Life Sciences Grade 11 Eastern Cape November 2013 Memo (Eng)

Downloaded from hlayiso.com NATIONAL SENIOR CERTIFICATE GRADE 11 NOVEMBER 2013 LIFE SCIENCES P2 MEMORANDUM MARKS: 150 This memorandum consists of 8 pages.

Downloaded from hlayiso.com 2 LIFE SCIENCES P2 (NOVEMBER 2013) SECTION A QUESTION 1 1.1 1.1.1 A  1.1.2 A  1.1.3 B  1.1.4 C  1.1.5 A  1.1.6 D  1.1.7 C  1.1.8 D  1.1.9 D  1.1.10 B  (10 x 2) (20) 1.2 1.2.1 Mycelium  1.2.2 Coccus  1.2.3 Symbiosis  1.2.4 Cephalisation  1.2.5 Antibiotics  1.2.6 Coelom  1.2.7 Seed banks  1.2.8 Segmentation  1.2.9 Endosperm  1.2.10 Sessile  (10 x 1) (10)

Downloaded from hlayiso.com (NOVEMBER 2013) LIFE SCIENCES P2 3 1.3 1.3.1 A only  1.3.2 A only  1.3.3 None  1.3.4 B only  1.3.5 B only  1.3.6 Both A and B  1.3.7 Both A and B  1.3.8 A only  1.3.9 B only  1.3.10 None  (10 x 2) (20) TOTAL SECTION A: 50

Downloaded from hlayiso.com 4 LIFE SCIENCES P2 (NOVEMBER 2013) SECTION B QUESTION 2 2.1 2.1.1 Injection  Orally  (2) 2.1.2 dead or weakened germs  (1) 2.1.3 T-lymphocytes  (1) 2.1.4 It increased slowly to about day 50  where it is at its highest and then it decreased.  (2) 2.1.5 It increased rapidly in the first ±30 days  / (±day 140) / to its maximum, then levelled off and stayed constant  until up to over 280 days. (2) 2.2 2.2.1 Guideline for the assessing of the graph Correct type of graph 1 Title of graph 1 Correct label and scale of x-axis 1 Correct label and scale of y-axis 1 Plotting of points 1: 1 to 2 points plotted correctly 2: 3 to 4 points plotted correctly 3: all 5 points plotted correctly NOTE: If the wrong type of graph is drawn, 4 marks will be lost for:  ‘Correct type of graph  ‘Plotting of points’ If labels of the axes are transposed then 2 marks will be lost for: *‘Correct label and scale for X- and Y axes’ (7)

Downloaded from hlayiso.com (NOVEMBER 2013) LIFE SCIENCES P2 5 2.2.2 70  %  (2) 2.2.3 No.  PEP drugs are only effective if taken up to 72/76  hours after exposure. (2) 2.3 2.3.1 A – bilateral  B – asymmetrical  C – radial  (3) 2.3.2 A: These animals usually move,  as the central nervous system allows them to coordinate complex movements  e.g. flying. C: Allows animals to view the environment equally from all sides.  (3) 2.4 2.4.1 2010: 333  2011: (8 + 7 + 4 + 250 + 58 + 121)  = 448 (333 + 448)  = 781  (4) 2.4.2 Black Rhino White Rhino 1997 2010 1997 2010 1 043 1 916 1 043 1 916 1 mark for correct values for 1997 for both black and white rhinos 1 mark for correct values for 2010 for both black and white rhinos 1 mark for correct captions 1 mark for drawing of table (4) 2.4.3 White rhino numbers have steadily increased  until 2009 but by 2010 numbers started to drop.  An increase in numbers is because of efforts to protect the rhino.  Decrease in numbers is mainly due to poaching as result of the high price for rhino horn.  (4) 2.4.4  Providing better protection  for rhinos in game reserves.  Increase numbers of anti-poaching teams  such as the army.  Allow farmers to breed rhino  and  To harvest the horn to sell  which can be done annually  This will help to reduce black market prices   Sale of horns to be legalised and regulated   Educate people about the real medicinal value of rhino horns.  (Any 3 x 1) (3) [40]

Downloaded from hlayiso.com 6 LIFE SCIENCES P2 (NOVEMBER 2013) QUESTION 3 3.1 3.1.1   = 1 800  tons (3) 3.1.2 - There could be littering  when wind blows plastic bags into surrounding areas.  - The ground water could be polluted  when chemicals drain through to the bottom of the landfill when it rains.  - Air pollution occurs  when the waste is burned.  (Any 2 x 2) (4) 3.1.3 - They could have compost heaps and not throw away organic waste.  (Any other acceptable answer.) (1) 3.2 3.2.1 - If plants are removed less carbon dioxide will be absorbed from the atmosphere via photosynthesis.  - The concentration of CO2 in the air will not be reduced  - thus increasing the amount of greenhouse gases in the air  (Any 3 x 1) (3) 3.2.2 - Forest floors have a thin layer of topsoil,  held firmly by the root system  of trees and shrubs - When deforestation occurs, this layer of topsoil rapidly washes away  - Leaving the subsoil bare, forming dongas and erosion scars.  (Any 3 x 1) (3) 3.2.3 - If plants are removed, less water is absorbed  by plant roots when it rains.  - This results in less water passing through the plants and less water vapour is later released into the atmosphere  by transpiration.  (Any 3 x 1) (3) 3.3 3.3.1 - The amount of ozone depletion increased  from 1982 to 1986 - Then there was a slight decrease to 1988  and - an increase until 1994  - Since 1994, ozone depletion has decreased.  (4) 3.3.2 6 000 tons  (1) 3.3.3 CO2,  methane,  nitrogen oxide;  water vapour in fog ; surface ozone  (Any 3 x 1) (3) 3.3.4 CFC’s can carry on destroying the ozone.  (1)

Downloaded from hlayiso.com (NOVEMBER 2013) LIFE SCIENCES P2 7 3.3.5 - Legislation was passed  forcing countries to control pollution from industries. - CFC’s were replaced by law  by less harmful substances in fridges and cooling devices, - Lead free petrol was introduced  - People were educated  and become more aware of the problem. (Any 3 x 1) (3) 3.4 3.4.1 A Phylogenetic tree is a diagram that shows the evolutionary relationship  among a group of organisms.  (2) 3.4.2 (a) False.  The circle numbered 2 represents the common ancestor of the protea bush, palm tree and maize plant.  OR The circle numbered 3 represent the common ancestor of the palm tree and maize plant.  (2) (b) False.  Proteas are more closely related to maize plants because they share a more recent common ancestor.  (2) (c) False.  Palm trees and pine trees share a common ancestor which is now extinct.  (2) (d) True.  They all share a common ancestor that had flowers.  (2) 3.4.3 100 million years ago (1) [40] TOTAL SECTION B: 80

Downloaded from hlayiso.com 8 LIFE SCIENCES P2 (NOVEMBER 2013) SECTION C QUESTION 4 4.1 - Eutrophication is the addition of high levels of nutrients especially nitrogen and phosphorus to water.  - It is caused by allowing untreated sewage to flow into rivers or wetlands - Also when fertilisers get washed into rivers, streams.  - or when fertiliser industries pour waste into rivers, streams  - The extra nutrients allow the algae and other aquatic plants to grow  - and reproduce very quickly and cover the surface of the water.  - The rapid growth of algae is called an algal bloom.  - Certain algae in algal blooms can release toxins into the water  - that are harmful to humans and other animals.  - The algae become overcrowded and eventually they die  - due to a lack of sunlight.  - Bacteria in the water decompose the dead plant material.  - The bacteria use up a lot of the oxygen in the water during decomposition - As a result, aquatic animals e.g. fish insects etc. die  - due to a lack of oxygen.  (Any 8 x 1) - Acid Mine Drainage (AMD) is the drainage of highly acidic water from mines onto the surface of the land or into groundwater.  - Acid mine water is formed when groundwater flows over the rocks in old mine shafts and tunnels in gold and coal mines.  - The water dissolves sulphide minerals out of the rocks  - which form sulphuric acid.  - The sulphuric acid lowers the pH  of the water. - The sulphuric acid in turn dissolves metals out of the rocks.  - These metals include toxic heavy metals such as manganese, and radioactive practices.  - Radium and uranium are radioactive elements which release radiation  - into the environment, which is very harmful to living organisms.  - Acid mine water gradually fills up old mines and rises to the surface  - where it spreads out and pollutes rivers and wetlands and harms or kills plants and animals  that are in contact with the water - It also moves into underground water supplies  - which may be used for irrigation or drinking and will therefore harm plants and animals in this way too.  (Any 9 x 1) (17) ASSESSING THE PRESENTATION OF THE ESSAY Marks Descriptions 3 Well structured – demonstrates insight and understanding of question. 2 Minor gaps in the answer. 1 Attempted but with significant gaps in the answer. 0 Not attempted/nothing written other than question number. Synthesis (3) TOTAL SECTION C: 20 GRAND TOTAL: 150