CHIJ St Nicholas 2016 Bio Prelim P1 MS

1 G CHIJ St. Nicholas Girls’ School 2016 Secondary 4 (O Level) Biology Prelim Marking Scheme and Markers’ Report General Comments Generally, candidates who attempted the Either question performed better with a handful of candidates scoring close to full marks. Most students did not perform well for this exams. Answers generally lacked details and precision. Paper 1 (40 marks) Question 1 2 3 4 5 6 7 8 9 1 0 Answer D A B D C C B A B B Question 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 Answer B A A A D D C B B A Question 2 1 2 2 2 3 2 4 2 5 2 6 2 7 2 8 2 9 3 0 Answer B D A C A D B C B C Question 3 1 3 2 3 3 3 4 3 5 3 6 3 7 3 8 3 9 4 0 Answer A / C A D B D B A B D A Comments on MCQ Question 4 77% of candidates got this question incorrect. Most candidates chose distractor A instead of answer D. Candidates showed understanding that the vacuole will decrease in size due to the movement of water out of the cell by osmosis. However, they were careless and failed to identify the slight change in shape in the cell wall due to the shrinkage of the cytoplasm. 165 trendylinetanding that the vacuole will decrease in size due to the m ess and failed to identify the slight change in shape in the cell wall due to the s

2 Question 5 57% of candidates got this question incorrect. Most candidates chose distractor A instead of answer C. Candidates failed to recognise water as the main constituent of the amniotic fluid, which provides protection to a growing foetus. Question 11 Many candidates chose options A and C instead of answer B. From the graph, the % of stomata that are open varies with changes in light intensity throughout 24 hours in a day. No information on temperature is given. With the graph being higher during daytime and higher % of stomata are open, it can be deduced that transpiration occurs at a higher rate. It also cannot be deduced from the graph that photosynthesis only occurs in light because in darkness, there are still gases present within the intercellular air spaces. Question 12 44% of candidates chose distractor D instead of answer A. While candidates understand that light intensity was the limiting factor at the start of the graph, they failed to understand that for graph of Y, they will have to compare it with the graph below and the difference in carbon dioxide concentration indicates that it is the change in that condition that results in a higher rate in graph of Y. Question 14 55% of candidates chose distractor C instead of answer A. 166 trendylinecompare it with the graph below and the difference in ca n that results in a higher rate in graph of Y. stractor C instead of answer A.

3 Candidates wrongly identified the cells as the sides as sieve tube cells and wrongly deduced the vessel to be the phloem. Candidates should be able to recognise the shape of companion cells. They are slightly flattened and tapered at ends. Question 15 65% of candidates go