READING: THE HUMAN GENOME
A) Match the question on the left with the correct answer on the right.
1. What is the human Genome Research A. The first is the process of determining
the positions of genes on a chromosome
Project?
and the distance between them. The second
identifies the order in which the basic
chemical units of DNA appear. It is the
order that the chemical units appear in the
DNA that is the basis of all diversity, and
determines not only eye colour and hair
texture, but whether an organism is a
human, a fruit fly or an elephant.
B. Interest in the mapping and sequencing
2. What is a genome?
of the human genome began gaining
momentum with scientists in the 1980s. In
1990, the U.S. Congress approved a 15year research plan presented by the
Department of Energy and the National
Institutes of Health that was to be coordinated with research taking place in
other countries.
C. Computers were used to break the DNA
3. What is meant by "mapping and
into sections the length of 35,000 "letters" sequencing" the human genome?
- or chemicals -- and to determine how
they were arranged on the chromosomes.
Then work was begun on the more difficult
task of determining the precise sequence of
the 3.2 billion pairs.
4. What are the potential benefits of this D. Its aim is to discover and map all of the
80,000 to 100,000 human genes and to
research?
determine the exact sequence of the 3.2
billion basic units of human DNA. Primary
funding for the research comes from the
U.S. National Institutes of Health and
Wellcome Trust, a philanthropic
organisation in London. Other countries
participating in the project include
Australia, Brazil, Canada, etc.
E. No. Scientists also have worked on the
5. What exactly is DNA?
genome of less complicated organisms
such as
yeast and the fruit fly. Knowing how the
genomes of simpler organisms work is
expected to contribute to the understanding
of more complex organisms, such as
humans. In its research on humans, the
Human Genome Research Project uses
DNA taken from volunteers whose
6. How did the research idea get
started?
7. Has the research focused only on
humans?
8. What role has technology played in
the research?
9. Why were there two competing
groups working on the human genome?
identities will be withheld to ensure their
privacy.
F. That is what interested bystanders
would like to know. Both sequences are to
be published in scientific journals later this
year, however, and both are expected to be
available on the Internet. Celera's will be
on celera.com. The government's will be
on the Human Genome Project's site
http://www.ornl.gov/hgmis/project/progres
s.html.
G. In 1998, a private company, Celera
Genomics Inc., negotiated with the
government-subsidised Human Genome
Research Project to bring in new
technology
that would speed up the research.
Central to Celera's effort was the use of
lasers and other new technologies that
enabled
researchers to detect sequences several
thousand letters long -- letter by letter. J.
Craig Venter of Celera says the company's
researchers are able to sequence between
100,000 and 200,000 samples a day, and
that each produces about 600 letters of
genetic code.
Ultimately the government project and
Celera were unable to agree on a working
relationship and went their separate ways.
In June 2000, however, both parties and a
third participant, the Sanger Centre in
London, co-ordinated their announcement
that they had successfully sequenced the
human genome.
H. Although DNA dictates everything a
cell does, the purpose of most DNA is not
yet known. What is known is that changes
in the DNA can lead to illness, to disease
and to more subtle things, such as how the
body responds to various substances.
Decoding DNA is expected to lead to
enormous improvements not just in the
diagnosis and treatment of disease and
illness, but also in new sources of energy,
healthier crops and livestock -- even
improvements in criminal investigation
and detection.
I. It consists of long chains of chemical
compounds with repeating structural units
10. Are the findings identical?
called base pairs or nucleotides. In a DNA
molecule, two strands of nucleotides wrap
around each other and look like a twisting
ladder known as the double helix.
The long sides of the ladder are made of
sugar and phosphate molecules. The rungs
are composed of the chemicals adenine
(A), thymine (T), cytosine (C) and guanine
(G),
which combine to form the base pairs. The
way the 3.2 billion base pairs are arranged
is called the DNA sequence.
Unravelled and tied together, the strands of
DNA in humans would be more than 5 feet
long, but only 50-trillionths of an inch
wide.
J. It is all the DNA in an organism,
including the genes that carry the
information necessary for the synthesis of
proteins required by all organisms. These
proteins dictate the characteristics and
functions of the organism, and sometimes
even its behaviour. In most cases this
genetic material, which includes 23 pairs
of chromosomes in the human body and
80,000 to 100,000 genes, are found in each
of the approximately 100 trillion cells in
the human body.
Your Answers:
1. _____ 2. _____ 3. _____ 4. _____ 5. _____
6. _____ 7. _____ 8. _____ 9. _____ 10. _____
B) Vocabulary Exercise. Find a word in the text that means:
1) Providing money for an activity, organisation, etc.
2) A way of acting in a particular manner.
3) A plant or plant product such as grain, fruit or vegetables
grown by a farmer.
4) Animals kept on a farm such as cattle or sheep.
5) Made clear.
6) Refused to give.
7) Cause to move or go faster.
8) Gave the power or means to do something.
9) Lacking the means or opportunity to do something.
10) A serious magazine, usually produced by a specialist society.
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