IELTS Reading Passage 2 - Extracted Text
How the Petri Dish Supports Scientific Advances
A simple piece of scientific equipment is
helping research in three institutions in Cambridge, UK.
Section A
A Petri dish, invented by German
microbiologist Julius Richard Petri in 1887, rarely receive the appreciation or
attention that their more complex lab companions like the microscope enjoy.
They are simple, utilitarian little things, and it’s understandable that some
people see them as just shallow dishes with lids. But Petri dishes deserve
celebrating: they are still at the forefront of scientific discovery.
Section B
The invention of the Petri dish, and the
advances it has helped to create, are part of a bigger whole, of course—the
development of glass scientific instruments, from microscope lenses to
laboratory beakers. In The Glass Bathyscaphe: How Glass Changed the World, Alan
Macfarlane argues that without glass, the Renaissance and the scientific
revolution would never have happened.
Around 70 percent of what we know about the world comes in through our eyes,
Macfarlane points out, and glass instruments enabled us to see better. Until
about 1400, knowledge was based on what people had been told in the past.
‘Glass allowed the growth of the experimental method. Don’t trust what you are
being told: see it for yourself. It was transformational,’ he says.
Section C
At the Wellcome-MRC Cambridge Stem Cell
Institute, Professor Ludovic Vallier says that his first encounter with a Petri
dish was a classic example of understanding the world in this way: students
used the dishes to see which bacteria could grow in the presence of
antibiotics. “It’s good to see things grow,” he says. “It was a fascinating
experience. Now, we grow cells in the Petri dish, and we don’t use glass
anymore, but plastic.”
Today, his team focuses on stem cells, which have the capacity to become any
cell type in the human body: neurons, skin cells, liver cells, and so on.
Vallier and his colleagues study them in order to understand how they do this,
and how they can produce more cells. And to study them, they need to grow them.
“We put the stem cells in the dish and feed them to keep them dividing,” he
says. “And when we grow them, we can distribute them in new Petri dishes, and
feed them again. We can also teach them to want to produce new cells. So by
feeding them this medium we can allow the cells to become neurons, cardiac
cells, liver cells, and so on. We can then model disease in a lab.”
Section D
‘Disease in a dish’ is also the focus of Dr.
Meritxell Huch’s team at the Gurdon Institute. They use between 50 and 150
Petri dishes every day to grow mouse and liver human liver cells in order to
study how the liver can regenerate itself.
Huch’s team is examining the molecular mechanisms by which these cells decide
to multiply. She says: “You can divide regeneration into different phases. The
cells first have to realize that there is damage and activate the response.
Once they activate the response, the cells will proliferate to compensate for the
loss of cells owing to the damage. And once they have proliferated, they have
to become functional cells.”
Section E
In the MRC Laboratory of Molecular Biology,
Dr. Madeline Lancaster and her team grow ‘mini-brains’ in hundreds of Petri
dishes. Here, the dish has been specially treated to stop cells from sticking
to it and to encourage them to float freely.
Dr. Lancaster explains that they want the cells to develop in three, rather
than two, dimensions as that’s the way our brains are. “If you can grow neurons
on a dish in two dimensions, you can see individual neurons and see what they
do, but you won’t be able to understand the architecture of those cells—their
positioning relative to one another.” She says that this new method gives you a
structure that looks a lot more like that of an actual developing brain.
Section F
The aim of this research is to look at
exactly how neurons are made and how that differs in humans compared with other
species. One day, says Lancaster, this work could translate into understanding
far more about Alzheimer’s disease, Parkinson’s, and schizophrenia. So, in a
world of cutting-edge and highly complex technology, Petri dishes, in their
relative simplicity, remain a vital weapon in the fight against the world’s
most difficult diseases. And they also enable a hands-on approach that she
finds extremely satisfying.
“It is a bit like gardening,” she says. “You’re taking care of this thing. You
keep an eye on it and you check it every day. You change the media this or that
day to help it grow better. It’s rewarding to see something grow before your
eyes. There’s something about the interplay between new, next-generation, and
classic technologies. They give you capabilities that were just not possible
before.”
Questions 14–18
Which section contains the following
information?
Write the correct letter, A–F, in boxes 17–22 on your answer sheet.
14. A description of an experiment involving both human and non-human cells of
a specific type.
15. Possibilities for improved research into various serious medical
conditions.
16. Contrasting views of the importance of the Petri dish.
17. A change remarked on by one scientist in the material used for the Petri
dish.
18. A claim that the Petri dish enables a scientist to monitor the progress of
an experiment on a regular basis.
Questions 19–23
Look at the following statements (Questions
23–28) and the list of people below. Match each statement with the correct
person, A, B, C, or D.
Write the correct letter, A, B, C, or D, in boxes 23–28 on your answer sheet.
19. To deal with injury, cells must go through a series of activities in a
particular order.
20. One technological development formed the basis of all modern scientific
research.
21. A modification to the Petri dish allows experiments to provide more
accurate information.
22. Petri dishes allow observation of medical conditions that are normally
impossible to observe.
23. Visual evidence is a very important requirement for the provision of
reliable information.
List of People
A. Alan Macfarlane
B. Professor Ludovic Vallier
C. Dr. Meritxell Huch
D. Dr. Madeline Lancaster
Questions 24–26
Complete the summary below.
Choose ONE WORD ONLY from the passage for each answer.
Write your answers in boxes 29–32 on your answer sheet.
Research in the MRC Lab of Molecular Biology
A team led by Dr. Madeline Lancaster is using special Petri dishes which
prevent brain cells from 24 ________ to them. The aim is to allow the neurons
to grow in three 25 ________. This results in a 26 ________ that resembles a
developing brain. The technology could help scientists study how neuron
production varies in different 27 ________, leading to possibilities for
increased medical knowledge.
Questions 14–18
Which section contains the following information?
14. A description of an experiment involving both human and non-human cells of a specific type.
👉 D (Dr. Huch – grows mouse and human liver cells).
15. Possibilities for improved research into various serious medical conditions.
👉 F (Lancaster mentions Alzheimer’s, Parkinson’s, schizophrenia).
16. Contrasting views of the importance of the Petri dish.
👉 B (Macfarlane stresses importance of glass; some dismiss Petri dish as trivial).
17. A change remarked on by one scientist in the material used for the Petri dish.
👉 C (Vallier – “we don’t use glass anymore, but plastic”).
18. A claim that the Petri dish enables a scientist to monitor the progress of an experiment on a regular basis.
👉 F (Lancaster – compares it to gardening, checking it daily).
Questions 19–23
Match each statement with the correct person.
19. To deal with injury, cells must go through a series of activities in a particular order.
👉 C (Dr. Huch – regeneration phases).
20. One technological development formed the basis of all modern scientific research.
👉 A (Alan Macfarlane – glass).
21. A modification to the Petri dish allows experiments to provide more accurate information.
👉 D (Dr. Lancaster – special dish prevents cells sticking, allows 3D growth).
22. Petri dishes allow observation of medical conditions that are normally impossible to observe.
👉 B (Professor Vallier – stem cells grown to model disease).
23. Visual evidence is a very important requirement for the provision of reliable information.
👉 A (Macfarlane – seeing through glass).
Questions 24–26
Complete the summary (ONE WORD ONLY).
24. sticking
25. dimensions
26. structure
27. species
✅ Final Answers List
14. D
15. F
16. B
17. C
18. F
19. C
20. A
21. D
22. B
23. A
24. sticking
25. dimensions
26. structure
27. species
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