Locating and Matching Information
Just
like matching headings, matching information questions are not in the same order as the passage.Study Tip Some examples of the type of information you may be asked to find
are:
• a number • a cause • a finding
• a date • an effect • an account
• a measurement • a conclusion • a reaction
• a reason • the problems • a description.
When you are reading different passages in this book, think about whether the
information matches any of these types.Spend two minutes skim reading the passage
below, so that you are familiar with the type of information it contains.How geckos cope with wet feet
A Geckos are remarkable little lizards,
clinging to almost any dry surface, and Alyssa Stark, from the University of
Akron, US, explains that they appear to be equally happy scampering through tropical
rainforest canopies as they are in urban settings.
'A lot of gecko studies look at the very small adhesive structures on their toes to
understand how the system works at the most basic level: says Stark. She adds
that the animals grip surfaces
with microscopic hairs on the soles of their feet, which
make close enough contact to be attracted to the
surface by the minute forces between atoms.
B However, she and her colleagues Timothy
Sullivan and Peter Niewiarowski were
curious about how the lizards
cope on surfaces in their natural habitat. Explaining
that previous studies had focused on the reptiles
clinging to artificial dry surfaces, Stark says 'We
know they are in tropical environments that
probably have a lot of rain and geckos don't suddenly
fall out of the trees when it's wet Yet, the animals do
seem to have trouble getting a grip on smooth, wet,
artificial surfaces, sliding down wet vertical
glass after several steps. The team decided to find out
how geckos with wet feet cope on both wet and dry
surfaces.
C First, they had to find out how well their
geckos clung onto glass with dry feet.
Fitting a tiny harness around the
lizard's pelvis and gently lowering the animal
onto a plate of
smooth glass, Stark and
Sullivan allowed the animal to become
well attached before connecting the
harness to a tiny motor and
gently pulling the lizard until it came unstuck.
The geckos hung on tenaciously, and only came
unstuck at forces of around 20N - about 20 times their own body weight.'In my view,
the gecko attachment system is
over-designed:says Stark.
D Next, the trio sprayed the glass plate with
a mist of water and
re-tested the lizards, but this time the animals had
problems holding tight. The droplets were
interfering with the lizards' attachment mechanism,
but it wasn't clear how. And when the team
immersed the geckos in a bath of room-temperature water with a smooth glass bottom, the animals were completely unable to anchor themselves to the smooth surface. 'The toes are super-hydrophobic,' (i.e. water repellent) explains Stark, who could see a silvery bubble of air around their toes. But, they were unable to displace the water around their feet to make the tight contact that usually keeps the
geckos in place.
E Then the team
tested the lizard's adhesive forces on the dry surface when their feet had been soaking for 90 minutes, and found that the lizards could barely hold on, detaching when they were
pulled with a force roughly equalling their own
weight. 'That might be the sliding behaviour that we see when the geckos climb vertically up misted glass: says Stark. So, geckos climbing on wet surfaces with damp feet are constantly on the verge of slipping and Stark adds that when the soggy lizards were faced with the misted and
immersed horizontal surfaces, they slipped as soon as the rig
started pulling. Therefore geckos can walk on wet surfaces, as long as their feet are reasonably dry. However, as soon as their feet get wet, they are
barely able to hang on,
and the team is keen to understand how long it takes geckos to recover from a
drenching.What is the main purpose of the passage?