secondary education certificate level september 2015 … · september 2015 session subject: biology...
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Index Number:___________ SEC04/1.15s
© The MATSEC Examinations Board reserves all rights on the examination questions in all examination papers set by the said Board.
MATRICULATION AND SECONDARY EDUCATION CERTIFICATE EXAMINATIONS BOARD
UNIVERSITY OF MALTA, MSIDA
SECONDARY EDUCATION CERTIFICATE LEVEL
SEPTEMBER 2015 SESSION
SUBJECT: Biology
PAPER NUMBER: I
DATE: 31st August 2015
TIME: 9:00 a.m. to 11:00 a.m.
ANSWER ALL QUESTIONS IN THIS PAPER IN THE SPACES PROVIDED
1. The table describes functions of different parts of the digestive system and related organs.
Name each part.
A muscle that controls the amount of chyme passing into the small
intestine.
The organ that produces bile.
The organ that releases trypsin.
Here, hydrochloric acid kills germs and bacteria in food.
The site of absorption of digestive products, which is facilitated
by the presence of villi.
Undigested food substances are stored temporarily in this structure
before egestion.
Pushes food into the stomach by peristalsis.
This structure carries bile into the duodenum.
Total: 8 marks
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2. Bacteria are prokaryotic cells. Their activities influence human life.
a. In the space below, draw the structure of a typical bacterial cell and label FOUR different
structures.
(3 marks)
b. Define the term prokaryotic.
_________________________________________________________________________________
(1 mark)
c. Describe the activity of each of the bacteria named below:
i) Decomposers;
_________________________________________________________________________________
ii) Nitrifying bacteria;
_________________________________________________________________________________
iii) Denitrifying bacteria.
_________________________________________________________________________________
(1, 1, 1 mark)
d. An Amoeba is a single celled organism.
i) Name the kingdom to which Amoeba belongs.
_________________________________________________________________________________
(1 mark)
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ii) Amoeba does not have a digestive system. Explain how it obtains food.
_________________________________________________________________________________
_________________________________________________________________________________
_________________________________________________________________________________
_________________________________________________________________________________
_________________________________________________________________________________
(4 marks)
Total: 12 marks
3. During a biology investigation, students had to test baby food to find out what it contained.
Students carried out some food tests and recorded their results in the table below.
a. Complete the table by filling in the empty boxes.
Test for Reagent used Colour change observed Positive/negative
result
Starch
Iodine Remained yellow
Biuret positive
Glucose
Orange-brown precipitate
(5 marks)
b. One of the tests carried out during this investigation required heating. Name this test.
_________________________________________________________________________________
(1 mark)
c. A baby’s balanced diet requires other nutrients such as calcium and fats. Explain why each
component is important for the baby’s development.
_________________________________________________________________________________
_________________________________________________________________________________
(2 marks)
d. Lack of vitamins or mineral salts in the diet can lead to deficiency diseases. Name the
deficiency disease caused by lack of:
i) Vitamin C ______________________________________________________________
ii) Iron ___________________________________________________________________
(2 marks)
Total: 10 marks
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4. The photograph below shows the leaves of the Carob tree (Ħarruba). The leaves are broad and
net-veined. The tree produces green flowers that form fruit pods with seeds.
a. Name the phylum of the Carob tree.
_________________________________________________________________________________
(1 mark)
b. Is the tree a monocot or dicot? Give ONE reason for your answer.
_________________________________________________________________________________
_________________________________________________________________________________
(1, 1 mark)
c. The leaves of the Carob tree have a leathery texture with a thick cuticle. The Carob tree is
commonly found in Malta and the Mediterranean region. Explain the importance of having a
thick cuticle.
_________________________________________________________________________________
_________________________________________________________________________________
(2 marks)
d. The Black Borer beetle, Apate monachus, is a parasite of the Carob tree. List the species name
of the Black Borer beetle.
_________________________________________________________________________________
(1 mark)
e. The local community have been asked to use pesticides to destroy this insect. Give ONE
disadvantage of using pesticides.
_________________________________________________________________________________
(2 marks)
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f. The Black Borer beetle bores holes through the phloem tissue of twigs and branches to feed.
Predict how this action affects other parts of the tree such as the roots.
_________________________________________________________________________________
_________________________________________________________________________________
(2 marks)
g. The Red Palm weevil, Rhynchophorus ferrugineus, is another parasitic insect that has been
transported unintentionally to the Maltese Islands. It lays its eggs in palm trees. Are the two
insects related? Give ONE reason for your answer.
_________________________________________________________________________________
_________________________________________________________________________________
(1, 1 mark)
Total: 12 marks
5a. In an investigation of free-living nitrogen fixing bacteria found in soil, students compared the
growth of these bacteria in two petri dishes, one with nitrogen rich agar and a second with
nitrogen free agar. Below is a top view of the two petri dishes A and B with the shaded area
showing the growth of the bacteria.
A: Petri Dish with nitrogen rich agar B: Petri Dish with nitrogen free agar
i) Describe the results obtained by this investigation.
_________________________________________________________________________________
_________________________________________________________________________________
(1 mark)
This question continues on the next page.
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ii) Give ONE explanation why growth still occurred in the petri dish with nitrogen free agar.
_________________________________________________________________________________
_________________________________________________________________________________
(2 marks)
b. Nitrogen fixing bacteria in leguminous plants are found in root nodules. Name and explain the
association between the leguminous plants and these bacteria.
_________________________________________________________________________________
_________________________________________________________________________________
_________________________________________________________________________________
(1, 2 marks)
c. Name ONE physical phenomenon that has the same effect as nitrogen fixing bacteria.
_________________________________________________________________________________
(1 mark)
d. Explain the effects on soil and crops if farmers plant wheat in their fields year after year
without rotating with leguminous plants.
_________________________________________________________________________________
(1 mark)
Total: 8 marks
6. A survey about the height of 100 students at the end of secondary school was carried out. The
results obtained are shown in the table below.
Number of students Height (cm)
10 131-140
20 141-150
50 151-160
15 161-170
5 171-180
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a. On the graph paper below, plot a histogram to show the results obtained.
(5 marks)
b. What type of variation is shown by this histogram?
_________________________________________________________________________________
(1 mark)
c. 20% of the students in this survey could not roll their tongue, even though their parents were
tongue rollers. Tongue rolling is a genetic characteristic determined by a dominant allele.
Using R to represent rolling and r to represent non-rolling, find the theoretical probability of
two rolling parents with heterozygous genotypes, to have a non-rolling child.
Parents’ genotype ________ ________
Gamete’s genotype
Offspring genotype _______ _______ _______ _______
Probability of having non-rolling child: __________________________________________
(5 marks)
Total: 11 marks
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7a. Define the term osmosis.
_________________________________________________________________________________
_________________________________________________________________________________
(2 marks)
b. Gummy bear sweets are made up of gelatine, sugar, flavouring and food colouring. The
gelatine forms a structural matrix that only allows water through.
The student put a gummy bear sweet in pure water and another one in a very strong salt
solution. The two set-ups were left overnight.
The length and the mass of the gummy bears were measured at the start and at the end of the
experiment.
i) In the table below describe the final length and mass of the gummy bear sweets placed in
water and the salt solution respectively. Use the terms decrease, increase, heavier and
lighter appropriately.
Gummy bear
measurements
Measurement at the
start of the
experiment
Description at the end of the experiment
In water In strong salt
solution
Length/ mm 20
Mass/g 5
(2 marks)
ii) Explain the predicted result of the final length of the gummy bear sweet placed in water.
_________________________________________________________________________________
_________________________________________________________________________________
(2 marks)
iii) Explain the predicted result of the final mass of the gummy bear sweet placed in the
strong salt solution.
_________________________________________________________________________________
_________________________________________________________________________________
(2 marks)
iv) What is the term that best describes the fact that gelatine ‘only allows water through’?
_________________________________________________________________________________
(1 mark)
c. Suggest ONE way how to improve the experiment.
_________________________________________________________________________________
_________________________________________________________________________________
(2 marks)
Total: 11 marks
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8. The diagram below shows two different flowers.
a. Which flower is wind pollinated? List TWO features shown in the diagram that make this
flower adapted for wind pollination.
_________________________________________________________________________________
_________________________________________________________________________________
(1, 2 marks)
b. State TWO characteristics of the pollen produced by Flower 1 that differ from the pollen
produced by Flower 2.
_________________________________________________________________________________
_________________________________________________________________________________
(2 marks)
c. Pollen grains have a haploid number of chromosomes.
i) Describe what is meant by a haploid number of chromosomes.
_________________________________________________________________________________
ii) Name ONE animal cell that is haploid and name the site in the body where it is produced.
_________________________________________________________________________________
_________________________________________________________________________________
(1, 2 marks)
d. Plants need mineral ions from the soil to grow and flower.
i) Name the process by which mineral ions enter root hair cells.
_________________________________________________________________________________
ii) Name ONE chemical element important for plant growth.
_________________________________________________________________________________
(1, 1 mark)
Total: 10 marks
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9. The photograph below shows a garigue ecosystem.
a. Mark with a tick () which of the descriptions describe a garigue ecosystem.
Low growing shrubs
Resulting from degradation of woodland
Small trees and large shrubs
Pockets of soil with succulent plants
(2 marks)
b. The Mediterranean Chameleon is a reptile that survives in garigue habitats. Camouflage and
slow movements help it catch its prey. It feeds on insects. It lays its eggs in a hole in the
ground.
i) Describe the skin of reptiles.
_________________________________________________________________________________
(1 mark)
ii) Describe the eggs of reptiles.
_________________________________________________________________________________
(1 mark)
iii) Distinguish between predator and prey.
_________________________________________________________________________________
_________________________________________________________________________________
_________________________________________________________________________________
(2 marks)
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c. The sea daffodil is a plant that lives close to the sea in sand dunes or saltmarshes. It propagates
asexually by bulbs. Bulbs are rich in nutrients especially sugars. Explain why these structures
are a sugar food store.
_________________________________________________________________________________
_________________________________________________________________________________
(2 marks)
Total: 8 marks
10. The flow chart summarises the process by which butter is produced from raw milk.
a. Raw milk is generally obtained from cows. Butter may also be produced from the milk of
buffalo, camel, goat, ewe and mare.
i) Name the vertebrate group to which all the organisms mentioned belong.
_________________________________________________________________________________
(1 mark)
ii) Give a reason for your choice in part a(i).
_________________________________________________________________________________
_________________________________________________________________________________
(2 marks)
This question continues on the next page.
Raw milk
Raw skimmed milk
Raw cream Pasteurised milk Pasteurised
Addition of bacteria
that perform lactic
acid fermentation
Ripened cream
Aging and further
processing Raw butter
Finished butter
Working and salting
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b. Pasteurisation involves heating the cream to 95°C. Explain what happens to the enzymes and
any microorganisms present in milk during this process.
_________________________________________________________________________________
_________________________________________________________________________________
(2 marks)
c. Bacteria that perform lactic acid fermentation are added to the pasteurised cream.
i) Name the sugar in milk that is fermented to form lactic acid.
_________________________________________________________________________________
(1 mark)
ii) State whether oxygen is used during lactic acid fermentation.
_________________________________________________________________________________
(1 mark)
iii) State how the pH value of the mixture changes during this part of the butter making
process.
_________________________________________________________________________________
(1 mark)
d. Butter is rich in fat. Give ONE advantage and ONE disadvantage of including butter in one’s
diet.
_________________________________________________________________________________
_________________________________________________________________________________
_________________________________________________________________________________
(2 marks)
Total: 10 marks
SEC04/2B.15s
© The MATSEC Examinations Board reserves all rights on the examination questions in all examination papers set by the said Board.
MATRICULATION AND SECONDARY EDUCATION CERTIFICATE EXAMINATIONS BOARD
UNIVERSITY OF MALTA, MSIDA
SECONDARY EDUCATION CERTIFICATE LEVEL
SEPTEMBER 2015 SESSION
SUBJECT: Biology
PAPER NUMBER: IIB
DATE: 31st August 2015
TIME: 4:00 p.m. to 6:00 p.m.
Write your answers on the booklet provided. Write down the number of the questions you
answer, on the first page of your answer booklet.
Please note that for question 1 of this paper you need the graph paper in the booklet.
Answer any FOUR questions.
1. Smoking causes the majority of lung cancers whether it is from smokers or from passive
smoking.
a. i) Define passive smoking. (1 mark)
ii) One symptom of lung cancer is shortness of breath (breathlessness). Explain how the
lungs are affected by lung cancer to cause breathlessness. (2 marks)
b. The table below shows the total number of Maltese citizens diagnosed with lung cancer
between the years 2004 to 2012.
Year of diagnosis Total number of Maltese diagnosed with lung
cancer
2004 109
2006 146
2008 144
2010 207
2012 196
i) On the graph paper provided (use the 2 mm grid scale), draw a line graph of the total
number of Maltese diagnosed with lung cancer (y-axis) against the year of diagnosis (x-
axis). Join the points using straight lines. (6 marks)
ii) In 2012, 66 of the Maltese citizens diagnosed with lung cancer were females. Calculate
the percentage of females with lung cancer in 2012. (2 marks)
c. Smoking also causes emphysema.
i) Draw a labelled diagram of an alveolus showing gaseous exchange. In your diagram,
clearly indicate the direction of oxygen and carbon dioxide flow across the membrane.
(4 marks)
ii) Give a characteristic feature of a gaseous exchange surface affected by emphysema.
(2 marks)
iii) List THREE characteristic symptoms of emphysema. (3 marks)
This question continues on the next page.
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d. A concentration gradient is necessary for diffusion of oxygen and carbon dioxide in gaseous
exchange. Describe how a concentration gradient is created in:
i) lungs in humans;
ii) gills in fish. (2, 3 marks)
Total: 25 marks
2. The Government experimental farm in Gozo organises visits for secondary school students
regarding hands on farming. The farm has two main sections. A section has greenhouses and
an area where endemic (found only on the Maltese Islands) plants are grown. A second section
has several farm animals including the Maltese Ox (Gendus) and the Black Maltese Chicken.
a. One local plant species found at the farm is the Sandarac Gum tree (Siġra ta’ Għargħar). The
plant is a gymnosperm.
i) The Sandarac Gum tree does not produce flowers. List the structure that produces the
gametes. (1 mark)
ii) Describe the leaves of gymnosperms. (2 marks)
b. Another tree in this section is the Holm Oak (Siġra tal-Ballut). The tree has leaves that are dark
green on the top and more whitish on the underside of the leaf. Give ONE reason for the
whitish colour on the underside of the leaf. (2 marks)
c. The Black Maltese chicken has been close to extinction in the last years. It has black feathers
and lays white eggs.
i) Name the phylum of the Black Maltese chicken. (1 mark)
ii) Birds are endothermic. Define endothermic. (2 marks)
iii) Explain how birds use their feathers to reduce heat loss from the body in cold weather.
(2 marks)
iv) The shell of a bird’s egg whilst being hard is porous to oxygen. Explain how these two
properties are important for the development of the chick embryo. (2 marks)
d. In an article in a local newspaper the following was written on the Black Maltese chicken.
‘Chickens were ideal for an organic way of getting rid of the fruit fly. “The flies lay their eggs
in the soil – if you have a Maltese Black, they’ll nip it at worming stage.’ Times of Malta 9.07.2012
i) Explain what is meant by ‘organic way’. (2 marks)
ii) The fruit fly is an insect. Give ONE characteristic feature of the class insect. (1 mark)
iii) What is the author of this article referring to when writing ‘worming stage’. (2 marks)
e. Another animal at the farm is the Maltese Ox. This animal was also close to extinction.
i) Define the term extinction. (2 marks)
ii) The Maltese ox is a ruminant. Give TWO adaptations of the dentition of ruminants and
explain the importance of these adaptations. (2, 2 marks)
iii) Is the length of the gut of a herbivore longer or shorter than that of a carnivore of similar
size? Give ONE reason for your answer. (2 marks)
Total: 25 marks
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3a. The following equation summarises the process of photosynthesis.
i) Name ONE type of plant cell that performs photosynthesis and state where it is found in
a plant. (2 marks)
ii) Name ONE type of plant cell that does not perform photosynthesis. Give ONE reason for
your answer. (1, 1 mark)
iii) What are the roles of light and chlorophyll in photosynthesis? (2 marks)
iv) Describe what happens to the TWO products produced in the process. (2 marks)
b. Give ONE reason for each of the following structures.
i) Larger and broader leaves have a higher rate of photosynthesis than smaller and narrower
leaves. (2 marks)
ii) Plants grow more slowly in the shade. (2 marks)
iii) Plants grow faster in a carbon dioxide enriched atmosphere. (2 marks)
iv) Plants have a faster rate of photosynthesis at noon on a day in June than on a day in
January. (2 marks)
c. Plants take up carbon dioxide from the air through the stomata. They also lose water vapour
through the stomata. Therefore plants strike a balance between the rate of photosynthesis and
the rate of transpiration.
Describe how plants use stomata to allow photosynthesis and also reduce the amount of water
transpired. (2 marks)
d. Explain how the following leaf characteristics help to reduce water loss.
i) Sunken stomata; (2 marks)
ii) Needle like leaves. (2 marks)
e. Bryophytes (mosses) have simple leaves and rhizoids instead of roots.
i) Describe the habitat of mosses. (1 mark)
ii) Give TWO reasons why mosses can only survive in the habitat described in e(i).(2 marks)
Total: 25 marks
4a. Distinguish between:
i) Habitat and community. (3 marks)
ii) Food chains and food webs. (4 marks)
iii) Chlorofluorocarbons (CFC) and carbon dioxide (CO2) as harmful pollutants. (4 marks)
iv) Deforestation and desertification. (4 marks)
b. Explain the harm caused to the environment by the following:
i) Eutrophication; (4 marks)
ii) Dumping of rubbish in the countryside; (4 marks)
iii) Increased lead content in the soil. (2 marks)
Total: 25 marks
carbon dioxide + water glucose + oxygen
light
chlorophyll
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5. The Great Barrier reef, located off the coast of Queensland, Australia, is the largest coral reef
system. There are about 350 different coral species on the reefs, a large biodiversity of
organisms as well as several ecosystems.
a. Define the term biodiversity. (2 marks)
b. Coral are primitive animals of the phylum Cnidaria (coelenterates). Give ONE characteristic
feature of cnidaria. (2 marks)
c. The reef supports several different aquatic species from vertebrates to many invertebrates.
i) The giant clam is a reef mollusc. Give ONE characteristic feature of molluscs. (2 marks)
ii) Different species of lobsters, shrimps and crabs are also found on the reef. These all have
five pairs of jointed appendages. Name the class to which the above mentioned
organisms belong. (1 mark)
iii) A diver observed three different species of worms in the sand. Two of the worms had
segmented bodies while the other worm had a thread like body. Give the TWO phyla of
these worms. (2 marks)
d. Below are five fish of which the coral reefs are their habitat.
Use the following dichotomous key to identify the five fish found above.
i) Fish shape is long and skinny……………………………………….Spotted Moray Eel
Fish shape is not long and skinny ……………………………………….……..Go to (ii)
ii) Fish has long whip like tail………………………..…………….…..Spotted Eagle Ray
Fish has small tail………………………………………………………………Go to (iii)
iii) Fish has spots on its body…………………………………………..…Spotted Goat fish
Fish has stripes on its body……………………………………………………..Go to (iv)
iv) Fish has a V-shaped tail…………………………..…………………..…….Squirrel fish
Fish has a tail with blunt end………..……………………………..Glass eyed Snapper
Name each of the organisms A to E. (5 marks)
e. i) Corals produce bud polyps that detach from the parent polyp and form new colonies. The
buds are genetically identical to the parent. Name the type of reproduction that produces
bud polyps. (1 mark)
A B C
D E
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ii) Coral also produce larvae that are not genetically identical to their parents. Large
numbers are produced each reproductive cycle. Why do coral produce large numbers of
larvae? (1 mark)
f. In 2012, scientists discovered that two separate viruses infect protists that live in coral and
contribute to coral health and growth.
i) Draw a labelled diagram of a virus. (4 marks)
ii) Explain why a protist is defined as a living organism while a virus is borderline between
living and non-living. (4 marks)
iii) These protists are plant-like protists. Name ONE structure present in these protists that
are not present in an animal-like protist. (1 mark)
Total: 25 marks
6. A cat’s nervous system is responsible for its reactions to changes in the surrounding
environment. The diagram shows the cat’s reflex arc.
a. Identify the stimulus in the picture which gave rise to the reflex action. (1 mark)
b. Define the term reflex arc. (2 marks)
c. Name the parts labelled A, B and C and describe the function of each part. (6 marks)
d. The brain is an important organ in the central nervous system. The cerebrum is highly folded
and protected by the skull.
i) Describe the biological importance of the folding in the cerebrum. (2 marks)
ii) Name the structures that protect the spinal cord. (1 mark)
e. The skin is sensitive to the changes in the surrounding temperature.
i) State TWO mechanisms the skin adopts in order to decrease heat loss by the body.
(2, 2 marks)
ii) Name ONE function of sebaceous glands in the skin. (2 marks)
f. Plants are unable to move from place to place. Thus, sensitivity to their surroundings is vital
for their growth and survival. Plant shoots are positively phototropic and negatively geotropic.
i) Define the term geotropic. (2 marks)
ii) Explain using diagrams what happens to a shoot when exposed to unidirectional light.
(5 marks)
Total: 25 marks
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7a. i) Explain why enzymes are referred to as biological catalysts. (2 marks)
ii) Use the lock and key hypothesis to explain why enzymes are specific. Include a clearly
labelled diagram in your answer. (3 marks)
b. A student investigated the effect of changing the concentration of trypsin on the lining of the
photographic film. The lining is made up of gelatine. The apparatus used was set up as shown
below.
i) Describe how trypsin acts on the gelatine lining of the photographic film. (2 marks)
ii) All the concentrations of trypsin were produced from the original 100% trypsin
concentration. Briefly describe how this is done. (2 marks)
iii) Explain why all the pieces of the photographic film used should have the same size.
(2 marks)
iv) Explain why the temperature is kept constant and at 35°C throughout the experiment.
(3 marks)
v) The following sketch shows the shape of the graph obtained at the end of the experiment.
Describe and explain the relationship between the rate of reaction and the concentration
of trypsin. (3 marks)
c. Sketch a graph to show how the rate of reaction catalysed by trypsin varies with changing pH.
Clearly indicate the optimum pH for trypsin. (4 marks)
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d. In another experiment a student investigated whether different fruits have protein digesting
enzymes. The student prepared four test tubes as follows:
Tube Contents Result Conclusion
1 3cm
3 pineapple juice + 10cm
3
dissolved gelatine
Gelatine remains
liquid Enzymes present
2 3cm
3 kiwi juice + 10cm
3
dissolved gelatine
Gelatine remains
liquid Enzymes present
3 3cm
3 orange juice + 10cm
3
dissolved gelatine
Gelatine becomes
solid Enzymes absent
4 3cm
3 apple juice + 10cm
3
dissolved gelatine
Gelatine becomes
solid Enzymes absent
Given that gelatine will set and become a solid after allowing time to set, explain the results of
the experiment. (4 marks)
Total: 25 marks
Please turn the page for Question 8.
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8. A student’s heart has a ventricular septal defect. This condition is shown in the diagram
below. Doctors realised the student had this problem because they heard a heart murmur when
they listened to his heart beat with a stethoscope.
a. i) Describe the problem caused by the space in the student’s heart. (2 marks)
ii) Describe ONE symptom of this condition. (2 marks)
b. Name the blood vessel which:
i) brings deoxygenated blood from the body to the heart. (1 mark)
ii) brings oxygenated blood from the lungs into the heart. (1 mark)
iii) carries oxygenated blood to the liver. (1 mark)
c. Blood is an important transport medium in the human body. It transports specialised cells and
other substances.
i) Name TWO substances carried by the blood plasma. (2 marks)
ii) Explain how the structure of red blood cells is related to their function. (3 marks)
iii) Describe the function of platelets in blood. (2 marks)
d. Some small ventricular defects close on their own, after birth.
i) Give ONE physical reason why a small space in the septum does not increase in size.
(1 mark)
ii) Explain, using the appropriate terms, how these defects close on their own. (2 marks)
e. The wall of the left side of the heart is thicker than the right side. Explain the importance of
this. (2 marks)
f. Blood is transported in the body through blood vessels. In the form of a table, state THREE
differences between arteries and veins. (6 marks)
Total: 25 marks