Download RHS Past Paper R2101 - Plant Classification, Structure and Function

Including Examiners Comments
R2101
PLANT CLASSIFICATION, STRUCTURE AND FUNCTION
Level 2
Monday 10 February 2014
09:30 – 10:30
Written Examination
Candidate Number: …………………………………………………………………
Candidate Name: ……………………………………………………………………
Centre Number/Name: ……………………………………………………………..
IMPORTANT – Please read carefully before commencing.
i)
The duration of this paper is 60 minutes.
ii)
ALL questions should be attempted.
iii)
EACH question carries 10 marks.
iv)
Write your answers legibly in the lined space provided. It is NOT
necessary that all lined space is used in answering the questions.
v)
Use METRIC measurements only.
vi)
Use black or blue ink only. Pencil can be used for drawings only.
vii)
Where plant names are required, they should include genus, species
and where appropriate, cultivar.
viii)
Where a question requires a specific number of answers; only the first
answers given that meet the question requirement will be accepted,
regardless of the number of answers offered.
ix)
Please note, when the word ‘distinct’ is used within a question, it means
that the items have different characteristics or features.
Ofqual Unit Code K/505/2967
Please turn over/…..
ANSWER ALL QUESTIONS
MARKS
Q1
State FIVE differences between flowering plants and conifers by completing
the table below.
Flowering plants
Conifers
1
2
2
2
3
2
4
2
5
2
Total Mark
Please see over/…..
2
MARKS
Q2
a)
Label EACH of the following root tissues on the diagram below:
i)
ii)
iii)
iv)
v)
vi)
epidermis;
vascular cambium;
endodermis;
phloem;
cortex;
pericycle.
6
Transverse section through a young dicotyledonous root
b)
State ONE function of FOUR of the tissues listed in a).
Root tissue
4
Function
1
2
3
Total Mark
4
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3
MARKS
Q3
a)
State the equation for photosynthesis in words.
2
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b)
State how levels of mineral nutrients affect the rate of photosynthesis.
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c)
Describe the uptake of mineral nutrients by root cells.
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Total Mark
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MARKS
Q4
a)
State TWO primary functions of the root.
2
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b)
Complete the table below for TWO other functions for which roots are adapted.
Function
Description of adaptation
Plant example
1
4
2
4
Total Mark
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5
MARKS
Q5
a)
State what is meant by the term ‘transpiration’.
1
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b)
Describe how THREE NAMED leaf adaptations reduce water loss, giving a
NAMED plant example for EACH.
1………………………………………………………………………………………….
3
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Total Mark
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6
MARKS
Q6
a)
Identify TWO requirements for aerobic respiration.
2
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b)
State how temperature affects the rate of aerobic respiration.
3
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c)
Describe the significance of aerobic respiration in seed storage.
5
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Total Mark
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MARKS
Q7
a)
State ONE function of the flower.
1
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b)
Name the flower parts labelled on the diagram below.
5
A typical monocotyledonous flower
c)
State TWO differences between monocotyledonous and dicotyledonous
flowers by completing the table below.
Monocotyledonous flower
4
Dicotyledonous flower
1
1
2
2
Total Mark
Please see over/…..
8
MARKS
Q8
a)
Name the stage of the life cycle in which the following takes place:
i)
ii)
reproductive growth;
vegetative growth.
1
1
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b)
State the difference between EACH of the following terms:
i)
ii)
‘evergreen’ and ‘semi evergreen’ plants;
‘shrub’ and ‘tree’.
2
2
i)………………………………………………………………………………………...
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ii)……………………………………………………………………………………….
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c)
Give ONE NAMED plant example for EACH of the terms given in b).
4
evergreen……………………………………………………………………………...
Total Mark
semi evergreen……………………………………………………………………….
shrub…………………………………………………………………………………..
tree……………………………………………………………………………………..
Please turn over/…..
9
MARKS
Q9
a)
Draw a fully labelled diagram to show the external features of a
dicotyledonous leaf.
5
External features of a dicotyledonous leaf
b)
Describe the following leaf types:
i)
ii)
1
2
simple;
compound.
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c)
NAME a plant example for EACH of the leaf types described in b).
2
Total Mark
Simple leaf…………………………………………………………………………….
Compound leaf……………………………………………………………………….
Please see over/…..
10
MARKS
Q10
State TWO functions of EACH of the seed parts listed by completing the table
below.
Seed part
Function
Testa
2
Cotyledon
2
Micropyle
2
Plumule
2
Hilum
2
Total Mark
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©These questions are the property of the Royal Horticultural Society.
They must not be reproduced or sold.
The Royal Horticultural Society, Wisley, Woking, Surrey GU23 6QB.
Charity Registration Number: 222879/SC038262
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R2101
PLANT CLASSIFICATION, STRUCTURE AND FUNCTION
Level 2
Monday 10 February 2014
Candidates Registered
Candidates Entered
Candidates Absent
Candidates Deferred
Candidates Withdrawn
942
783
97
39
23
83.12%
10.30%
4.14%
2.44%
Total Candidates Passed
Passed with Commendation
Passed
Failed
640
341
299
143
81.74%
43.55%
38.19%
18.26%
Senior Examiner’s Comments:
1
Candidates should be able to demonstrate a good range of plant knowledge
and be able to give accurately named plant examples where appropriate.
Common names and generic names are often too vague and cannot be
rewarded in the positive manner that genus, species and where appropriate,
variety/cultivar can. This is particularly important when answering questions
relating to particular (named) plant(s). Marks can only be awarded for these
narratives where the example(s) are correctly and fully identified.
2
Candidates must be able to display accurate knowledge of the technical terms
and concepts detailed in the syllabus, in the context of horticulture and also
be aware that wider interpretation will not be rewarded. The examination
should be regarded as a possible introduction to higher level studies, which
will only be open to those who are in possession of a clear understanding of
the horticultural terms and concepts which are current.
3
The introductory rubric given on the first page of each question paper should
be read carefully by candidates. At each examination there are a significant
number of candidates who ignore or misread the instructions given and
consequently may not perform as well as they could have done.
4
Candidates should pace themselves during each paper. The most successful
candidates allow sufficient time to read the question thoroughly before
answering it and also take time to read through their answers. They should
take care to write as legibly as possible, so that the examiner is in no doubt
about what is intended.
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5
Candidates need to interpret key words within questions, particularly those
such as ‘state’, ‘list’ and ‘describe’. Questions requiring descriptions or
explanations obviously require a more detailed answer than those requiring a
list.
6
It is important to ensure that responses to questions are to the point.
Candidates should bear in mind that small sketches might be used to
convey information more succinctly than words.
7
Successful candidates ensure that their answers are focused and to the point.
It is disappointing when they cannot be rewarded for their efforts because the
answer is irrelevant to the particular question. Candidates should take note of
the mark allocation for specific sections and allocate their time and efforts
accordingly.
8
Diagrams can enhance an answer and where appropriate can replace
detailed descriptions. They should be large, clear and well annotated,
ensuring that labels are properly attached to the features they describe.
Diagrams should preferably be in pencil. Colour may be used successfully but
only where it is relevant to the answer.
9
In each examination it is clear that some candidates are ill prepared to answer
papers of the type set. It is essential that candidates have the opportunity to
practice questions. Ideally some papers should be answered in a time
constrained situation. Appropriate feedback must, in any case be provided.
10
Candidates should be aware of the reading list of suggested books for the
RHS Level 2 Certificate in The Principles of Plant Growth, Propagation and
Development which is available from the Qualifications Section and can also
be found on the RHS website together with past papers.
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Overall Examiners’ Comments:
Q1
State FIVE differences between flowering plants and conifers by completing
the table below.
MARKS
Flowering plants
Conifers
1
2
2
2
3
2
4
2
5
2
Q1)
The best candidates were able to identify and fully state a suitable
difference between flowering plants and conifers. They did not confuse
flowering plants and conifers with monocotyledons and dicotyledons.
Suitable differences related to the structure of leaves and stems,
reproductive structures and methods, numbers of species/families, life
cycles and habitats occupied.
Marks were awarded to candidates who were aware that flowering plants
can have a range of attributes for a particular difference e.g.






Flowers can be pollinated by many vectors including wind, not just
insects, so not all are brightly coloured or have nectar whereas conifers
are only wind pollinated.
Flowers can be hermaphrodite, monoecious or dioecious whereas
conifers can never be hermaphrodite.
Flowering plants have a range of leaf shapes whereas conifers have
reduced leaves e.g. needles or scale leaves.
Flowering plants include both evergreen and deciduous species whereas
conifers are mostly evergreen.
Flowering plants can be both woody and herbaceous whereas conifers
are woody.
Flowering plants have a range of life cycles (annual, biennial, perennial)
whereas conifers are perennials.
15
Q2
a)
Label EACH of the following root tissues on the diagram below:
i)
ii)
iii)
iv)
v)
vi)
MARKS
epidermis;
vascular cambium;
endodermis;
phloem;
cortex;
pericycle.
6
Transverse section through a young dicotyledonous root
b)
State ONE function of FOUR of the tissues listed in a).
Root tissue
Function
1
2
3
4
Q2a) Candidates who provided labels that were accurate and carefully drawn,
showing exactly which tissue was indicated were awarded full marks.
Marks could not be awarded for tissues that were not asked for e.g. xylem.
Q2b) The best candidates stated one function only for the chosen tissues,
providing detailed answers e.g.






Epidermis – encloses tissues; produces root hairs; provides protection
from pests and diseases but does not prevent water loss in roots.
Vascular cambium – responsible for secondary thickening; produces new
xylem and phloem.
Endodermis – Controls water and mineral uptake.
Phloem – transports sugars and minerals.
Cortex – a packing tissue that stores starch and produces energy.
Pericycle – gives rise to lateral roots.
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4
MARKS
Q3
a)
State the equation for photosynthesis in words.
2
b)
State how levels of mineral nutrients affect the rate of photosynthesis.
4
c)
Describe the uptake of mineral nutrients by root cells.
4
Q3a) Full marks were awarded to those candidates who stated the four materials
involved in photosynthesis as; water plus carbon dioxide which produce
carbohydrates and oxygen and did not confuse the process with respiration.
Q3b) The best candidates considered the wording of the question carefully. They
stated how the rate of photosynthesis is affected by mineral nutrients rather
than other factors such as temperature and did not describe the role of
mineral nutrients in other processes such as respiration or transpiration.
Marks could not be awarded to candidates who stated that levels of mineral
nutrients affect the rate of photosynthesis without saying how they affect it.
Candidates who understood that mineral nutrients can both increase and
decrease the rate of photosynthesis, depending on their level, gained full
marks. They stated that both very low levels and very high levels of mineral
nutrients reduce the rate of photosynthesis, showing that there is an optimum
level for photosynthesis.
Marks were also awarded where candidates named particular nutrients which
influence photosynthesis e.g. magnesium, iron and nitrogen, for stating their
role in photosynthesis and for linking deficiency to chlorosis and excess to
plasmolysis both of which will reduce the rate of photosynthesis.
Q3c) Candidates who described the uptake of minerals by cells rather than their
movement through the plant as a whole were awarded full marks. The best
candidates described the uptake of minerals by active transport, correctly
stating that this is an energy requiring and selective process across the cell
membrane against a concentration gradient.
Candidates who confused mineral uptake with water uptake and incorrectly
stated that minerals are absorbed by osmosis could not be awarded any
marks.
Marks were also awarded to candidates who stated that minerals are
dissolved in soil water or foliar feeds, for stating the role of root hairs, the
endodermis and the casparian strip and for stating that some minerals in
specific circumstances may be taken into cells by simple diffusion.
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MARKS
Q4
a)
State TWO primary functions of the root.
b)
Complete the table below for TWO other functions for which roots are adapted.
Function
Description of adaptation
2
Plant example
1
4
2
4
Q4a) The majority of candidates were able to state that the primary function of roots are;
anchorage and uptake of water and nutrients and were awarded full marks.
Q4b) Candidates who filled in the table correctly according to the headings in the
columns by starting with the function of the adaptation rather than naming or
describing the adaptation were awarded full marks. Suitable functions of roots and
their adaptations include; storage – root tubers e.g. Dahlia pinnata, swollen tap
roots e.g. Daucus carota, water storage roots e.g. Odontoglossum crispum,
climbing – adventitious roots on stems e.g. Hedera helix, support – prop roots e.g.
Zea mays, vegetative spread – suckers e.g. Rumex acetosella, photosynthesis –
aerial velamen roots of orchids e.g. Phalaenopsis schilleriana, respiration in
anaerobic conditions – pneumatophores e.g. Avicennia nitida.
The best candidates provided full details e.g. tubers storing starch/carbohydrates
rather than food, adventitious prop roots at the base of stems, adventitious roots
enabling the plant to grow towards the light for photosynthesis, suckers arising
from adventitious buds and pneumatophores extending above the water enabling
the transfer of oxygen from the aerial parts of the plant to submerged roots in
waterlogged soils.
Marks could not be awarded where candidates confused root adaptations with
other plant structures e.g. stem adaptations i.e. tubers, rhizomes and corms or leaf
adaptations i.e. bulbs.
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MARKS
Q5
a)
State what is meant by the term ‘transpiration’.
b)
Describe how THREE NAMED leaf adaptations reduce water loss, giving a
NAMED plant example for EACH.
1
1………………………………………………………………………………………….
3
2………………………………………………………………………………………….
3
3………………………………………………………………………………………….
3
Q5a) The majority of candidates were able to state that transpiration is the
evaporation of water or loss of water from plant surfaces and were awarded
full marks.
Q5b) Candidates who described a range of leaf adaptations to reduce water loss
and provided suitable plant examples gained full marks. Leaf adaptations
described included; leaf hairs which trap water vapour close to the leaf
which increases the humidity e.g. Stachys byzantina, needles or spines
reduce the leaf surface area and therefore reduce water loss e.g. Opuntia
polycantha, rolled leaves increase the humidity within the leaf and reduce
the surface area e.g. Ammophila arenaria, (Pinus species were not
accepted as an example of rolled leaves although Rosmarinus officinalis
was accepted as it has an inrolled margin), thick cuticle of wax (cutin)
waterproofs the leaf, stomato open at night rather than in the day when
temperatures are higher e.g. Ilex aquifolium and silver leaves reflect
radiation from the sun and reduce the leaf temperature e.g. Lavandula
angustifolia.
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MARKS
Q6
a)
Identify TWO requirements for aerobic respiration.
2
b)
State how temperature affects the rate of aerobic respiration.
3
c)
Describe the significance of aerobic respiration in seed storage.
5
Q6a) Most candidates identified oxygen/air and carbohydrates/sugar/starch/glucose as
the two requirements for aerobic respiration and gained full marks.
Q6b) Candidates who were able to state the changes in the rate of respiration as
temperature increases were awarded full marks. The rate of respiration increases
with increasing temperature up to an optimum after which the rate decreases.
Marks were awarded to candidates who gave suitable temperatures e.g. 5ºC
(minimum below which respiration is very slow), 30ºC (optimum) and 40ºC
(maximum temperature above which respiration ceases) depending on the species.
Graphical depictions were also accepted if appropriately labelled.
Candidates also gained marks for stating the reasons why the respiration rate is
affected e.g. at high temperatures respiratory enzymes are inactivated.
Q6c) The best candidates understood the relevance between storage time and
respiration rate i.e. the lower the respiration rate the longer the storage time and
vice versa. Descriptions included how lower respiration rates can be achieved by
lowering temperature, reducing seed moisture content and humidity in store or
increasing carbon dioxide/reducing oxygen in the storage atmosphere.
Marks were also awarded to candidates who described suitable methods to
achieve the above e.g. refrigeration, sealing seed packets and providing dry
storage with silica gel and stating that seeds continue to respire while in storage
and use up their energy reserves.
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MARKS
Q7
a)
State ONE function of the flower.
1
b)
Name the flower parts labelled on the diagram below.
5
A typical monocotyledonous flower
c)
State TWO differences between monocotyledonous and dicotyledonous
flowers by completing the table below.
Monocotyledonous flower
Dicotyledonous flower
1
1
2
2
Q7a) The majority of candidates were able to state a function of a flower. Suitable
answers included; attracting pollinators, producing a seed/fruit/embryo or organ of
sexual reproduction.
Q7b) Full marks were awarded to candidates who correctly named the flower parts on
the diagram of the monocotyledonous flower. These were; tepal, style, receptacle,
ovule and anther.
Marks could not be awarded for petal as the diagram was of a monocotyledonous
flower.
Q7c) The best candidates were able to state suitable differences between
monocotyledonous and dicotyledonous flowers. These included; differences in the
number of flower parts, the presence of tepals compared to petals and pollen
structure and gained full marks.
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4
MARKS
Q8
a)
Name the stage of the life cycle in which the following takes place:
i)
ii)
b)
1
1
State the difference between EACH of the following terms:
i)
ii)
c)
reproductive growth;
vegetative growth.
‘evergreen’ and ‘semi evergreen’ plants;
‘shrub’ and ‘tree’.
Give ONE NAMED plant example for EACH of the terms given in b).
evergreen……………………………………………………………………………...
semi evergreen……………………………………………………………………….
shrub…………………………………………………………………………………..
tree……………………………………………………………………………………..
Q8a) Most candidates were able to name the stages in the life cycle where
specific growth takes place and were awarded full marks.
i)
ii)
reproductive growth occurs in the mature or adult phase
vegetative growth occurs in the juvenile phase.
Q8b) Candidates who stated the differences between the specific terms
succinctly gained full marks.
i)
ii)
an evergreen plant retains its leaves all year round whereas a
semi evergreen plant retains its leaves all year round but can
lose them in severe weather conditions.
a shrub has multiple stems from ground level whereas a tree
has a single stem/trunk/bole.
Marks could not be awarded for the words; branches or trunk without
specifying their position as they did not provide a clear difference
between a shrub and a tree.
Q8c) Candidates who gave the full botanical name of correct plant examples
were awarded full marks.
i)
ii)
iii)
iv)
evergreen – Ilex aquifolium, Elaeagnus x ebbingei
semi evergreen – Ligustrum ovalifolium, Cotoneaster
horizontalis
shrub – Choisya ternata, Viburnum tinus
tree – Betula pendula, Quercus robur
Marks could not be awarded to candidates who gave a genus only if it
contained evergreen and semi evergreen species e.g. Quercus or species
that could be classed as trees or shrubs e.g. Acer.
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2
2
4
MARKS
Q9
a)
Draw a fully labelled diagram to show the external features of a
dicotyledonous leaf.
5
External features of a dicotyledonous leaf
b)
Describe the following leaf types:
iii)
iv)
c)
1
2
simple;
compound.
NAME a plant example for EACH of the leaf types described in b).
2
Simple leaf…………………………………………………………………………….
Compound leaf……………………………………………………………………….
Q9a) Full marks were awarded to candidates who drew a clearly labelled diagram of the
external features of a dicotyledonous leaf noting the exact position of five features
e.g. axillary bud, petiole, leaf blade or lamina, midrib, lateral veins, margin, leaf tip,
leaf base and axil.
Marks could not be awarded where a label indicating the leaf lamina was pointing
to the leaf margin.
Candidates who drew a cross section of a leaf showing the internal structure of a
leaf could only be awarded marks for labelling the epidermis or the stomata.
Q9b) The best candidates gained full marks for describing the leaf types as;
i)
ii)
a simple leaf has one blade or lamina
a compound leaf has a lamina divided into leaflets
Candidates who described the position of the axillary bud at the base of the petiole
and provided labelled diagrams showing simple and compound leaves and their
axillary buds were awarded marks.
The best candidates also described pinnate and palmate compound leaves.
Q9c) Full marks were awarded to candidates who gave correct plant examples for each
leaf type e.g. Carpinus betulus has a simple leaf and Rosa rugosa has a compound
leaf.
Marks could not be awarded to candidates who confused plants bearing compound
palmate leaves e.g. Aesculus hippocastanum with those bearing simple palmate or
lobed leaves e.g. Acer palmatum. Similarly some candidates confused compound
pinnate leaves e.g. Wisteria sinensis with simple leaves showing pinnate venation
e.g. Laurus nobilis.
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MARKS
Q10
State TWO functions of EACH of the seed parts listed by completing the table
below.
Seed part
Function
Testa
2
Cotyledon
2
Micropyle
2
Plumule
2
Hilum
2
Q10) Most candidates were able to state two functions in detail for each of the
seed parts rather than describing their structure and were awarded full
marks. Suitable functions included;
Testa – protects the embryo from disease/damage; may impose
dormancy.
Cotyledon – stores carbohydrate and provides energy to the embryo;
may photosynthesise in epigeal germination.
Micropyle – enables entry of the pollen tube to deliver male gametes for
fertilisation; enables entry of water to trigger germination.
Plumule – gives rise to young shoot; produces leaves for
photosynthesis.
Hilum – provides point of attachment of ovule to ovary; prevents entry of
pathogens once seed has detached.
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