombination experiment in the 1970s leads to the
evolvement of rapid development of genetic engineering.
The basic techniques of genetic engineering is to apply different functional enzymes to cut and
paste genes and for expression. We should first understand the structure, organisation, adjustment,
control and function of genes, so as to recognize the growth and development, separation of
organisms, the inheritance alternation of species and evolutionary pattern accurately. The above
practises supply new materials, techniques and methods for the genetic engineering techniques.
Cellular engineering
Cellular engineering is closely related to genetic engineering and the major concern of cellular
engineering is culturing of cells. Cellular culturing in a great scale can be divided into three
levels, single cellular culturing, tissue culturing and organ culturing. Culturing techniques of
plant cells and the protoplast may use in breeding, in accelerating the reproduction rate of plants
and raising non-toxic seedling, seeds for long-term storage and on production of secondary
metabolites. The culturing techniques used in animal cells culturing can make many cell products
with application values like vaccine and growth gene. Drug and medicine monitoring can also be
carried out using cell-culturing system. Some cultured cells can even be applied for therapy. In
addition to cell culturing, the applications of cellular engineering also included cell fusion, cell
conversion, chromosome operation and gene transfer, etc.
Enzymatic engineering
Enzyme is protein catalyst, which is also regarded as ‘promoters’ of organisms’ living activities.
That is why it is the core of genetic engineering. Without the function of enzymes, no
biotechnology techniques can be realised. Enzymatic engineering is making use of the catalytic
activity of enzymes to convert some raw materials into useful substances. In its industrial and
medical applications, its catalytic function has played an extremely important role. The laundry
cleaner that we used in our daily lives is a good example of industrial application of enzymes.
Protein engineering
Protein is one of the most special substances among those in constructing an organism. It has a
complex structure and various functions and it plays an important role in organisms, such as the
conversion of nutrients, control of growth and differentiation, and oxygen transport actions, etc.
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Students’ version
Scientists discovered that the structure of protein is closely related to its function. The main
purpose of protein engineering is to investigate the relationship between protein structure and
function by generating ‘point mutation’ accompanying with recombinant DNA and synthetic
DNA techniques. It allows researchers to have a deeper understanding of the phenomenon and
evolution of lives.
Fermentation engineering
Fermentation was originated from the Latin word（fervere）, which indicates the yeast reaction in
fruit juice and budding cereals to produce carbon dioxide. Pasteur has examined the physiological
meaning of alcohol fermentation and claimed it is the result of anaerobic respiration of the yeast,
the yeast without oxygen supply. The biochemical definition of fermentation is “the metabolic
process that microorganisms carry out in the absence of oxygen”. Nowadays, people use
‘fermentation’ to characterise the application of the life activity of microorganisms under aerobic
or anaerobic conditioner to produce microbial fungi and its metabolites.
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Students’ version
Additional background information:
Important equipment and facilities for modern biotechnology
All the biotechnology areas must apply a large amount of modern precise equipments such as
ultra speed centrifugal machine, electronic microscope, high efficiency liquid chromatography,
DNA synthesizer and DNA sequence analyser, etc. All of these equipment is controlled by
microcomputers and fully-automatic. The modern biotechnology nowadays relies on the
integration of the modern microelectronic and computer technology techniques and
biotechnology techniques.
Important apparatus and equipments for modern biotechnology
Name
1. Automatic DNA sequence analyzer
2. Biological reactor
3. Real Time PCR
4. Gel electrophoresis system
5. Ultra speed/ High speed centrifugal
machine
6. Electronic microscope
Function
Automatically analyse nucleic acid
and nucleotide sequence
Continuously culturing of cells
Rapid DNA replication
Separation and analysis of protein and
Nucleic acid
Separating large molecular substances
of organisms
Observe microstructure of cells and
tissues
Result of electrophoresis gel
Source：CashmereBiotech-Taiwan
Human DNA under electronic microscope
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Students’ version
Lesson 5, 6 ： What are the problems of
biotechnology?
Background
Modern biotechnology development is thriving, which
undoubtedly contributes to medical, food and environment protection
areas in the human society. However, the fast development of
biotechnology is similar to other technologies that undergo a lot of
constraints. The application of biotechnology often leads to
controversial debates on ethical, moral and legal viewpoints.
Source：Scientific American
Through the continually developing and modifying
biotechnology techniques, scientists have already mastered the
animal cloning techniques. The first cloned animal in the world,
Dolly the Sheep, was born in Scotland in 1996. Lots of scientists
followed the research and ‘cloned rhesus’, ‘cloned cow’, ‘cloned
mouse’ and’ cloned dog’ started to appear successively. It should be
noticed that ‘cloned human’ will appear in the days to come, and it
would lead to worrying problems in ethical aspects.
The success of embryonic stem cell research signified the new hopes to cure serious
illnesses, however, the embryo cloning techniques also brings a difficult question to us, which is
related to the nature of life. We may ask ‘Is the cloned embryo a human being? Should the
embryonic stem cell be treated as life? When do we start to count for a life begins?’
Human Genome Project was completed in 2003. The purpose was to figure out the gene
map including the whole set of human inheritance code. It brings together the computer
hardwares and softwares to decode and analyse DNA code and gene function of human. The
technique can even be developed into a DNA database, which is comparable, that of fingerprints.
However, establishing DNA database would lead to sensitive problems such as privacy and ‘gene
discrimination’. What kind of attitudes should we have for building up DNA databases in
hospitals or schools in the nation?
Recently, there is another biotechnological issue that attracts lots of interest, it is about the
novel medical techniques ‘Gene therapy’. Conceptually, ‘gene therapy’ can give hopes to cure
lots of serious genetic diseases. However, scientists still cannot master all of the theories in gene
technology at the moment and have limited ideas on the related side effects induced by gene
therapy, further investigations are needed to be carried out. Since gene therapy may lead to
unpredictable danger to patients, legal and social problems including risk of medical treatment
and the liability would be found.
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Students’ version
Activity 4: Group debating
Students are divided into groups of 4 people and choose one of the two issues below to discuss.
Each group should also choose to support or oppose the notion. Please refer to the related articles
and prepare your debating scripts after collecting further information.
Two issues included: 1. Cloning lives; 2. Embryonic stem cells research
Issue 1. Cloning lives
Please read the article below as debating information
<Reference article 1>
All the Reasons to Clone Human Beings (Extract)
http://www.humancloning.org/allthe.php
Simon Smith
Medical breakthroughs - Human cloning technology is expected to result in several miraculous
medical breakthroughs. We may be able to cure cancer if cloning leads to a better
understanding of cell differentiation. Theories exist about how cloning may lead to a cure for
heart attacks, a revolution in cosmetic surgery, organs for organ transplantation, and predictions
abound about how cloning technology will save thousands of lives.
Medical tragedies - Many people have suffered accidental medical tragedies during their
lifetimes. Read about a girl who needs a kidney, a burn victim, a girl born with cosmetic
deformities, a man who needs a liver, a woman who is infertile because of cancer, and a father
who lost his only son. All these people favour cloning and want the science to proceed.
To cure infertility - Infertile people are discriminated against. Men are made to feel like they
are not "real men." Women are made to feel as if they are useless barren vessels. Worse, being
infertile is often not considered a "real medical problem" and insurance companies and
governments are not sympathetic. The current options for infertile couples are painful,
expensive, and heart-breaking. Cloning has the potential to change the world for infertile
couples almost overnight.
A Child's right to be better than its parents - It's been suggested that parents have a duty to
see that their children have better lives than they do. This may mean making our children live
longer, helping them to be resistant to cancer, heart disease, any familial diseases, and all the
other problems that can be cured using what we learn from human cloning technology.
To take a step towards immortality - Human cloning essentially means taking a human being's
DNA and reversing its age back to zero. Dr. Richard Seed, one of cloning's leading proponents,
hopes that cloning will help us understand how to reverse DNA back to age 20 or whatever age
we want to be. Cloning would be a step towards a fountain of youth.
To make a future couple financially secure - With human cloning you could give a couple in
the future both a child from your DNA and the financial assets from your lifetime to start out
financially secure instead of struggling as most couples do now.
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Students’ version
To be a better parent - Human cloning can improve the parent-child relationship. Raising a
clone would be like having a child with an instruction manual. You would have a head start on
the needs and talents of your child. We are not saying that a clone would be a carbon copy with
no individuality. Our talents and desires are genetic, developmental, and environmental. We
would have a head start on understanding the genetic component of a cloned child.
Endangered species could be saved - Through the research leading up to human cloning we
will perfect the technology to clone animals, and thus we could forever preserve endangered
species, including human beings.
Animals and plants could be cloned for medical purposes - Through the research leading up
to human cloning, we should discover how to clone animals and plants to produce life-saving
medications.
Economics - Countries that fail to research human cloning will suffer economically. The
industrial revolution and Internet revolutions enriched the United States of America.
Biotechnology will lead the next economic revolution. Those countries that jump in first will
reap the rewards. Those who fail to begin research right away will fall behind. As an example:
Japan failed to jump on the Internet bandwagon and is now playing catch-up. Japan has banned
human cloning and will probably suffer by falling behind during the biotech revolution. One day
in the not too far distant future, Japan may realize its mistake.
Because the sick will demand it - Those resisting human cloning research will probably find
themselves shouted down by the sick and the maimed who desperately need such research.
Human cloning technology promises to cure many or all incurable diseases and the moral weight
of the dying and infirm will undoubtedly sway the politicians more than the arguments of the
healthy, who often remain ignorant of the potential of human cloning, because they have never
been motivated by suffering to look desperately for a cure.
Living on through a later-born twin - Some childless people feel that by being cloned by their
later-born twin would help them or their DNA to live on in the same sense that people who have
children live on.
<Reference article 2>
HUMAN CLONING: PROBLEMS FACED TODAY
(Extract)
http://www.msu.edu/~daughe29/atl/finalpaper.html
Since the first successful cloning of a mammal, a sheep named Dolly, was announced to the
public in 1997 a worldwide debate has been occurring about whether cloning humans is ethical.
Scientists have had the ability to clone organisms for decades now. The first cloning experiments
are dated back to the 1970s when scientists used amphibians. It wasn’t until the public found out
about Dolly that the debate on cloning started to heat up. With the ability to clone mammals, the
possibility to clone humans now seems closer than ever. Congress, the scientific community, and
the people around the world now are in a heated debate over the benefits and consequences of
cloning, especially with all of the uncertainties that scientists still have today about cloning
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Students’ version
humans. The current lack of knowledge of mammalian cloning techniques presents too many
risks to be used on humans.
The first ethical debate about the cloning of humans is genetic diversity. Genetic diversity
would be held to a screeching halt if humans were cloned instead of produced naturally. This
could be disastrous for humans if a certain strain of disease was present in the DNA sequence of
the clones. Then all of the clones would be susceptible to the same disease and it could in theory
wipe out the clones that were created from the DNA sequence. Humans would not be able to
adapt or evolve to certain situations. It would not be ethical to produce humans that would be
plagued by a certain disease for life. Nor would it be beneficial to the human race.
Another debate on cloning is focused on the therapeutic cloning procedures. This debate
centers on the benefits of therapeutic cloning and the loss of having to destroy human embryos
to obtain success. Therapeutic cloning is a procedure of cloning that provides many treatments
for humans. Instead of cloning a whole human body, therapeutic cloning procedures only clone
one specific part that needs “repair,” for example, making new organs for transplant. In order to
produce new organs though, scientists use cells that are called stem cells. These stem cells are
cells that have the ability to differentiate, or form, new types of cell tissue. Scientists are
currently working on new ways to obtain these stem cells. As of now, scientists are getting these
cells by taking them from human embryos. In order to this though, the embryos have to be
destroyed. This has brought up a huge debate on whether the embryos are human and deserve
basic human rights. If so, then this procedure would be murder. (Commentary on Human
Cloning, Byrne, J.A.) Abortion rights in many countries have already stated that the choices of a
grown adult override of those of the unborn embryo, while other pro-life advocates would argue
otherwise. Some people as well as myself believe that a human embryo should have all the basic
rights as a full grown human. Not granting the embryo a fair chance at life would be against the
future human’s basic rights.
Yet another ethical debate about cloning that has arisen is the abnormalities that take place
during and after cloning procedures. Approximately one-third of the mammals that have been
cloned have been born with or developed abnormalities. The most common abnormality that
these clones are born oversized. If these procedures where to be applied to use in human cloning
one-third of all humans that are cloned would suffer from these abnormalities. Many of the
cloned animals also develop respiratory, circulatory, and many other developmental problems.
The clones that do develop these abnormalities sometimes die because of the organ deficiencies
that develop. Killian, a scientist who studies cloning, formed a hypothesis that predicts that the
abnormalities in humans that would develop would be less than 30%. This number is
significantly high.
Since the scientists who study cloning already know that some abnormalities can and most
definitely will take place should not risk human lives just to further their knowledge on cloning.
The abnormalities that happen in natural human sexual reproduction is 3%. The deformities
involved with the cloning procedure are much higher. The abnormalities that develop from
natural sexual reproduction are not voluntarily planned.
The most important argument against cloning humans is the present inefficiency of it.
Many clones do not survive. Only a mere .1-5% of attempts at nuclear transfer from mammalian
cells result in live births. Out of that little percentage of clones that are born, about 50% of
newborns survive. All of the data means that 95-99.9% of all cloned mammals die. And of the
ones that survive, there is no guarantee that no abnormalities will be present. There is a certain
few failures when human sexual reproduction takes place also. These failures cannot be planned
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Students’ version
or predicted though. The failures of the cloning procedure have been proved.
As of right now, scientists are not nearly close enough to successfully cloning mammals.
Sure it has been done but not without a great deal of complications. Cloning humans now would
be deliberately producing humans that may not be normal, and may not even survive. I believe
that cloning humans should not be permitted because it is not ethical to produce humans just to
study science a little closer. Too many human lives would be wasted in order to someday have
the ability to clone humans successfully. Scientists should not be able to clone humans until
further research is done to prove it is completely safe. Still too many uncertainties exist about
human cloning, and it should not be permitted.
Topic of debate:
‘Human cloning consists of some many problems violating human ethics, so it should be
completely prohibited.’
Activity Guideline:
Refer to the reference articles 1 and 2 and state the points supporting or opposing the notion
about human cloning researches. Students should treat the authors’ personal ideas as references
only. However, you should focus on the evidences stated by the authors in establishing their
ideas. Hence, what are the information and evidences the authors have used to support their
viewpoints?
When students prepare the debating script, you should notice the reliability of the ideas and try to
quote some reliable evidences such as the results of scientific researches to support yourselves. It
can prevent you from just expressing personal subjective ideas in the debate.
Issue 2. Embryonic stem cells research
Please read the article below as debating information
<Reference article 1>
The Stem Cell Challenge
What hurdles stand between the promise of human stem cell
therapies and real treatments in the clinic? (Extract)
http://www.sciam.com/print_version.cfm?articleID=000DFA43-04B1-10AA-84B183414B7F00
00
Robert Lanza and Nadia Rosenthal
Stem cells raise the prospect of regenerating failing body parts and curing diseases that have so
far defied drug-based treatment. Patients are buoyed by reports of the cells' near-miraculous
properties, but many of the most publicized scientific studies have subsequently been refuted,
and other data have been distorted in debates over the propriety of deriving some of these cells
from human embryos.
Provocative and conflicting claims have left the public (and most scientists) confused as to
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Students’ version
whether stem cell treatments are even medically feasible. If legal and funding restrictions in the
U.S. and other countries were lifted immediately, could doctors start treating patients with stem
cells the next day? Probably not. Many technical obstacles must be overcome and unanswered
questions resolved before stem cells can safely fulfill their promise.
For instance, just identifying a true stem cell can be tricky. For scientists to be able to share
results and gauge the success of techniques for controlling stem cell behavior, we must first
know that the cells we are studying actually possess the ability to serve as the source, or "stem,"
of a variety of cell types while themselves remaining in a generic state of potential. But for all
the intensive scrutiny of stem cells, they cannot be distinguished by appearance. They are
defined by their behavior.
Most versatile are embryonic stem (ES) cells, first isolated in mice more than 20 years ago. ES
cells come from the portion of a very early-stage embryo that would normally go on to form
three distinctive germ layers within a later embryo and ultimately all the different tissues of the
body. ES cells retain this potential ability to produce any cell type in the body, making them
pluripotent.
Most of the existing human ES cell lines in the world were derived from unused embryos created
for couples seeking in vitro fertilization (IVF). Researchers working with these cells have found
that they usually recover after freezing and thawing and can differentiate into assorted cell types
in a culture dish. But it is becoming clear that not all human ES cell lines are the same.
Seeking Stemness
Some lines will differentiate into only certain cell types; others grow sluggishly in culture. To
ensure that these cells are pluripotent before using them in research, two possible tests, already
common in nonhuman ES cell studies, have been proposed by a group of American and
Canadian biologists hoping to set standards for experimentation with human ES cells. One
would involve injecting the ES cells into an animal's body tissue. If they form a teratoma--a
distinctive tumor containing cell types from all three embryonic layers--their pluripotency is
proved. Another way to test putative ES cells is to mark them, then inject them into a developing
animal embryo. When the animal is born, if the marked cells turn up in all its tissues, the cell
line is deemed pluripotent. But testing human embryonic stem cells in this manner would create
a chimeric animal with human DNA throughout its body, a prospect many find ethically
troubling. What is more, passing the latter test does not always guarantee that the cells will
differentiate in the lab.
The need to find more reliable markers that distinguish truly pluripotent ES cells is driving
widespread attempts to catalogue the genes that are turned on or off at various times in cultured
ES cells. Having such a gene expression profile would not only provide a way of identifying
pluripotent ES cells, it would also offer tremendous insight into the properties that confer their
"stemness." Unfortunately, to date, gene expression profiles of ES cells have yielded conflicting
results, and the search for a clear ES cell signature continues.
Of course, the goal of stem cell research is to replace or regenerate failing body parts, such as
pancreatic insulin-producing cells in diabetics or dopamine-producing neurons in people with
Parkinson's disease. But techniques for coaxing ES cells to differentiate into desired cell types
are far from perfected.
Putting cells to work
It would be ideal if we could simply inject ES cells into the part of the body we wish to
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Students’ version
regenerate and let them take their cues from the surrounding environment. ES cells'
pluripotency, however, makes this far too dangerous an approach for human therapy. The cells
might form a teratoma or could differentiate into an undesirable tissue type, or both. In animal
experiments, teratomas containing fully formed teeth have been reported.
Rather than risk creating a tumor or a tooth in a patient's brain or heart with direct ES cell
injections or struggling to produce specific functional tissues, many ES cell researchers are now
striving for a middle ground. By coaxing ES cells into a more stable, yet still flexible,
progenitor-cell stage before administering them, we can avoid uncontrolled differentiation while
still taking advantage of environmental cues to generate the desired cell types.
Even though these progenitor cells can take to their environment and initiate the generation of
new tissue, they would still be subject to attack by the patient's own body. ES cells and their
derivatives carry the same likelihood of immune rejection as a transplanted organ because, like
all cells, they carry the surface proteins, or antigens, by which the immune system recognizes
invaders. Hundreds of combinations of different types of antigens are possible, meaning that
hundreds of thousands of ES cell lines might be needed to establish a bank of cells with immune
matches for most potential patients. Creating that many lines could require millions of discarded
embryos from IVF clinics.
Topic of debate:
‘Embryonic stem cell therapy has completely neglected human ethics’
Activity Guideline:
The reference article has raised the discussion on the imperfections of embryonic stem cell
therapy, included technical incompleteness and some technical problems such as abnormal
embryo. Lots of animals are used as subjects during biotechnology exploration. The vigorous
controversy in embryonic stem cell therapy is owing to its relatedness to human embryo. What are
your opinions on the issue about whether embryo should be regarded as a life?
When students prepare the debate script, you should notice the reliability of the ideas and try to
quote some reliable evidences such as the results of scientific researches to support yourselves. It
can prevent you from just expressing personal subjective ideas in the debate.
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Students’ version
Activity 4: Group Debating
Worksheet
Please answer the question individually (not more than 100 words) after the debate:
Imagine you are a patient waiting for kidney transplant and you are waiting for suitable organ
donation for transplantation. Now a new research has been launched to use embryonic stem cells
to cultivate kidney cells, are you willing to take part in it? If this research would use up more than
millions of human embryos, what is your opinion?
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Students’ version
Extended Activity：
Students can have further investigations and discussions on the topics below：
Additional issue for debating: Gene therapy
Topic of debate:
Patients receiving ‘gene therapy’ has to take the risk that is still unknown and uncontrolled
medically. From patient’s point of view and their vital interest, receiving ‘gene therapy’ does
more harm than good.
Reference articles:
1. <Cancer risk clouds gene cures>
Author: Bob Holmes 2003.03.15
http://www.eurekalert.org/pub_releases/2003-03/ns-crc031203.php
2.〈論基因治療之科技風險與醫療傷害之救濟〉
撰文／牛惠之 助理教授 2003.01.15
國立清華大學科技法律研究所
http://www.bio.idv.tw/data/data2/2003011501.htm
Issue for information collection：Ethical problems about DNA database
Reference articles:
1. Original title: <The FBI’s national DNA database>
Source:
Nature Biotechnology 16 (1998), 987
Author:
Russ Hoyle
2. <Genetic Discrimination in Health Insurance>
http://www.genome.gov/page.cfm?pageID=10002328
3.〈冰島的浮士德契約？全國基因資料庫的建立與省思〉
撰文／何建志【生物科技與法律研究通訊】 – 第一期 – 1999 年 1 月 11 日
4. 〈美國參議院通過禁止基因歧視的法案〉
李裕勳整理，資料來源：
http://www.nlm.nih.gov/medlineplus/news/fullstory23075.html
http://www.medicalnewstoday.commedicalnews.php?newsid=20207
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Students’ version
Extended readings:
Students can refer to the newspaper articles below to further discuss the ethical issues of science:
Science turns monkeys into drones -- Humans are next,
genetic experts say
http://www.infowars.com/print/bravenewworld/monkey_drones.htm
London Times October 17, 2004
The Times, London
LONDON - Scientists have discovered a way of manipulating a gene that turns animals into
drones that do not become bored with repetitive tasks. The experiments, conducted on monkeys,
are the first to demonstrate that animal behaviour can be permanently changed, turning the
subjects from aggressive to "compliant" creatures.
The genes are identical in humans and although the discovery could help to treat depression and
other types of mental illness, it will raise images of the Epsilon caste from Aldous Huxley's
futuristic novel Brave New World.
The experiments -- detailed in the journal Nature Neuroscience this month -- involved blocking
the effect of a gene called D2 in a particular part of the brain. This cut off the link between the
rhesus monkeys' motivation and reward.
Instead of speeding up with the approach of a deadline or the prospect of a "treat," the monkeys
in the experiment could be made to work just as enthusiastically for long periods. The scientists
say the identical technique would apply to humans.
"Most people are motivated to work hard and well only by the expectation of reward, whether it's
a paycheque or a word of praise," said Barry Richmond, a government neurobiologist at the U.S.
National Institute of Mental Health, who led the project. "We found we could remove that link
and create a situation where repetitive, hard work would continue without any reward."
The experiments involved getting rhesus monkeys to operate levers in response to colour changes
on screens in front of them. Normally they work hardest and fastest with the fewest mistakes if
they think a reward for the "work" is imminent.
However, Mr. Richmond's team found that they could make the monkeys work their hardest and
fastest all the time, without any complaint or sign of slacking, just by manipulating D2 so that
they forgot about the expectation of reward.
The original purpose of the research was to find ways of treating mental illness, but the
technicalities of permanently altering human behaviour by gene manipulation are currently too
complex, he said.
However, he and other scientists acknowledge that methods of manipulating human physical and
psychological traits are just around the corner, and the technology will emerge first as a lucrative
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add-on available from in vitro fertilization clinics.
"There's no doubt we will be able to influence behaviour," said Julian Savulescu, a professor of
ethics at Oxford University.
"Genetically manipulating people to become slaves is not in their interests, but there are other
changes that might be. We have to make choices about what makes a good life for an individual."
In a presentation at a Royal Society meeting titled Designing Babies: What the Future Holds,
Yuri Verlinsky, a scientist from the University of Chicago who is at the forefront of embryo
manipulation, said: "As infertility customers are investing so much time, money and effort into
having a baby, shouldn't they have a healthy one and what is to stop them picking a baby for its
physical and psychological traits?"
Gregory Stock, author of Redesigning Humans and an ethics specialist from the University of
California, agrees.
"I don't think these kind of interventions are exactly round the corner, they are a few years away,
but I don't think they are going to be stopped by legislation," he said.
Sperm And Eggs Grown From Stem Cells
http://www.rense.com/general66/spermandeggs.htm
Maxine Frith
Social Affairs Correspondent
The Independent - UK
20/6/2005
The shortage of donated eggs and sperm for fertility treatment could be solved after British
scientists found they can both be grown from laboratory stem cells.
But some specialists warned the discovery raised serious ethical questions, saying it could mean
that a single man could provide both the sperm and egg for fertility treatment, making him
genetically father and mother of his child.
They also claimed the technique came close to human cloning, although scientists who conducted
the study denied that.
Researchers from the Centre for Stem Cell Biology at the University of Sheffield studied six
human embryonic stem cell (HESCs) lines taken from very early embryos that had been donated
by couples undergoing IVF treatment.
HESCs are the building blocks of human development and turn into any type of cell, such as
organs or tissue. But scientists have not been clear about when HESCs begin to differentiate into
primordial germ cells (PGCs), which are the ancestral cells that eventually form sperm and eggs.
The Sheffield researchers allowed the human stem cells to develop into collections of cells called
embryoid bodies, and then tested them to see which genes were active in them.
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Within two weeks of development, a very small proportion of cells in the embryoid bodies had
begun to "express" some of the genes found in PGCs.
Some also began to express proteins that are only found in maturing sperm, suggesting that
human stem cells can develop into PGCs, and eventually eggs and sperm.
Dr Behrouz Aflatoonian, who led the research, said: "Ultimately, it might be possible to produce
sperm and eggs for use in assisted conception treatments. This is a long way off, and we would
have to prove that it was safe because, for example, the culture process may cause genetic
changes.
"For some men and women, this would be the only route for producing sperm and eggs. It would
not be reproductive cloning as fertilisation would involve only one set of gametes produced in
this way, and a unique embryo would form."
One in seven couples in Britain experiences fertility problems, and about 7,000 a year are treated
using donated eggs or sperm. Some couples are able to use their own eggs or sperm, but others
with particular problems are reliant on donated samples.
Only 250 men and 1,100 women donate their sperm or eggs each year, meaning there is a drastic
shortage.
There are also concerns that fewer people may be prepared to become donors after the rules
governing anonymity changed, making it possible for children born as a result of fertility
treatment to obtain details about their biological parents.
©2005 Independent News & Media (UK) Ltd.
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Human Skin Cells Turned Into Stem Cells
http://www.isscr.org/public/conversion.htm
Jason West, Shannon McKinney-Freeman, Ph.D., Susan Garfinkel, Ph.D., and Suzanne Kadereit,
Ph.D.
In the August 2005, issue of the journal Science, Kevin Eggan and colleagues at Harvard
University fused human skin cells and human embryonic stem cells. The resulting hybrid cells
retained properties of the embryonic stem cells, suggesting that specialized adult cells can
convert into a less specialized state.
Prior to this study, the ability to coax a more specialized adult cell (or the DNA of an adult cell)
into a less specialized state had been demonstrated via the process of somatic cell nuclear
transfer. In that process, an adult cell is fused with an egg, whose own genetic material is
removed, so the egg contains the genetic material from the adult cell. The egg is then coaxed to
develop like a fertilized egg, and at the blastocyst stage of development (about 4-5 days and
100-200 cells), embryonic stem cells can be isolated that are a genetic match to the adult cell
donor. This procedure has generated much controversy due to its use of unfertilized human eggs
(which must be donated) and the creation, and subsequent destruction, of human embryos to
enable the isolation of embryonic stem cells.
The current study directly fused adult skin cells with existing human embryonic stem cells, so no
human eggs were involved. Although the fused cells still contained the genetic material, or DNA,
from both of the two cells used (adult skin cells and embryonic stem cells), they behaved very
much like embryonic stem cells. The fused cells could generate many different cell types of the
body, including brain cells, hair cells, skeletal muscle and intestine and also expressed many
genes that are characteristic of embryonic stem cells.
It remains to be determined if the fused cells, which contain twice the amount of DNA as a
normal cell, will form functional cells that will be useful for treatments. Even embryonic stem
cells derived in the classical way (from human eggs at the blastocyst stage) have yet to be used
successfully to treat human disease. Thus, many challenges still remain in simply characterizing
these exciting new cells and understanding the extent to which they mirror embryonic stem cells.
Clinical uses are undoubtedly years down the line, if at all.
However, despite these limitations, this research offers an exciting hope that someday any adult
cell could be converted into an embryonic stem cell. Normally, a cell is guided through
development from a less specialized state to more specialized state by a specific program.
Although cells share common DNA, specific factors within cells influence the DNA, allowing
one cell type to be distinguished from another. For example, a nerve cell and a heart cell within a
person have the same DNA, but other factors program the nerve cell to be a nerve cell and the
heart cell to be a heart cell. Thus, changing these factors will change, or reprogram, one cell into
behaving like a different cell.
This research showed that factors present within the embryonic stem cells, instead of human
eggs, caused adult cells to reprogram. Future studies aimed at identifying what factors are
responsible will likely grow out of this research. In addition, the reprogramming of adult cells by
embryonic stem cells, in lieu of human eggs, has overcome the hurdle of getting enough raw
materials to study the factors causing reprogramming, since human eggs are a scarce commodity
and embryonic stem cells are available in vast numbers. Nonetheless, the current procedure still
required the use of embryonic stem cells that were created from human embryos, and therefore
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still raises controversy among some groups opposed to research using embryonic stem cells.
In the future, knowledge of factors necessary for reprogramming could potentially allow for the
creation of “embryonic” stem cells arising directly from an adult cell without the use of any
preexisting embryonic stem cells or human eggs. It must be noted, however, that years of
research on other model systems such as the frog and mice have failed to identify such factors
that allow for successful reprogramming of an adult cell without the use of eggs or embryonic
cells. Thus, this procedure currently only allows for the generation of fused cells with twice the
genetic content of normal human cells and does not offer an alternative to using human
embryonic stem cells. Even so, it offers an exciting new tool to study reprogramming for stem
cell researchers.
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