2 marks 6 11 Do not write outside the box GJun14BL3HP Turn over 11 5 The leaves

2 marks 6 11 do not write outside the box gjun14bl3hp

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[2 marks] ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ ____ 6
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11 Do not write outside the box G/Jun14/BL3HP Turn over (11) 5 The leaves of most plants have stomata. 5 (a) (i) Name the cells which control the size of the stomata. [1 mark] ............................................................................................................................................ 5 (a) (ii) Give one function of stomata. [1 mark] ............................................................................................................................................ ............................................................................................................................................ 5 (b) Figure 5 shows part of the surface of a leaf. Figure 5 0.1 mm 0.1 mm The length and width of this piece of leaf surface are both 0.1 mm. 5 (b) (i) Calculate the number of stomata per mm 2 of this leaf surface. [2 marks] ............................................................................................................................................ ............................................................................................................................................ .................................................. per mm 2
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12 Do not write outside the box G/Jun14/BL3HP (12) 5 (b) (ii) A different plant species has 400 stomata per mm 2 of leaf surface. Having a large number of stomata per mm 2 of leaf surface can be a disadvantage to a plant. Give one disadvantage. [1 mark] ............................................................................................................................................ ............................................................................................................................................ 5 (c) A student investigated the loss of water from plant leaves. The student did the following: Step 1: took ten leaves from a plant Step 2: weighed all ten leaves Step 3: hung the leaves up in a classroom for 4 days Step 4: weighed all ten leaves again Step 5: calculated the mass of water lost by the leaves Step 6: repeated steps 1 to 5 with grease spread on the upper surfaces of the leaves Step 7: repeated steps 1 to 5 with grease spread on both the upper and lower surfaces of the leaves. All the leaves were taken from the same type of plant. Table 2 shows the student’s results. Table 2 Treatment of leaves Mass of water the leaves lost in g No grease was used on the leaves 0.98 Grease on upper surfaces of the leaves 0.86 Grease on upper and lower surfaces of the leaves 0.01
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13 Do not write outside the box G/Jun14/BL3HP (13) 5 (c) (i) What mass of water was lost in 4 days through the upper surfaces of the leaves? [1 mark] ............................................................................................................................................ ............................................................................................................................................ Mass = .................... g 5 (c) (ii) Very little water was lost when the lower surfaces of the leaves were covered in grease. Explain why. [3 marks] ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ ____ 9 Turn over for the next question Turn over
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14 Do not write outside the box G/Jun14/BL3HP (14) 6 Figure 6 shows the core body temperature and the skin surface temperature of a cyclist before, during and after a race. Figure 6 Temperature in °C Key Core body temperature Skin surface temperature 10.00 10.30 11.00 09.00 27 31 35 39 29 33 37 41 09.30 09.45 10.15 10.45 09.15 Start of race Time of day in hours and minutes 6 (a) (i) When the cyclist finished the race, his core body temperature started to decrease. How long did the race last? [1 mark] ............................................................................................................................................ 6 (a) (ii) Describe and explain the different patterns shown in the core body temperature and skin surface temperature between 09.15 and 10.15. [6 marks] ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................
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15 Do not write outside the box G/Jun14/BL3HP Turn over (15) ............................................................................................................................................
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