Download Activity Booklet – Task 1

Acknowledgments
The investigative tasks included in this Science Olympiad booklet are the result of a team
effort and reflect the contributions of Ms Miriam Muscat, Mr Joseph Cutajar and
Mr Michael Mercieca.
Extended thanks to Mr Joe Bartolo (Senior Technical Officer) and his team of technicians
for the excellent lab/equipment organisation and preparation.
Much appreciation to Mr Robert Borg (Head of School) for hosting the event at St Theresa
College Secondary School.
Special thanks are due to Mr Joseph Cutajar for his technical support, design and
compilation of the final booklet version.
Table of Contents
Acknowledgments....................................................................................................................................... 2
Instructions .................................................................................................................................................... 2
Overview .......................................................................................................................................................... 3
Why Light Matters .................................................................................................................................. 3
Task 1 ................................................................................................................................................................ 5
Space for Rough Work ............................................................................................................................ 13
Space for Rough Work ............................................................................................................................ 14
Space for Rough Work ............................................................................................................................ 15
Instructions
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SAFETY FIRST – wearing a lab coat together with safety specs is mandatory at all
times. The use of disposable gloves is also recommended. The lamp provided on
your workstation is connected to a 240 V mains supply and can become very hot
to touch. Proper caution is advised.
You are asked to attempt all questions and write your answers clearly in the
spaces provided. Any work scribbled on the ‘Rough Work’ space provided will not
be considered.
Each team is requested to clean the lab station adequately after handing in the
script to the lab supervisor.
It is important that all laboratory equipment is handled very carefully. In case of
any breakages report immediately to the lab supervisor.
You are also reminded of the necessity of good English and orderly presentation
of your answers.
Overview
Why Light Matters
From sunsets to rainbows, from the blues and greens of the ocean to the remarkable
range of colours of plants and animals, our first experiences of light and colour are
through what we see in the natural world.
Photosynthesis
Green plants, algae and some bacteria
are able to produce the organic
compounds
that
they
need.
Photosynthesis involves many chemical
reactions during which sunlight energy
is absorbed by chlorophyll pigments
and converted into chemical energy.
Photosynthesis is an essential process
on which all animals depend. Think of adding a teaspoon of sugar in your coffee, eating a
chicken burger or breathing oxygen in the air. All these actions depend directly or
indirectly on plant material!
Refraction
A rainbow is a beautiful natural phenomenon that occurs when drops of rainwater meet
sunlight. The multi-colour arch is produced by a fundamental process called refraction,
or the “bending” of light. In optics, refraction is a
phenomenon that often occurs when waves
travel from a medium with a given refractive
index to a medium with another at an oblique
angle. A lens is a carefully moulded piece of
transparent material that refracts light rays in
such a way as to form an image. Lenses serve to
refract light at each boundary. As a ray of light
enters a lens, it is refracted, and as the same ray
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of light exits the lens, it is refracted again. The net effect of the refraction of light at these
two boundaries is a change in the direction of the light ray.
Matter and Light
The relationship between matter and light may
not be obvious. However, matter and light are
inextricably related to each other.
Light is generated when enough energy is
produced during a chemical reaction. Indeed,
humans have used fires as a source of light.
Courtesy of: commons.wikimedia.org
The chemical reactions that produce light in
different colours form the basis of the fireworks industry. Fireworks are popular within
traditional local village feasts. However, they may be a source of pollution.
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Task 1
“…Photosynthesis involves many chemical reactions during
which sunlight energy is absorbed by chlorophyll pigments and
converted into chemical energy.”
1) The plant provided in the lab is Syngonium podophyllum, commonly known as African
Evergreen, Arrowhead Vine, Five Fingers and Goosefoot plant. This is a common,
ornamental, indoor plant but is considered a weed in rainforests. The leaves vary in
size, shape and colour depending on their position on the plant. Mature leaves are
dark green with silvery-white veins. This plant reproduces vegetatively in the wild
and is spread by cuttings in cultivation.
Figure 1
Biology students wanted to investigate the leaf’s surface area able to carry out
photosynthesis.
a) Write the species name of this plant.
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(1 mark)
b) Using the 1.0 cm grid overleaf, draw a scale diagram and calculate the surface area
of a leaf from the plant provided.
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(1 mark)
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c) Design an experiment to investigate whether the whole leaf’s surface area is able
to carry out photosynthesis. Your report should include:
i) a list of the steps for the procedure carried out and ONE reason for each step;
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(8 marks)
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ii) a labelled diagram of the set-up of your experiment;
(2 marks)
iii) TWO precautions taken during the investigation;
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(2 marks)
iv) a conclusion derived from your investigation and ONE reason for it.
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(1, 1 mark)
d) Syngonium podophyllum reproduces vegetatively or can be spread by cuttings.
Name this type of reproduction.
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(1 mark)
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2) Students constructed the apparatus shown below. A cork board was attached to a
bicycle wheel mounted in a way to rotate clockwise by a motor at 1 revolution per
minute. This slow rotation approximates a weightless environment for the seeds.
Study the apparatus and then answer the questions that follow.
motor
rotating bicycle
wheel
broad bean seed
pinned to damp
cotton wool and
cork based board
a) On the diagram above, draw the growing shoots and roots after 10 days. Label the
shoots and roots clearly.
(2 marks)
b) Name the hormone responsible for this growth.
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(1 mark)
c) Name the apparatus used in the lab that works using the same concept shown in
the diagram.
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(1 mark)
d) On the diagram below, draw the growth response of the shoot and root if the
bicycle wheel stops rotating. Label the shoot and root clearly.
(1, 1 mark)
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3) A biology teacher was interested in creating a bottle garden in the lab. She discussed
with the students which bottle to use among a clear, brown or green glass bottle of
equal thickness.
a) Explain the importance of comparing glass bottles of equal thickness.
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(1 mark)
b) The graph below shows the intensity of the light that is transmitted through the
three differently coloured glass bottles.
c) Name the glass bottle colour most suitable to use for the bottle garden. Give ONE
reason for your answer.
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(1, 1 mark)
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4) A tropical rain forest is a region of year-round warmth ranging from 20 − 34°C and
an average rainfall of 125-660 cm. The following pictures show the different layers of
a tropical rainforest and typical plants growing in this environment.
Emergent
layer
Canopy
layer
Under
canopy
layer
Forest
floor
a) Name the phylum to which the Crow’s Nest Fern belongs.
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(1 mark)
b) Leaves in the canopy layer are smooth, oval shaped and pointed. Give ONE reason
for this structure.
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(1 mark)
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c) Some trees in the emergent layer have straight, thin trunks. They are shallow
rooted and develop buttress roots. State how these types of roots can be helpful
to the plant.
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(2 marks)
d) Trees in the canopy layer do not branch out. State ONE reason for this.
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(1 mark)
e) A leaf might take one year to decompose in a regular climate, but only six weeks
to disappear in the rainforest floor. Name TWO abiotic factors that help accelerate
the decomposition process.
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(2 marks)
f) Epiphytes such as orchids and the Crow’s Nest Fern harvest their nutrients from
the surrounding elements including air, rain and falling leaf litter. Explain why
epiphytes are not parasites.
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(1 mark)
g) The under canopy layer is mainly made up of tree trunks and small shrubs. Little
air movements occur and there is high humidity in this layer. Cormiflori trees
produce strong smelling flowers on their trunks. Explain the importance of this
adaptation.
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(1 mark)
Total
Mark
12
35
Space for Rough Work
13
Space for Rough Work
14
Space for Rough Work
15