INCLUDING EXAMINER COMMENTS R3101 PLANT TAXONOMY, STRUCTURE & FUNCTION Level 3 Wednesday 24 June 2015 09:30 – 11:10 Written Examination Candidate Number:…………………………………………………………………. Candidate Name:……………………………………………………………………. Centre Number/Name:……………………………………………………………… IMPORTANT – Please read carefully before commencing: i) The duration of this paper is 100 minutes; ii) ALL questions should be attempted; iii) EACH question carries 10 marks; iv) Write your answers legibly in the spaces 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 may be used for drawing purposes 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 H/505/2966 Please turn over/….. ANSWER ALL QUESTIONS MARKS Q1 a) Differentiate between family and genus giving a NAMED example for EACH. 4 ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ……………………………………………………………………………………….... ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… …………………………………………………………………………………………. Please see over/….. 2 MARKS b) State the meaning of the term intergeneric hybrid, giving a NAMED plant example. 2 ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ……………………………………………………………………………………….... c) Explain, using TWO NAMED plant examples how specific epithets can indicate the geographical origin of plants. 4 ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… Total Mark ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… Please turn over/….. 3 MARKS Q2 a) Describe the following types of inflorescence, giving a NAMED example for EACH: i) ii) iii) umbel; corymb; cyme. 2 2 2 ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… Please see over/….. 4 MARKS ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… b) Describe the structure of a capitulum of a NAMED plant indicating how it is adapted for pollination. 4 ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… Total Mark ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… Please turn over/….. 5 MARKS Q3 a) Describe parenchyma under EACH of the following: i) ii) 2 4 structure of the cells; functions of the tissue. ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… Please see over/….. 6 MARKS b) State the function(s) of EACH of the following: i) ii) iii) collenchyma; sclereids; epidermis. 1 1 2 ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… Total Mark ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… Please turn over/….. 7 MARKS Q4 a) State, in relation to flowering, what is meant by the terms: i) ii) vernalisation; photoperiodism. 2 2 ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… b) Define the following terms giving a NAMED plant example for EACH: i) ii) iii) 2 2 2 short day plant; long day plant; day neutral plant. ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… Please see over/….. 8 MARKS ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… Total Mark ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… Please turn over/….. 9 MARKS Q5 a) Differentiate between a true fruit and a false fruit. 2 ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… b) i) Describe the structure of a NAMED succulent/fleshy true fruit. 3 ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ii) 1 NAME ONE plant example with this type of fruit. ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… Please see over/….. 10 MARKS c) Describe the following fruits giving a NAMED plant example for EACH: i) ii) legume; achene. 2 2 ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… Total Mark ……………………………………………………………………………………….... ………………………………………………………………………………………… ……………………………………………………………………………………….... Please turn over/….. 11 MARKS Q6 Describe, using a NAMED plant example in EACH case, how their flowers are adapted for pollination by: i) ii) 5 5 flies; birds. …………………………………………………………………………………………. ……………………………………………………………………………………….... …………………………………………………………………………………………. …………………………………………………………………………………………. …………………………………………………………………………………………. ……………………………………………………………………………………….... …………………………………………………………………………………………. …………………………………………………………………………………………. …………………………………………………………………………………………. ……………………………………………………………………………………….... ……………………………………………………………………………………….... ……………………………………………………………………………………….... …………………………………………………………………………………………. ……………………………………………………………………………………….... …………………………………………………………………………………………. …………………………………………………………………………………………. …………………………………………………………………………………………. ……………………………………………………………………………………….... …………………………………………………………………………………………. …………………………………………………………………………………………. …………………………………………………………………………………………. ……………………………………………………………………………………….... ……………………………………………………………………………………….... ……………………………………………………………………………………….... ……………………………………………………………………………………….... ……………………………………………………………………………………….... ……………………………………………………………………………………….... …………………………………………………………………………………………. …………………………………………………………………………………………. Please see over/….. 12 MARKS ………………………………………………………………………………………… ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… Total Mark ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… Please turn over/….. 13 MARKS Q7 a) Explain how increasing temperature influences the rate of photosynthesis in plants. 6 ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… Please see over/….. 14 MARKS ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… b) List FOUR distinct methods by which temperature can be manipulated in glasshouse production to maximize photosynthesis. 4 ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… Total Mark ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… Please turn over/….. 15 MARKS Q8 a) Describe the structure of a mitochondrion. 2 ………………………………………………………………………………………… ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… b) Describe the processes that occur in mitochondria during aerobic respiration. 4 ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… Please see over/….. 16 MARKS c) State the difference between a climacteric fruit AND a non-climacteric fruit, giving a NAMED example for EACH. 4 ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ……………………………………………………………………………………….... 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Please turn over/….. 17 MARKS Q9 a) Describe how outdoor planting conditions affect the rate of transpiration. 6 ………………………………………………………………………………………… ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… Please see over/….. 18 MARKS b) Explain how the rate of transpiration affects plant growth. 4 ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… Total Mark ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… Please turn over/….. 19 MARKS Q10 a) i) Describe the mechanism of gravitropism (geotropism) in the root. 4 ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ii) Explain the significance of gravitropism for growth of the root and shoot in a germinating seedling. 2 ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… Please see over/….. 20 MARKS ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… b) i) Define the term thigmotropism. 1 ………………………………………………………………………………………… ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… ii) Explain the significance of thigmotropism for the growth of a NAMED plant. 3 ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ………………………………………………………………………………………… ……………………………………………………………………………………….... ………………………………………………………………………………………… ******* 21 Total Mark DO NOT USE THIS PAGE 22 DO NOT USE THIS PAGE 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 GU23 6QB. Charity Registration Number: 222879/SC038262 24 R3101 PLANT TAXONOMY, STRUCTURE & FUNCTION Wednesday 24 June 2015 Level 3 Candidates Registered Candidates Entered Candidates Absent/Withdrawn 45 40 5 88.89% 11.11% Total Candidates Passed Passed with Commendation Passed Failed 24 7 17 16 60% 17.5% 42.5% 40% General comments On the whole this paper was well answered with the majority of candidates attempting and completing all the questions. The following guidelines should be of help to future candidates. Where named plant examples are asked for, full botanical names (genus and species) are required to achieve full marks. Common names will not be given a mark. Use the command statements e.g. list or name (single words only), state (a few sentences), describe or explain (a fuller answer) together with the mark allocation, to judge the depth of the answer. Half marks are often allocated where the basic information given is correct but needs further qualification to gain the full mark. Where a number of answers are specified in the question, the examiner will not select correct answers from a list e.g. if the question states ‘State’ TWO plant names’, only the first two names given will be marked. Labels on diagrams should be correctly positioned to avoid ambiguity and diagrams should be clearly drawn and annotated. No marks will be awarded for artistic merit. Candidates should use unambiguous plant examples as reference sources from, for example, the RHS Find a Plant Service available on the RHS Website. 25 Q1 a) Differentiate between family and genus giving a NAMED example for EACH. b) State the meaning of the term intergeneric hybrid, giving a NAMED plant example. c) Explain, using TWO NAMED plant examples how specific epithets can indicate the geographical origin of plants. Full marks were awarded for defining family and genus in terms of their position in the taxonomic hierarchy, for example, family is the rank below order or above genus. Alternatively, marks were awarded for stating that a family comprises a group of closely related genera, similarly a genus comprises a group of closely related species. Simply stating that either taxon consists of a group of closely related plants or plants with similar characteristics was not precise enough to be awarded full marks as this could apply to any taxon. Whilst similarities in flower structure occur between species which make up a genus, stating that a genus is a group of plants with identical sexual organs is incorrect and is not a definition. Candidates should ensure that family names have the correct ending –aceae. Where candidates gave a binomial name as an example of a genus, marks were awarded only if the generic epithet was indicated. Most candidates successfully defined an intergeneric hybrid as a cross between two plants or species from different genera, the commonest example being xCuprocyparis leylandii. Many correct examples of specific epithets indicating geographical origin were given including lusitanica (from Portugal), australis (southern) and sinensis (from China). Q2 a) Describe the following types of inflorescence, giving a NAMED example for EACH: i) ii) iii) umbel; corymb; cyme. b) Describe the structure of a capitulum of a NAMED plant indicating how it is adapted for pollination. Most candidates correctly described an umbel, e.g. Allium giganteum, which has pedicels arising from the same point on the peduncle and a corymb e.g. Sambucus nigra which is a flat topped inflorescence with pedicels of different lengths arising from different points on the peduncle. An Achillea species was given by many as an example of a corymb and this was accepted because the capitula are arranged in a corymbose fashion in the inflorescence. Clear and accurate diagrams were also accepted. A cyme e.g. Myosotis sylvatica, was less well known and the key feature that this is a determinate inflorescence with the oldest flowers at the apex was not well described. Where diagrams were used to illustrate a cyme it was essential to indicate the order of flowering. 26 Almost any member of the Asteraceae could be used as an example of a capitulum e.g. Bellis perennis. Detailed descriptions of specific structural features gained full marks, for example, closely packed ray and disc florets which are attached to a flat topped receptacle. These may be sterile or fertile and are sessile. The calyx becomes a pappus. The whole inflorescence is supported by overlapping bracts forming an involucre. Again, adaptations for pollination needed to be specific with better candidates describing how the flat capitulum enables insects to gather nectar and pollen efficiently with minimal energy expenditure because they can walk from floret to floret and these are in close proximity. Although diagrams were accepted it was difficult to gain full marks here without some description either on the diagram or in the text. Q3 a) Describe parenchyma under EACH of the following: i) ii) structure of the cells; functions of the tissue. b) State the function(s) of EACH of the following: i) ii) iii) collenchyma; sclereids; epidermis. The structure of parenchyma cells in part a) was generally well described with candidates noting that these were living cells, often undifferentiated with thin cellulose walls which are unlignified and permeable. They contain organelles such as mitochondria, a nucleus and a vacuole and characteristically have air spaces between the cells. As well as acting as ‘packing’ or support tissue, other functions were accepted including starch or water storage, photosynthesis in chlorenchyma, buoyancy and oxygen uptake in aerenchyma and the potential ability to divide and differentiate into other cells, for example in callus production. Where diagrams were drawn these often showed a generalised cell which could not be credited unless the specific features of parenchyma were indicated or described. In part b), candidates who described functions of the tissues rather than their structures were credited. Thus collenchyma’s function is to support or strengthen, particularly in leaves, stems and petioles where flexibility is required. Sclereids also have a strengthening and supportive role and provide protection in the endocarp of fruits e.g. stone cells. Some candidates confused these with tracheids. For epidermis, several functions could be given including protection from pests, diseases and damage, control of water release and gaseous exchange through stomata together with any specialised functions such as prickles for defence or trichomes for reducing water loss. The term ‘providing structure’ was not credited for any of these cell and tissue types. 27 Q4 a) State, in relation to flowering, what is meant by the terms: i) ii) vernalisation; photoperiodism. b) Define the following terms giving a NAMED plant example for EACH: i) ii) iii) short day plant; long day plant; day neutral plant. In part a), the majority of candidates correctly stated that vernalisation is the requirement for a period of cold to initiate or promote flowering. Mention of day degrees or details of specific temperatures and treatment times were also credited. Stating the meaning of photoperiodism was less easy. Full marks were given for understanding that this is a plant’s response to changes in the length of daylight (or darkness) in a 24 hour period, rather than the amount of light, which controls the switch between vegetative and flowering growth. The definitions in part b) had to include a reference to the idea of plants having a specific daylength or critical daylength requirement. Therefore, short day plants flower if the daylength is less than their critical daylength, whilst in long day plants the daylength must be greater than the plant’s critical daylength for the plant to flower. Simply stating that flowering in short day plants takes place in ‘short days’ or for long day plants in ‘long days’ was not accepted without some explanation of what these terms mean. Flowering in day neutral plants is unaffected by daylength. Plant examples chosen should be easy to verify, for example, Chrysanthemum morifolium (SDP), Latuca sativa (LDP) and Taraxacum officinale (DNP). Good examples can be found amongst plants used in bedding, pot plants and cut flower production but are less easy to find in herbaceous and woody perennials. Q5 a) Differentiate between a true fruit and a false fruit. b) i) ii) Describe the structure of a NAMED succulent/fleshy true fruit. NAME ONE plant example with this type of fruit. c) Describe the following fruits giving a NAMED plant example for EACH: i) ii) legume; achene. Most candidates correctly described true fruits as originating from the ovary compared with false fruits in which other flower tissues, such as the receptacle, are included. Many forgot to mention that false fruits still include the ovary and a number thought that fruits develop within the ovary. In describing the structure of a named succulent true fruit, several candidates chose false fruits such as a pome so could not be credited. Suitable fruits named were berries and drupes. Drupes have a thin exocarp, a fleshy mesocarp and a hard stony endocarp, which is fused to the surface of the single seed e.g. in Prunus avium, and are formed from one carpel, whilst berries have a similar exocarp and mesocarp but have many seeds embedded in a fleshy endocarp e.g. in Vitis vinifera, and are formed from two or more carpels. 28 In part b), most candidates knew of a suitable plant example for a legume e.g. Pisum sativum and were able to state that it was a dry, dehiscent fruit which splits along two sides as fibres in the pericarp shorten and twist on drying. Candidates were less familiar with achenes, which were often confused with nuts. These are dry indehiscent fruits containing one seed with a separate pericarp and testa. Both legumes and achenes derive from one carpel. A good example for an achene would be Helianthus annuus. Several described strawberries as achenes themselves rather than the individual achenes which are embedded in the surface of the false fruit. In both parts a) and b) detailed descriptions of each fruit gained full marks. Q6 Describe, using a NAMED plant example in EACH case, how their flowers are adapted for pollination by: i) ii) flies; birds. Most candidates were able to name a specific plant pollinated by flies and birds. For fly pollinated flowers, better candidates gave a detailed description of their chosen flower and appreciated that the type of pollinating fly is influenced by the structure of the flower. So for carrion flies, plant examples included Arum maculatum and Stapelia gigantea and these have somewhat different flower structures and mechanisms. For hoverflies, bee flies etc. suitable plant examples included Angelica sylvestris and Hedera helix. Detailed descriptions of fly trapping mechanisms, flower size and position, specific colours, presence or absence and type of scent and opening time all gained marks as did mention of the presence or absence of nectar and inflorescence structure. Full marks were awarded where the flower structure was linked to the behaviour of the fly, for example an odour of rotting flesh attracting carrion flies which feed on dead animal matter or a flat flower inflorescence enables hoverflies to walk from flower to flower with the least energy expenditure. Similarly for bird pollination, the majority chose flowers pollinated by humming birds e.g. Fuchsia magellanica whilst others described flowers on which birds perch to feed e.g. Strelizia reginae. In each case, the flower structure will differ according to the way in which the birds feed. Again, marks were awarded for a detailed description which linked specific flower structure to pollination method such as the position of the stigma and stamens, colour, type and amount of nectar and scent. For example, these flowers have little scent because a sense of smell is not highly developed in birds but they are brightly coloured, often red, to stand out from foliage and attract birds from far off. Q7 a) Explain how increasing temperature influences the rate of photosynthesis in plants. b) List FOUR distinct methods by which temperature can be manipulated in glasshouse production to maximize photosynthesis. 29 In part a), the best approach to this question was to start with a clear statement that increasing temperature initially increases the rate of photosynthesis. This could then be followed by an explanation of the reasons. So, as temperature increases, the activity of the enzymes involved in the light independent reactions of photosynthesis is increased as is the rate of diffusion of carbon dioxide into the leaf. Next, candidates should state that above an optimum temperature, the rate of photosynthesis declines as temperature increases. This is due to high temperatures causing a reduction in enzyme activity due to loss of enzyme structure. Many stated that high transpiration rates at high temperatures would reduce water availability for photosynthesis but this is not the case since there is always sufficient water in cells for use in photosynthesis. However, high transpiration rates will indirectly reduce the rate of photosynthesis because stomatal closure to reduce water loss leads to a decline in carbon dioxide uptake and wilting reduces the leaf surface area exposed to light. The reduction in photosynthetic output in C3 plants at high temperatures due to photorespiration was credited as was the increased temperature optima in C4 species. Mention of the Law of Limiting Factors was also rewarded. In part b), full marks were given for stating a method to control temperature in glasshouses with examples of how this is done e.g. heating using hot water pipes or hot air convectors to increase temperature. Methods used to reduce temperature could include ventilation, both passive or fan assisted; evaporative cooling and increasing humidity through damping down or use of wet pads and fans; or shading using screens or paint on materials. Q8 a) Describe the structure of a mitochondrion. b) Describe the processes that occur in mitochondria during aerobic respiration. c) State the difference between a climacteric fruit AND a non-climacteric fruit, giving a NAMED example for EACH. Most candidates successfully described the structure of a mitochondrion using a diagram indicating the key features: cristae, matrix and double membrane. The presence of DNA and ribosomes was also mentioned by some. In part b), many candidates only gave the overall equation for aerobic respiration and could not gain full marks unless they described the processes involved. In the matrix, pyruvate used in the Krebs Cycle to generate ATP where carbon dioxide and oxygen diffuses across to the cristae. Here, electrons which are passed along an electron transport chain and hydrogen provided by hydrogen carriers (reduced co-enzymes) combine with oxygen to produce water. Overall 38 molecules of ATP are produced from 1 molecule of glucose. Since splitting of glucose (glycolysis) takes place in the cell cytoplasm no mark was awarded for this. In part c), few candidates understood the meaning of the terms climacteric and non-climacteric fruit and hardly any gave full botanical names of examples. Although many correctly mentioned the peak in ethylene levels or sudden ripening which are characteristic of climacteric fruit, it is the respiratory pattern which is the key. 30 Simply stated, climacteric fruit such as Pyrus communis (pear) show a burst of respiration on ripening whereas non-climacteric fruits such as Fragaria x ananassa (strawberry) do not. Some gave plants with dry fruits as examples of non-climacteric behaviour but the terms are generally used to describe succulent fruit. Q9 a) Describe how outdoor planting conditions affect the rate of transpiration. b) Explain how the rate of transpiration affects plant growth. To answer the first part of this question, candidates needed to consider the range of environmental conditions which affect the rate of transpiration in an outdoor setting e.g. air temperature, relative humidity, windspeed, light levels, shade and soil water availability. No marks were awarded where a factor was given but its effect on the rate was not stated. For example ‘air temperature affects the rate of transpiration’ was not sufficient; whereas’ if the air temperature increases the rate of transpiration increases up to a point then reduces’, was credited. Following on from this, the reason for the change in rate needed to be explored e.g. increasing temperature increases the rate of diffusion of water vapour from the leaf but at high temperatures the stomata close, so transpiration ceases. Similarly, better candidates stated that high windspeeds will reduce the boundary layer width around the leaf so increasing the diffusion gradient and the rate of water vapour loss, or high humidity in the surrounding air will reduce transpiration rates because the difference in water vapour concentration inside and outside the leaf is reduced. Low soil water availability will reduce transpiration rates because of stomatal closure to conserve moisture, which is mediated by abscisic acid. Discussion of the effects of plant spacing on transpiration rates should be linked to its effect on the environmental factors above. In the second part of the question, very few candidates were able to link transpiration to growth. Firstly transpiration is required to supply minerals for processes involved in growth e.g. photosynthesis, cell wall manufacture. Secondly, sufficient turgor is necessary for maximum cell expansion and if transpiration rates are too high turgor will be reduced. Thirdly at very high transpiration rates stomata will close, leaves will wilt, leaf area will be reduced or leaves shed so net photosynthesis will be reduced along with growth. Q10 a) b) i) Describe the mechanism of gravitropism (geotropism) in the root. ii) Explain the significance of gravitropism for growth of the root and shoot in a germinating seedling. i) Define the term thigmotropism. ii) Explain the significance of thigmotropism for the growth of a NAMED plant. 31 Candidates who defined the term gravitropism in relation to the root (downwards growth in response to gravity) and then went on to give an explanation of one or more mechanisms, scored highly. Mechanisms describing the involvement of statoliths or changes in cell turgor/hydrostatic pressure or calcium concentrations were all credited as was the involvement of auxin which accumulates on the downward side of the root where it inhibits cell expansion leading to downwards curvature. Whilst candidates appreciated that roots grow down and shoots grow up, the reasons why they grow in these directions e.g. roots need to locate water and mineral nutrients or shoots need to reach the light for photosynthesis were not always given. Well annotated diagrams were accepted. Thigmotropism was familiar to almost all and was well defined being a tropic response to contact with a solid object. Plants with twining stems, e.g. Wisteria sinensis or tendrils e.g. Pisum sativum were suitable examples. However marks were often lost by candidates who described the mechanism of thigmotropism rather than explaining why this is important to the plant. It enables them to reach the light for photosynthesis, raise flowers above other plants for better pollination or avoid herbivores, giving them a competitive advantage. ©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. 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