R2101 PLANT CLASSIFICATION, STRUCTURE AND FUNCTION

Transcription

1 Including Examiners Comments R0 PLANT CLASSIFICATION, STRUCTURE AND FUNCTION Level Monday 4 June 0 09:0 0:0 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) iii) iv) ALL questions should be attempted. EACH question carries 0 marks. 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) vii) viii) ix) Use black or blue ink only. Where plant names are required, they should include genus, species and where appropriate, cultivar. 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. Please note, when the word distinct is used within a question, it means that the items have different characteristics or features. Ofqual Unit Code H/60/007 Please turn over/..

2 ANSWER ALL QUESTIONS Q a) State what is meant by EACH of the following terms: i) genus; ii) species. b) State SIX benefits of a universal system for naming plants, rather than using common names Total Mark Please see over/..

3 Q a) Name EACH of the features indicated on the diagram below. 5 Internal structure of a dicotyledonous leaf b) Describe the pathway of water movement through the leaf to the air. 5 Total Mark Please turn over/..

4 Q a) Name the site of aerobic respiration in the cell. b) State the basic word equation for EACH of the following processes: i) aerobic respiration; ii) anaerobic respiration. c) State how the efficiency of respiration is affected by: i) aerobic conditions; ii) anaerobic conditions. Total Mark Please see over/.. 4

5 Q4 a) Label EACH of the following cell components on the diagram below: i) cell membrane; ii) nucleus; iii) cytoplasm; iv) vacuole; v) cell wall. Basic plant cell b) State ONE function for EACH of the cell components listed in a). 5 Total Mark Please turn over/.. 5

6 Q5 a) Define the term fruit. b) List THREE ways in which fruits can be distributed. c) State what is meant by EACH of the following fruit types: i) dehiscent; ii) indehiscent; iii) succulent. d) Name ONE example for EACH fruit type listed in c): i) dehiscent; ii) indehiscent; iii) succulent. Total Mark Please see over/.. 6

7 Q6 a) State what is meant by the term pollination. b) State what is meant by EACH of the following terms: i) self-pollination; ii) cross-pollination. c) Describe FIVE characteristics of animal pollinated flowers Total Mark Please turn over/.. 7

8 Q7 a) Name the plant structures X, Y and Z shown below, and state which plant part has been modified. 6 X Name Plant part modified Y Name Plant part modified Z Name Plant part modified Please see over/.. 8

9 b) Give ONE NAMED plant example for EACH of the plant structures shown in a). c) State ONE role which is common to all of the plant structures shown in a). Total Mark Please turn over/.. 9

10 Q8 a) State TWO ways by which competition for light affects the growth of plants. b) State what is meant by the term phototropic response. c) Describe the role of auxin in the phototropic response of a plant root. 5 Total Mark Please see over/.. 0

11 Q9 a) List in order the FIVE stages of the plant life cycle. b) State what is meant by the term perennial plant. c) State the difference between woody and herbaceous perennials. d) Complete the table below by giving appropriate NAMED perennial plants. 4 Deciduous woody NAMED perennial plant Deciduous herbaceous Evergreen woody Evergreen herbaceous Total Mark Please turn over/..

12 Q0 a) Name TWO external features at, or close to, the root tip. b) Describe ONE function for EACH of the features named in a). 4 c) State TWO differences between dicotyledonous and monocotyledonous roots. 4 Total Mark *******

13 These questions are the property of the Royal Horticultural Society. They must not be reproduced or sold. The Royal Horticultural Society, Wisley, Woking, Surrey GU 6QB. Charity Registration Number: 879/SC086

14 R0 PLANT CLASSIFICATION, STRUCTURE AND FUNCTION Level Monday 4 June 0 Candidates Registered 405 Total Candidates Passed % Candidates Entered % Passed with Commendation % Candidates Absent % Passed % Candidates Deferred 4.46% Failed % Candidates Withdrawn 8.98% Senior Examiner s Comments: 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. 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. 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. 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. 4

15 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. 0 Candidates should be aware of the reading list of suggested books for the RHS Level 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. Overall Examiners Comments: Q a) State what is meant by EACH of the following terms: i) genus; ii) species. b) State SIX benefits of a universal system for naming plants, rather than using common names. 6 a) The best candidates were able to define the term genus as a sub-group of a plant family made up of a group of species sharing common characteristics. Many candidates were also able to identify a species as a sub-group of a genus, again with common characteristics, stating that individuals of a species are able to interbreed to produce fertile offspring. Marks were also awarded to candidates who stated that species may themselves be further divided into the sub-groups subspecies, varieties and forma. Where candidates provided a binomial plant example marks were only awarded if the generic and specific parts of the name were clearly indicated. b) Candidates who were able to correctly state six distinct benefits of a universal system for naming plants were awarded full marks. Suitable benefits included; Common names may differ for the same plant. The same common name may relate to different plants. A plant may not have a common name. The system uses a common language that is stable and governed by rules. 5

16 This enables standardisation in research and global trade. The plant name can show relatedness between plants and plant groups which is useful in plant breeding and informs their cultural requirements and susceptibility to pests and diseases. The plant name may provide information about the plant itself e.g. colour, habitat, origin etc. The plant name is useful for identifying plants used for different purposes such as medical, culinary, ornamental etc. Marks were not awarded to candidates who stated that the system is Internationally recognised as this is a repeat of the term universal as used in the question. Q a) Name EACH of the features indicated on the diagram below. 5 b) Describe the pathway of water movement through the leaf to the air. 5 a) Most candidates were able to correctly label the cross section of a leaf and did not mistake it for a plant cell. The best candidates named the spongy mesophyll and palisade mesophyll layers fully and used the singular stoma instead of the plural stomata for the leaf pore. The other leaf components required were the epidermis and cuticle. b) Candidates who described the passage of water through the leaf in a logical sequence were awarded high marks. Descriptions included details of the delivery of water to the leaf via the xylem in the veins. Its passage through the leaf from cell to cell by osmosis and also between the cells through the cell walls, evaporation into the intercellular spaces, diffusion through the open stomata and into the surrounding air as water vapour. The best candidates focussed on the movement of water in the leaf and did not give information for which marks could not be awarded e.g. water movement in the rest of the plant, the environmental conditions affecting water flow or the mechanism of stomatal opening and did not confuse diffusion and osmosis. 6

17 Q a) Name the site of aerobic respiration in the cell. b) State the basic word equation for EACH of the following processes: i) aerobic respiration; ii) anaerobic respiration. c) State how the efficiency of respiration is affected by: i) aerobic conditions; ii) anaerobic conditions. a) The majority of candidates identified mitochondria as the site of aerobic respiration in the cell. Candidates who confused the process with photosynthesis could not be awarded any marks. b) Candidates who provided a simple word equation for each process indicating the inputs and outputs correctly gained full marks. i) Aerobic respiration has inputs of oxygen, glucose/ carbohydrate/sugar/starch and outputs of water, carbon dioxide and energy/atp. ii) Anaerobic respiration has an input of glucose and outputs of carbon dioxide, ethanol and energy/atp. c) The best candidates provided statements of how the efficiency of respiration is affected by aerobic and anaerobic respiration without giving unnecessary information of the processes involved or the environmental conditions affecting them e.g. i) Aerobic respiration requires oxygen, is very efficient and the energy is fully released due to the complete breakdown of glucose. ii) Anaerobic respiration does not require any oxygen and is less efficient as the breakdown of glucose is incomplete and gives rise to toxic ethanol. Q4 a) Label EACH of the following cell components on the diagram below: i) cell membrane; ii) nucleus; iii) cytoplasm; iv) vacuole; v) cell wall. 7

18 b) State ONE function for EACH of the cell components listed in a). 5 a) Candidates who were awarded full marks labelled the diagram clearly and correctly by ensuring their arrows were accurately positioned. b) Candidates who gave a clear single function for each cell component gained full marks. Suitable answers included; Cell membrane - contains the cell contents and controls (rather than allows) entry of water and nutrients. Nucleus stores genetic material through which it controls cell processes. Cytoplasm supports cell contents, acts as a medium for reactions to take place and also enables transport of substances within the cell. Vacuole controls cell turgor and stores substances such as waste products and pigments. Cell wall determines the shape of the cell and limits its expansion. It may add strength to cells if it is lignified. Candidates who gave vague functions e.g. the nucleus is the brain of the cell or confused the roles of the cell wall and the cell membrane could not be awarded any marks. Q5 a) Define the term fruit. b) List THREE ways in which fruits can be distributed. c) State what is meant by EACH of the following fruit types: i) dehiscent; ii) indehiscent; iii) succulent. d) Name ONE example for EACH fruit type listed in c): i) dehiscent; ii) indehiscent; iii) succulent. a) Candidates who defined the term fruit as a fertilised or ripened ovary were awarded full marks. Marks were also gained where candidates stated that the role of the fruit is in surrounding and protecting the seeds. b) The majority of candidates were able to list three distribution methods e.g. wind, water, self, animal, including humans (distinguishing between internal and external animal dispersal) and did not confuse fruit with pollen dispersal. Details of the methods of fruit dispersal or plant examples were not required and could not be awarded any marks. c) The best candidates provided clear statements of each of the fruit types and gained full marks. 8

19 i) Dehiscent fruits split open to release their seeds. ii) Indehiscent fruits do not split open. Seeds are released by the fruit rotting etc. iii) Succulent fruits have a fleshy pericarp when mature. d) Marks were awarded to candidates for correctly named botanical fruit types e.g. samara, nut, drupe or for a plant example producing the correct fruit type. i) Dehiscent capsule e.g. Papaver orientale. ii) Indehiscent nut e.g. Quercus robur. iii) Succulent drupe e.g. Prunus persica. Succulent fruits are also indehiscent fruits and so were accepted as examples of indehiscent fruits. Fragaria x ananassa was not accepted as a succulent fruit as it is a pseudocarp bearing achenes which are dry indehiscent fruits. Q6 a) State what is meant by the term pollination. b) State what is meant by EACH of the following terms: i) self-pollination; ii) cross-pollination. c) Describe FIVE characteristics of animal pollinated flowers. 5 a) Candidates who stated that pollination was the transfer of pollen from an anther to a stigma were awarded full marks. b) The best candidates stated that; i) self-pollination is the transfer of pollen within a flower or between flowers on the same plant whereas; ii) cross-pollination is the transfer of pollen between flowers on different plants. c) Most candidates described a good range of characteristics of animal pollinated flowers and gained full marks. Answers included; coloured petals, scent, presence of nectaries and nectar guides, small amount of pollen, large pollen, rough/sticky pollen and opening times for specific animal pollinators. Descriptions of pollen characteristics were also accepted but no marks were awarded when fruit or seed characteristics were described. Q7 a) Name the plant structures X, Y and Z shown below, and state which plant part has been modified. 6 X 9

20 Y Z b) Give ONE NAMED plant example for EACH of the plant structures shown in a). c) State ONE role which is common to all of the plant structures shown in a). a) Candidates who were able to correctly name the plant structures and state the modified plant part were awarded full marks. Suitable answers were; X rhizome which is a modified stem Y bulb which is modified leaves Z corm which is a modified stem/shoot b) The best candidates were able to give the full botanical name for a plant producing each of the structures shown and recognized that some genera e.g. Iris contain examples of more than one structure; in this case both rhizomes and bulbs. Whilst Cyclamen species and Anemone blanda were accepted as corms reclassification has meant that these are now classed as tubers. X rhizome Iris germanica Y bulb Narcissus pseudonarcissus Z corm Crocus tommasinianus c) The majority of candidates correctly identified and stated one role common to all of the plant structures. Suitable answers included; food storage, perennation or asexual/vegetative reproduction. Vegetative propagation could not be awarded full marks as this is a horticultural operation rather than a plant role. Q8 a) State TWO ways by which competition for light affects the growth of plants. b) State what is meant by the term phototropic response. c) Describe the role of auxin in the phototropic response of a plant root. 5 0

21 a) The best candidates were able to state the way in which plant growth is affected by competition for light rather than the role of light in plant growth or plant adaptations e.g. climbing and avoided vague terms i.e. poor growth. Suitable answers included; stem elongation, etiolation, reduction in leaf number and size, juvenile growth, reduction in fruiting and flowering and chlorosis due to a lack of chlorophyll. b) Candidates who stated that phototropism is a growth movement in response to light and can be towards (positive) or away from (negative) light rather than simply leaning or bending towards the light were awarded full marks. Candidates who confused phototropism with geotropism or photoperiodism could not be awarded any marks. c) Marks were awarded to those candidates who described how auxin accumulates on the shaded side of roots where it reduces cell expansion (unlike in shoots) thus causing differential growth across the root resulting in it bending away from the light. This is negative phototropism e.g. adventitious roots of Hedera helix which grow away from the light into the stem of its host. Candidates who described phototropism in stems did not gain any marks. Q9 a) List in order the FIVE stages of the plant life cycle. b) State what is meant by the term perennial plant. c) State the difference between woody and herbaceous perennials. d) Complete the table below by giving appropriate NAMED perennial plants. 4 Deciduous woody NAMED perennial plant Deciduous herbaceous Evergreen woody Evergreen herbaceous a) Full marks were awarded to those candidates who listed the five stages of the plant life cycle in the correct order i.e. seed, juvenile, adult, senescence and death. b) Most candidates correctly stated that a perennial plant is one whose life cycle lasts more than two years/seasons rather than for two years or more or over two years which could refer to a biennial. Candidates who stated that a perennial plant is one that lasts for many years

22 were not awarded any marks as it was not precise enough. c) The best candidates stated that woody perennials develop a permanent aboveground framework through secondary thickening, whereas herbaceous perennials do not, causing herbaceous perennials to often die down in the winter. d) It was important for candidates to select plants that were unambiguous examples of the categories required to complete the question successfully e.g. Vinca major is sometimes sold as an herbaceous perennial although it is a woody shrub. Stachys byzantina may or may not be classed as an evergreen herbaceous perennial. Where candidates only provided a genus, marks could only be awarded if all the species of the genus are in the same category e.g. not all species of Euphorbia are evergreen. Suitable examples provided for each category included; Cornus alba and Fagus sylvatica for deciduous woody, Echinacea purpurea and Knautia macedonica for deciduous herbaceous, Skimmia japonica and Ilex aquifolium for evergreen woody and Bergenia cordifolia and Ajuga reptans for evergreen herbaceous. Q0 a) Name TWO external features at, or close to, the root tip. b) Describe ONE function for EACH of the features named in a). 4 c) State TWO differences between dicotyledonous and monocotyledonous roots. 4 a) The majority of candidates were able to name two external features close to the root tip. Suitable answers included root cap and root hair. b) The best candidates described the function of their chosen features fully e.g. the root cap protects the root from damage by soil particles as it grows through the soil by exuding mucilage and replacing lost cells and the root hairs enlarge the surface area for water and nutrient uptake. c) Candidates who correctly identified a clear difference between monocotyledonous and dicotyledonous roots and compared them rather than just describing the feature for one of the root types were awarded full marks. Suitable examples of the differences included; monocotyledons have shallow, fibrous, adventitious root systems without secondary thickening and can have a stele with multiple arms whereas dicotyledonous roots can have a deep, dominant tap or primary root with laterals (but may also have adventitious fibrous roots), they can undergo secondary thickening and have steles with few arms. Marks could not be awarded where stem features were described. ********

23 These questions are the property of the Royal Horticultural Society. They must not be reproduced or sold. The Royal Horticultural Society, Wisley, Woking, Surrey GU 6QB. Charity Registration Number: 879/SC086