PLEASE NOTE THIS IS 1 QUESTION THAT HAS SUBQUESTION AND WILL NEED TO BE ANSWERED AT ONCE. Separating these question would result in confusion.
14. Under the correct conditions, new roots grow from the cut end of a plant stem. A scientist investigated the effect of substance X on the growth of new roots. She used a ringing experiment to investigate the movement of substance X in stems taken from lemon plants. She cut out a length of stem from each plant. She then put a small block of agar on the top of each length of stem. Some agar blocks (Treatment E, F and G) contained substance X. Treatment was a control. The experimental design is illustrated by the diagram below. D E F Block G of agar Cooled to 4 C All phloem removed No substance X in agar, middle section of stem intact Substance X in agar, middle section of stem intact Substance X in agar, middle section of stem ringed Substance X in agar middle section of stem intact and cooled to 4 "C She grew the lengths of stem in the same environmental conditions for 6 weeks, and then found the number of roots per length of stem. Roots grew at the other end of the stem from where the agar blocks were placed. The table below shows the results. Treatment Mean number of roots per length of stem 5 11 F 4 G 3 E a. Explain how the results from Treatment Dare used by the scientist. (2 marks) b. What can you conclude by comparing results from Treatments D and E? (2 marks) C Given the results from Treatment F, what is substance X likely to be? (2 marks) d. What does the result from Treatment G suggest? (2 marks) e. What do the results of this experiment indicate about requirements for root growth? (2 marks) 14. Under the correct conditions, new roots grow from the cut end of a plant stem. A scientist investigated the effect of substance X on the growth of new roots. She used a ringing experiment to investigate the movement of substance X in stems taken from lemon plants. She cut out a length of stem from each plant. She then put a small block of agar on the top of each length of stem. Some agar blocks (Treatment E, F and G) contained substance X. Treatment was a control. The experimental design is illustrated by the diagram below. D E F Block G of agar Cooled to 4 C All phloem removed No substance X in agar, middle section of stem intact Substance X in agar, middle section of stem intact Substance X in agar, middle section of stem ringed Substance X in agar middle section of stem intact and cooled to 4 "C She grew the lengths of stem in the same environmental conditions for 6 weeks, and then found the number of roots per length of stem. Roots grew at the other end of the stem from where the agar blocks were placed. The table below shows the results. Treatment Mean number of roots per length of stem 5 11 F 4 G 3 E a. Explain how the results from Treatment Dare used by the scientist. (2 marks) b. What can you conclude by comparing results from Treatments D and E? (2 marks) C Given the results from Treatment F, what is substance X likely to be? (2 marks) d. What does the result from Treatment G suggest? (2 marks) e. What do the results of this experiment indicate about requirements for root growth? (2 marks)
