Agricultural Sciences Grade 11 P1 2017 Memo (Eng)

Downloaded from hlayiso.com NATIONAL SENIOR CERTIFICATE GRADE 11 NOVEMBER 2017 AGRICULTURAL SCIENCES P1 MARKING GUIDELINE MARKS: 150 This marking guideline consists of 9 pages.

Downloaded from hlayiso.com 2 AGRICULTURAL SCIENCES P1 (EC/NOVEMBER 2017) SECTION A QUESTION 1 1.1 1.1.1 A √√ 1.1.2 C √√ 1.1.3 C √√ 1.1.4 D √√ 1.1.5 B √√ 1.1.6 C √√ 1.1.7 B √√ 1.1.8 A √√ 1.1.9 D √√ 1.1.10 B √√ (10 x 2) (20) 1.2 1.2.1 B only √√ 1.2.2 A only √√ 1.2.3 None √√ 1.2.4 B only √√ 1.2.5 Both A and B √√ (5 x 2) (10) 1.3 1.3.1 Sucrose √√ 1.3.2 Catenate √√ 1.3.3 Capillarity / Capillary √√ 1.3.4 Bulk density √√ 1.3.5 Mottled √√ (5 x 2) (10) 1.4 1.4.1 Ethanol √ 1.4.2 Structure √ 1.4.3 Carbon dioxide √ 1.4.4 Hygroscopic / Adhesion √ 1.4.5 Immobilisation √ (5 x 1) (5) TOTAL SECTION A: 45 Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/NOVEMBER 2017) AGRICULTURAL SCIENCES P1 3 SECTION B QUESTION 2: BASIC AGRICULTURAL CHEMISTRY 2.1 Organic compounds 2.1.1 Identification of compound and mixture A – compound √ (1) B – mixture √ (1) 2.1.2 Difference between A (compound) and B (mixture):  Constituent of a mixture can be separated by physical means √ and constituents of a compound cannot √  Composition of a mixture can vary √ and composition of a compound is fixed √ (Any 1 x 2) (2) 2.1.3 Diagram showing chemical bond of water Criteria for marking of the diagram: 1 mark – hydrogen atoms √ 1 mark – oxygen atom √ 1 mark – correct bonding with valence electrons √ (3 x 1) (3) 2.2 Fats / Lipids 2.2.1 Classification of food A and B A – Saturated fat √ (1) B – Unsaturated fat √ (1) 2.2.2 Identification of fat to be included in a diet Unsaturated fat / fat in food B / Sunflower oil √ (1) 2.2.3 Reason for fat included in a diet It is of plant origin √ and can lower cholesterol levels in blood/ lowers risk of heart attack √ / Lowers risk of some cancers √ (Any 2) (2) Copyright reserved Please turn over

Downloaded from hlayiso.com 4 AGRICULTURAL SCIENCES P1 (EC/NOVEMBER 2017) 2.2.4 Distinguishing between food A and food B (a) Melting point – Food A – has a high melting point √ Food B – has a low melting point √ (2) (b) Bond between carbon atoms Food A – single bond between carbon atoms √ Food B – double bond between carbon atoms √ (2) 2.3 Protein 2.3.1 Building block of protein Amino acids √ (1) 2.3.2 Difference between simple and complex protein  Simple proteins only yield amino acids if broken down √  Complex proteins are simple proteins combined with some non- protein material √ (2) 2.3.3 Reason for giving animals protein in each of the following situation: (a) Racing horse – It builds collagen structures which give strength to the animal √ (1) (b) Injured animal – It repairs worn out and damaged cells √ (1) (c) Newly born animal – Needed for the development of new cells /growth √ (1) 2.4 Organic compound 2.4.1 Providing labels A - Propane √ B – C3H8 √ C – Hydroxyl/ OH √ D H H H C C OH √√ H H E – Ethanoic acid √ F – Carboxyl / COOH √ G – CH3 √ COOH √ (9) 2.4.2 Importance of Ethanoic acid  It is used to preserve food √ (1) Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/NOVEMBER 2017) AGRICULTURAL SCIENCES P1 5 2.5 Carbohydrates 2.5.1 Classification of food into carbohydrate types Potatoes – Polysaccharide √ Sugar – Monosaccharide √ (2) 2.5.2 Chemical formula of the monosaccharide C6H12O6 √ (1) [35] QUESTION 3: SOIL SCIENCE 3.1 Soil texture 3.1.1 Determination of percentage of sand and clay (a) Clay loam: Sand between 31% – 45% √ Clay between 21% – 39% √ (2) (b) Silt loam: Sand between 12% – 45% √ Clay between 5% – 18% √ (2) 3.1.2 Influence of clay on the following: (a) Tillability of soil – Clay soil is hard to till √because of cohesive forces √ (2) (b) Drainage of soil – Drainage of soil with a high clay content is low √ due to micro-pores √ (2) 3.1.3 Indication of texture ideal for cultivation Loam √ (1) 3.2 Handling facility 3.2.1 Formulation of hypothesis In clay soil water moves slowly√ to reach the greatest height √ OR Sandy soil has a low capillarity √ than clay soil/ vice versa √ (Any 1 x 2) (2) 3.2.2 Type of water movement demonstrated Capillary movement / Capillarity √ (1) 3.2.3 Labelling of soils Soil A – Clay √ Soil B – Sand √ Soil C – Loam/silt √ (3) Copyright reserved Please turn over

Downloaded from hlayiso.com 6 AGRICULTURAL SCIENCES P1 (EC/NOVEMBER 2017) 3.2.4 Indicating the soil where the following occurs (a) Water rises most rapidly – Sand √ (1) (b) Water rises the slowest – Clay √ (1) 3.2.5 Reason for the answer The rapid rise of water in sandy soil is the result of a large number of macro-pores which allow rapid water movement √ and the micro- pores in clay retard the motion of water √ (2) 3.3 Soil temperature 3.3.1 Bar graph Temperature at various depths at various times of the day 30 25 Temperature (0C) 20 Surface 15 20cm deep 10 5 0 06:00 08:00 10:00 12:00 14:00 16:00 18:00 Time of the day Criteria/rubric/marking guidelines  Correct heading √  X-axis: Correctly calibrated with label (Time of the day) √  Y-axis: Correctly calibrated with label (Temperature) √  Correct unit (°C) √  Correct type of graph (Bar graph) √  Correct plotting √ (6) 3.3.2 Identification of the problem of temperature on the surface Temperature variation is high √ (1) 3.3.3 TWO ways to minimise the situation  Mulching/surface cover material √  Shading √  Clear plastic covers √  Irrigation √ (Any 2 x 1) (2) Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/NOVEMBER 2017) AGRICULTURAL SCIENCES P1 7 3.4 Indication of the cause of soil colours 3.4.1 Black – Presence of organic matter √ (1) 3.4.2 Red – Oxidised iron √ (1) 3.4.3 Grey – Waterlogged soil condition √ (1) 3.5 Pore space 3.5.1 Influence of soil depth on pore space Total pore space decreases √ with an increase in soil depth √ (2) 3.5.2 Influence of crumb structure on pore space Soils with a loose, crumb structure have a larger √ pore space √ (2) [35] Copyright reserved Please turn over

Downloaded from hlayiso.com 8 AGRICULTURAL SCIENCES P1 (EC/NOVEMBER 2017) QUESTION 4: SOIL SCIENCE 4.1 Soil morphology 4.1.1 Identification of soil profiles A – Young soil √ B – Adult soil √ C – Wet soil √ D – Eroded soil √ (4 x 1) (4) 4.1.2 Naming of the horizon (a) B horizon √ (b) A horizon √ (c) C horizon √ (3) 4.2 Soil classification 4.2.1 Re-arrangement of steps in soil classification  Demarcate master horizons √  Identify diagnostic horizons √  Establish soil form √  Series characteristics are identified √  Determine soil series √ (5 x 1) (5) 4.2.2 Explanation of a binomial soil classification Soil classification contains two categories i.e. broad and a more general level soil form √ and a lower and more specific level soil series √ (2) 4.3 Soil organisms 4.3.1 Classification of organisms in pictures A and B Picture A – micro-organisms √ Picture B – macro-organisms √ (2) 4.3.2 THREE conditions needed for the survival of these organisms  Soil fertility √  Soil moisture √  Suitable soil temperature √  Soil aeration √  Light √  Soil pH √ (Any 3 x 1) (3) Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/NOVEMBER 2017) AGRICULTURAL SCIENCES P1 9 4.3.3 Explanation of how the organisms improve the following: (a) Soil structure – Secretions of these organisms √ help with the aggregation of soil particles √ (2) (b) Soil fertility – They release carbon dioxide which reacts with water to form carbonic acid √ which aids in the release of plant nutrients √ OR – They break down plant and animal remains √ to release nutrients √ (2) 4.4 Soil alkalinity and salinity 4.4.1 Prediction of the soil pH Farm A – above 8,5 √ Farm B – between 7,5 and 8,5 √ (2) 4.4.2 Indication of the common terms describing pH levels Farm A – alkalinity √ Farm B – salinity √ (2) 4.4.3 Salts predominating in Farm A soil Sodium carbonates and bicarbonates √ (1) 4.4.4 TWO measures to correct condition of soil in farm A  Adding gypsum √  Scraping √  Flushing √  Leaching √ (Any 2 x 1) (2) 4.5 Soil colloids 4.5.1 Example of organic colloid Humus √ (1) 4.5.2 Differentiation between organic and inorganic colloids with regard to shape  Inorganic colloids have a layered structure with flat platelets √  Organic colloids are structureless/ amorphous √ (2) 4.5.3 Explanation of how organic and inorganic colloids improve soil fertility They are negatively charged √ and attract positively charged ions/ nutrients √ (2) [35] TOTAL SECTION B: 105 GRAND TOTAL: 150 Copyright reserved Please turn over