19:43 YET.. 17% ← NW NSC LFSC P1...NG SEPT 2024.pdf - Read-only Ky Copyright reserved Life Sciences/P1 12 NSC Please turn over NW/September 2024 QUESTION 3 3.1 The Grade 12 learners investigated the effect of abscisic acid on plant dormancy. The procedure was as follows: . A greenhouse was set up with a constant temperature of 28 °C and a 30% humidity level. 16 pear trees of similar age and size were placed in the greenhouse. The trees were divided into group A and group B with 8 trees in each group. In group A, the 8 trees were treated with abscisic acid for 5 days. In group B, the 8 trees were treated with water only for 5 days. The shedding of leaves by the plants was observed. The learners recorded their observations for seven days. The diagram below shows the observation made at the end of the seven days. The diagram does NOT represent all the trees that were investigated nor the actual size of the trees. Group A Group B 3.1.1 State the aim of the investigation. 3.1.2 Identify the following: (a) Independent variable (b) Dependent variable (c) ONE controlled variable 3.1.3 What is meant by abscission? 3.1.4 State TWO other functions of abscisic acid in plants. Copyright reserved Life Sciences/P1 13 NSC (1) (1) (1) (1) (1) (2) Please turn over NW/September 2024 3.1.5 State TWO ways in which the learners could have made their results more reliable. 3.1.6 As a follow up the leamers changed the temperature of the greenhouse to 40 °C. Explain the effect of the change in temperature on the results of the investigation. (2) (11)