Today, I will be analysing a question from the topic of Web of Life<\/strong><\/a> in the 2018 Nanyang Primary School (NYPS) P6 Prelim<\/strong>\u00a0Examination Paper<\/strong>.<\/p>\n Web of Life<\/strong><\/a> is an interesting topic about how different organisms in the food web depend on each other directly\/ indirectly for food. In this topic, we will be able to observe how a change in the population of just one organism can greatly affect the population of all the other organisms in the food web!<\/p>\n As usual, I will first share with you the topic weightage before discussing the question.<\/p>\n\n Here is the list of topics that are commonly taught in the P6 curriculum and the number of questions tested for each topic:<\/p>\n Here are the list of topics that are commonly taught in the P5 curriculum and the number of questions tested for each topic:<\/p>\n Here are the topics that are commonly taught in the P3 and P4 curriculum and the number of questions tested for each topic:<\/p>\n The table below is a summary of the topical weightage in this paper:<\/p>\n As seen from the topic weightage above, every P6 topic was tested in this paper.<\/p>\n Hence, if your child would like more question exposure on these topics, the 2018 Nanyang Primary School (NYPS) P6 Prelim<\/strong>\u00a0Examination Paper<\/strong> will be ideal to practise!<\/p>\n If your child wants to work on questions on Diversity, Materials, Animal Life Cycle, Matter and Cells, this paper is not ideal.<\/p>\n Since Web of Life<\/a> is an interesting topic, I would like to discuss Q5, a challenging question from this topic in the examination paper.<\/p>\n Source: Nanyang Primary School (NYPS) \u2013 2018 P6 Prelim Examination Paper [Q5]<\/em><\/p>\n When a food web is given in a Web of Life<\/a> question, there are 2 tips that I share with my students:<\/p>\n The food producer(s) does\/ do not feed on anything and is\/ are only eaten by other organisms.<\/p>\n Food producer(s) only has\/ have arrows pointing away<\/u><\/strong> from itself\/ themselves in the food web.<\/p>\n The \u201cKing(s)\u201d feeds\/ feed on other animals but no other animals feed on it\/ them.<\/p>\n \u201cKing(s)\u201d only has\/ have arrows pointing towards<\/u><\/strong> it\/ them.<\/p>\n Since organisms Q and T<\/u> <\/strong>only have arrows pointing away<\/u><\/strong> from themselves as shown below, we can identify Q and T as the food producers and label “FP” beside Q and T on the food web.<\/p>\n Since organism P<\/u> <\/strong>only has arrows pointing towards<\/u><\/strong> it as shown below, we can identify P as the \u201cKing\u201d and label “King” on top of P on the food web.<\/p>\n Both the “FP” and “King” are now labelled on the food web as shown below:<\/p>\n After identifying the food producers and the \u201cKing\u201d, we can now proceed to find out the change in the population size of P, Q and S when the population of R increased.<\/p>\n Since the question specified that the population of<\/u><\/strong> R increased<\/strong><\/u> rapidly, let us first label an upward arrow beside R<\/u><\/strong> on the food web, as shown below:<\/p>\n Next, we will now identify the food relationships between P, Q, R and S by looking at the food web.<\/p>\n The food relationships are summarised below:<\/p>\n When the population of R increased rapidly, this means that there will be more R for P to feed on.<\/p>\n Thus, the population of P will increase<\/u><\/strong>, as indicated by an upward arrow<\/u><\/strong> beside P on the food web.<\/p>\n When the population of R increased rapidly, there will be more R feeding on Q and S.<\/p>\n Thus, the population of both Q and S will decrease<\/u><\/strong>, as indicated by a downward arrow<\/u><\/strong> beside Q and S on the food web.<\/p>\n The completely labelled food web will be as shown below:<\/p>\n Now that we have found out the change in population size of P, Q and S, how is the change in population size represented in graphs?<\/p>\n Since the population of P<\/u><\/strong> increases, it should be represented by an upward-sloping line<\/u><\/strong> on the graph.<\/p>\n On the other hand, since the population of Q and S<\/u><\/strong> decreases, they should be represented by downward-sloping lines<\/u><\/strong> on the graph.<\/p>\n The slope of the line for P, Q and S should be as follow:<\/p>\n With this information, let us now look at the options in the question and determine which options can be eliminated based on the slope of each line<\/u><\/strong>.<\/p>\n Let us look at option (2) first:<\/p>\n Since option (2) shows that the population of P decreases instead of increases, and the population of Q increases instead of decreases, option (2) is incorrect.<\/p>\n Next, let us look at option (4):<\/p>\n Since option (4) shows that the population of Q increases instead of decreases, option (4) is incorrect.<\/p>\n As of now, both options (2) and (4)<\/u><\/strong> \u00a0are incorrect and have been eliminated<\/u><\/strong>.<\/p>\n Let us now look at options (1) and (3):<\/p>\n Since both options (1) and (3) show that the population of P increases while the population of Q and S decreases, based on the slope of the lines alone<\/u><\/strong>, both (1) and (3) are possible answers.<\/p>\n How do we then determine if option (1) or (3) is the correct answer?<\/p>\n This is where students usually struggle.<\/p>\n \u2b50\ufe0f Tip:<\/strong> Besides checking for the slope of each line as shown above, students also have to remember to check for the initial population size<\/u><\/strong> of each organism.<\/p>\n<\/blockquote>\n To determine the initial population size<\/u><\/strong> of each organism, it is important to remember the following:<\/p>\n (1) A food web\/ chain always starts<\/u><\/strong> with a food producer<\/u><\/strong> and end<\/u><\/strong> with the \u201cKing\u201d<\/u><\/strong>.<\/p>\n By using actual organisms to represent Q, S, R and P, in the food chain below, fruits<\/u><\/strong> will be the food producer<\/u><\/strong> while the wolf<\/u><\/strong> will be the \u201cKing\u201d<\/u><\/strong>.<\/p>\n (2) As we move from the start to the end<\/u><\/strong> of the food web\/ chain, the initial population size of the organism decreases<\/u><\/strong>.<\/p>\n Why is this so?<\/p>\n Imagine a scenario where the population size of the organism increases<\/u><\/strong> from the start to the end of the food chain (2 fruits, 20 squirrels, 200 raccoons and 2000 wolves).<\/p>\n There will be insufficient food for all organisms in the food chain, causing all organisms to die<\/u><\/strong>.<\/p>\n On the other hand, when the population size of the organism decreases<\/u><\/strong> from the start to the end of the food chain (2000 fruits, 200 squirrels, 20 raccoons and 2 wolves), all the organisms will have sufficient food to feed on and survive<\/u><\/strong>.<\/p>\n Thus, we can conclude that the population size of the organism should decrease<\/u><\/strong> as we move from the<\/u><\/strong> start to the end<\/strong><\/u> of the food web\/ chain.<\/p>\n Combining points (1) and (2), we understand that:<\/p>\n Looking back at the food web in the question, Q, the food producer<\/u><\/strong>, should have the largest initial population size<\/u><\/strong> while P, the \u201cKing\u201d<\/u><\/strong>, should have the smallest initial population size<\/u><\/strong>.<\/p>\n Let us look back at options (1) and (3) again:<\/p>\n Since organism Q did not have the largest initial population size for option (1), we can now conclude that option (1) is also wrong.<\/p>\n Since Q has the largest initial population size while P has the smallest initial population size in option (3), we can conclude that the correct answer will then be option (3).<\/p>\n I hope this article has helped you gain a better understanding of how to approach Web of Life<\/a> questions.<\/p>\n In summary, to determine which graph shows the correct change in the population size of different organisms, students must always remember to check for the following:<\/p>\n Continue to keep a lookout for our new articles! \ud83d\ude42<\/p>\n [\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row disabled_on=”off|off|off” admin_label=”CCI” _builder_version=”4.21.0″ custom_margin=”0px||” custom_padding=”0px||” global_module=”239753″ saved_tabs=”all” collapsed=”off” global_colors_info=”{}”][et_pb_column type=”4_4″ _builder_version=”4.16″ custom_padding=”|||” global_colors_info=”{}” custom_padding__hover=”|||”][et_pb_divider color=”#898989″ admin_label=”Divider” _builder_version=”4.16″ locked=”off” global_colors_info=”{}”][\/et_pb_divider][et_pb_image src=”https:\/\/thepiquelab.com\/blog\/wp-content\/uploads\/2019\/05\/The-Pique-Lab-CCI-Science-Course-CTA.png” align=”center” align_tablet=”center” align_phone=”” align_last_edited=”on|desktop” admin_label=”CCI” _builder_version=”4.16″ z_index_tablet=”500″ global_colors_info=”{}”][\/et_pb_image][et_pb_text _builder_version=”4.16″ text_font=”||||||||” text_text_color=”#333333″ text_font_size=”18px” text_orientation=”center” global_colors_info=”{}”]<\/p>\n If you like our methodology, we’ve some upcoming workshops:<\/p>\n [\/et_pb_text][et_pb_text _builder_version=”4.16″ text_font=”geomanist-medium||||||||” text_text_color=”#f44a4a” text_font_size=”18px” text_line_height=”2em” text_orientation=”center” global_colors_info=”{}”]<\/p>\n P3 Complete Concept Integration\u2122 Science Course<\/strong><\/a> [\/et_pb_text][\/et_pb_column][\/et_pb_row][\/et_pb_section]<\/p>\n","protected":false},"excerpt":{"rendered":" <\/p>\n","protected":false},"author":10,"featured_media":242142,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_et_pb_use_builder":"on","_et_pb_old_content":"","_et_gb_content_width":"","om_disable_all_campaigns":false,"_lmt_disableupdate":"no","_lmt_disable":"","footnotes":""},"categories":[50,6,3,54],"tags":[],"post_folder":[],"modified_by":"Jaimie Aberia","_links":{"self":[{"href":"https:\/\/thepiquelab.com\/blog\/wp-json\/wp\/v2\/posts\/242112"}],"collection":[{"href":"https:\/\/thepiquelab.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/thepiquelab.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/thepiquelab.com\/blog\/wp-json\/wp\/v2\/users\/10"}],"replies":[{"embeddable":true,"href":"https:\/\/thepiquelab.com\/blog\/wp-json\/wp\/v2\/comments?post=242112"}],"version-history":[{"count":23,"href":"https:\/\/thepiquelab.com\/blog\/wp-json\/wp\/v2\/posts\/242112\/revisions"}],"predecessor-version":[{"id":244485,"href":"https:\/\/thepiquelab.com\/blog\/wp-json\/wp\/v2\/posts\/242112\/revisions\/244485"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/thepiquelab.com\/blog\/wp-json\/wp\/v2\/media\/242142"}],"wp:attachment":[{"href":"https:\/\/thepiquelab.com\/blog\/wp-json\/wp\/v2\/media?parent=242112"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/thepiquelab.com\/blog\/wp-json\/wp\/v2\/categories?post=242112"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/thepiquelab.com\/blog\/wp-json\/wp\/v2\/tags?post=242112"},{"taxonomy":"post_folder","embeddable":true,"href":"https:\/\/thepiquelab.com\/blog\/wp-json\/wp\/v2\/post_folder?post=242112"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}Topic Weightage In Nanyang Primary School (NYPS) P6 Prelim Examination Paper<\/h2>\n
P6 Topics<\/h3>\n
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P5 Topics<\/h3>\n
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P3\/4 Topics<\/h3>\n
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Summary<\/h3>\n
![\"\"](\"https:\/\/thepiquelab.com\/blog\/wp-content\/uploads\/2023\/02\/Screenshot-2023-02-06-at-2.59.51-PM.png\")
<\/p>\nRead Also:<\/h3>\n
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Question Analysis<\/h2>\n
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<\/a><\/p>\nThought Process<\/h2>\n
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<\/p>\nSuggested Answer<\/h2>\n
Moving Forward<\/h2>\n
\n
P4 Complete Concept Integration\u2122 Science Course<\/strong><\/a>
P5 Complete Concept Integration\u2122 Science Course<\/strong><\/a>
P6 Complete Concept Integration\u2122 Science Course<\/strong><\/a><\/p>\n