Transpiration rate (g H?O m?²hr?¹) 10 8 6 4 2 0 0 0.5 1 3 6 24 48 120 Treatment time (hr) Figure 18. Time course of transpiration rate in the leaves of pumpkin-grafted cucumber (C/P) and self-grafted cucumber (C/C) plants after 75 mM NaCl treatment. Data are presented as the mean of six biological replicates (± SE), points with an asterisk indicate a significant difference from the untreated control (P ? 0.05) at the same sampling time according to t-test. QUESTION 18: In addition to photosynthetic rate, transpiration rates declined in response to the salt treatment. Which grafting combination showed the greatest change in transpiration rate during the first hour of the salt treatment? (2 POINTS) A. Pumpkin-grafted cucumber (C/P) B. Self-grafted cucumber (C/C) QUESTION 19: In general, rapid closure of stomata prevent decreases/increases in pressure potential in the hydration shell of the leaf mesophyll. This is because closing stomata causes less water to evaporate from the hydration shell, which prevents radii of menisci in the hydration shell from enlarging/shrinking. (3 POINTS) UNDERLINED TERMS IN THIS QUESTION ARE PRESENTED IN DROPDOWN MENUS. PLEASE NOTE THAT CANVAS RANDOMIZES SEQUENCES OF OPTIONS IN INDIVIDUAL DROPDOWN MENUS
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We are asked if transpiration rates declined in response to the salt treatment during the first hour. To answer this question, we need to look at Figure 18, which shows the time course of transpiration rate. We can compare the transpiration rates of the treated Show more…
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