
	Trending ▼ ICSE CBSE 10th ISC CBSE 12th CTET GATE UGC NET Vestibulares ResFinder

GCE JUN 2006 : (AS 2) Physiology and Ecology

16 pages, 33 questions, 0 questions with responses, 0 total responses,

	gce	+Fave Message
	Profile Timeline Uploads Q & A

Home > gce >

Instantly get Model Answers to questions on this ResPaper. Try now!
NEW ResPaper Exclusive!

Formatting page ...

Centre Number 71 Candidate Number ADVANCED SUBSIDIARY (AS) General Certificate of Education 2006 Biology assessing Module 2: Physiology and Ecology ASB21 Assessment Unit AS 2 [ASB21] TUESDAY 20 JUNE, MORNING TIME 1 hour. INSTRUCTIONS TO CANDIDATES Write your Centre Number and Candidate Number in the spaces provided at the top of this page. Write your answers in the spaces provided in this question paper. Answer all eight questions. 1 31.5.05BP 2 8.8.05RTS 3 22.9.05BP INFORMATION FOR CANDIDATES The total mark for this paper is 55. Section A carries 43 marks. Section B carries 12 marks. You should spend approximately 15 minutes on Section B. You are expected to answer Section B in continuous prose. Quality of written communication will be assessed in Section B. Figures in brackets printed down the right-hand side of pages indicate the marks awarded to each question or part question. For Examiner s use only Question Number 1 2 3 4 5 6 7 8 Total Marks ASB2S6 747 Marks Section A Examiner Only Marks 1 Remark When a blood sample is spun at high speed for several minutes in a centrifuge, it settles into two distinct layers as shown in the diagram and table below. PLASMA (55%) Blood components Function CELLS (45%) Source: Biology, Revise through diagrams, W. R. Pickering, Oxford University Press, 1996 (a) Complete the table above by identifying one function for each of the blood components illustrated. [4] (b) Outline two possible functions for the blood plasma. 1. _______________________________________________________ _________________________________________________________ 2. _______________________________________________________ 1 31.5.05BP 2 8.8.05RTS 3 22.9.05BP ______________________________________________________ [2] ASB2S6 747 2 [Turn over 2 (a) Distinguish between biotic and abiotic factors in an ecosystem, and give an example of each. Examiner Only Marks Remark _________________________________________________________ _________________________________________________________ _________________________________________________________ ______________________________________________________ [2] (b) (i) Explain what is meant by the term trophic level . ______________________________________________________ ___________________________________________________ [1] (ii) Name the different trophic levels within a community. ______________________________________________________ ___________________________________________________ [1] (c) Compare and contrast the terms gross primary productivity and net primary productivity . _________________________________________________________ _________________________________________________________ _________________________________________________________ 1 31.5.05BP 2 8.8.05RTS 3 22.9.05BP ______________________________________________________ [2] ASB2S6 747 3 [Turn over 3 (a) Cardiac muscle is described as myogenic. What is meant by the term myogenic ? Examiner Only Marks Remark _________________________________________________________ ______________________________________________________ [1] (b) The diagram below shows the spread of impulses through the heart and the time taken (in seconds) to reach the various parts. sino-atrial node atrioventricular node 0.0s 0.06s 0.02 s 0.19 s 0.12s 0.18s 0.17 s 0.16s bundle of His Source: AS Level Biology, Phil Bradfield, John Dodds, Judy Dodds and Norma Taylor, 2001 (i) Using the information in the diagram, suggest the time period during which atrial systole takes place. ______________________________________________________ ___________________________________________________ [1] 3 22.9.05BP (ii) The atria have completed contraction by the time that initial impulses are fired in the ventricles. What causes this delay in the transmission of impulses to the ventricles? 2 8.8.05RTS ______________________________________________________ 1 31.5.05BP ___________________________________________________ [1] ASB2S6 747 4 [Turn over (iii) Describe the path of impulse transmission within the ventricles. Examiner Only Marks Remark ______________________________________________________ ___________________________________________________ [1] (iv) What is the advantage of the path of excitation described in (iii) to the pumping of blood out of the ventricles? ______________________________________________________ 1 31.5.05BP 2 8.8.05RTS 3 22.9.05BP ___________________________________________________ [1] ASB2S6 747 5 [Turn over 4 The diagram below represents the arrangement of cells in part of the root of a dicotyledonous plant together with two possible routes taken by water entering the vascular tissue. 21 Pit Xylem vessel C A B Casparian strip Pericycle cell Source: Biology Principles and Processes, Roberts, Reiss and Monger, Nelson, 1993. (a) Identify the cell types labelled A to C. Examiner Only Marks Remark A _______________________________ B _______________________________ C _______________________________ [3] (b) Which of the arrows, 1 or 2, represents the symplast pathway of water movement? ______________________________________________________ [1] (c) What makes up the Casparian strip in cell type C and what is its function in water transport? _________________________________________________________ 3 22.9.05BP _________________________________________________________ _________________________________________________________ 1 31.5.05BP 2 8.8.05RTS ______________________________________________________ [2] ASB2S6 747 6 [Turn over (d) Describe one way in which xylem vessels are adapted for their function of water transport. Examiner Only Marks Remark _________________________________________________________ 1 31.5.05BP 2 8.8.05RTS 3 22.9.05BP ______________________________________________________ [1] ASB2S6 747 7 [Turn over 5 The graph below shows the pressure changes in the thorax and the lungs during a cycle of breathing (inspiration plus expiration). (The atmospheric pressure is 101 kPa.) Inspiration Examiner Only Marks Remark Expiration Thorax Pressure/kPa 101 Lungs 100 0 1 2 Time/s 3 4 (a) Using your understanding of breathing, give one reason for the change in thoracic pressure (i) during inspiration ______________________________________________________ ___________________________________________________ [1] (ii) during expiration. 3 22.9.05BP ______________________________________________________ 1 31.5.05BP 2 8.8.05RTS ___________________________________________________ [1] ASB2S6 747 8 [Turn over (b) Explain the changes in the lung pressure during inspiration. Examiner Only Marks Remark _________________________________________________________ _________________________________________________________ _________________________________________________________ ______________________________________________________ [2] (c) Using the information in the graph opposite, calculate the rate of breathing in breaths per minute. (Use the space below to show your working.) 1 31.5.05BP 2 8.8.05RTS 3 22.9.05BP Answer _________ [2] ASB2S6 747 9 [Turn over The graph shows the abundance of phytoplankton (microscopic plants) throughout one year in the surface waters of a lake. The changing amounts of light and phosphate ions in the water are also shown in the graph. Phosphate ions are necessary for the growth of the phytoplankton. 100 Dry mass of phytoplankton/g m 3 4 3 75 2 50 1 25 0 0 Jan Feb Mar Apr May Jun Jul Aug Sep Months of the year Oct Nov Dec Light intensity and phosphate ion concentrations /arbitrary units 6 phytoplankton light phosphate ions 0 The phytoplankton population increased during March and April as the phosphate ion concentration was high and there was more light in these spring months. Examiner Only Marks Remark (a) Describe and suggest an explanation for the changes in the phytoplankton population during the following months of the year. May: ____________________________________________________ _________________________________________________________ _________________________________________________________ 3 22.9.05BP ______________________________________________________ [2] September: _______________________________________________ 2 8.8.05RTS _________________________________________________________ _________________________________________________________ 1 31.5.05BP ______________________________________________________ [2] ASB2S6 747 10 [Turn over (b) Zooplankton (microscopic animals) feed on the phytoplankton. The zooplankton populations peak twice during the year. During which months are these peaks most likely to occur? Explain your choice. Examiner Only Marks Remark _________________________________________________________ _________________________________________________________ _________________________________________________________ 1 31.5.05BP 2 8.8.05RTS 3 22.9.05BP ______________________________________________________ [2] ASB2S6 747 11 [Turn over 7 The mass of a plant was recorded at 3 hour intervals over a period of 24 hours. The results are shown in the table below. The table also shows the lighting conditions during the day. The plant was exposed to air currents for a 3 hour period starting at 1 pm (indicated by an asterisk [*] in the table). Time of day Lighting conditions Dark 134.6 4 am Dark 134.2 7 am Light 133.7 10 am Light 128.7 1 pm* Light 122.6 4 pm Light 107.7 7 pm Light 106.9 10 pm Dark 106.8 1 am Dark Remark Mass of the plant/g 1 am Examiner Only Marks 106.8 (a) Describe precisely how water leaves a plant. _________________________________________________________ _________________________________________________________ _________________________________________________________ ______________________________________________________ [2] (b) (i) Determine the change in mass over the first six hours (up to 7 am) and the change in mass over the next six hours (from 7 am to 1 pm). 1 am to 7 am: __________________________________________ 3 22.9.05BP 7 am to 1 pm: _______________________________________ [1] 2 8.8.05RTS ______________________________________________________ 1 31.5.05BP (ii) Explain the different rates of water loss described in (i). ___________________________________________________ [1] ______________________________________________________ ASB2S6 747 12 [Turn over (c) Explain what happens during the hours when the plant was exposed to air currents. Examiner Only Marks Remark _________________________________________________________ _________________________________________________________ _________________________________________________________ ______________________________________________________ [2] (d) What evidence is there that this plant is drying out? _________________________________________________________ 1 31.5.05BP 2 8.8.05RTS 3 22.9.05BP ______________________________________________________ [1] ASB2S6 747 13 [Turn over Section B Examiner Only Marks Remark In this section you are expected to answer in continuous prose, supported, where appropriate, by diagrams. You are reminded that up to two marks in this question are awarded for the quality of written communication. [2] 8 Give an account of the roles of haemoglobin and myoglobin in providing respiring tissues with oxygen. [10] Haemoglobin _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ 2 8.8.05RTS _____________________________________________________________ _____________________________________________________________ 1 31.5.05BP 3 22.9.05BP _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ ASB2S6 747 14 [Turn over Examiner Only _____________________________________________________________ Marks Remark _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ Myoglobin _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ 2 8.8.05RTS _____________________________________________________________ _____________________________________________________________ 1 31.5.05BP 3 22.9.05BP _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ ASB2S6 747 15 [Turn over 3 22.9.05BP 2 8.8.05RTS 1 31.5.05BP Permission to reproduce all copyright material has been applied for. In some cases, efforts to contact copyright holders may have been unsuccessful and CCEA will be happy to rectify any omissions of acknowledgement in future if notified. S 5/05 5500 302507(40) [Turn over

Formatting page ...

Additional Info : Gce Biology June 2006 Assessment Unit AS 2 Module 2: Physiology and Ecology
Tags : General Certificate of Education, A Level and AS Level, uk, council for the curriculum examinations and assessment, gce exam papers, gce a level and as level exam papers , gce past questions and answer, gce past question papers, ccea gce past papers, gce ccea past papers

gce chat

Horizontal lines at:
Guest Horizontal lines at:
AutoRM Data:
Box geometries: