Agricultural Sciences Grade 11 P1 2016 Memo (Eng)

Downloaded from hlayiso.com NATIONAL SENIOR CERTIFICATE GRADE 11 NOVEMBER 2016 AGRICULTURAL SCIENCES P1 MEMORANDUM MARKS: 150 This memorandum consists of 9 pages.

Downloaded from hlayiso.com 2 AGRICULTURAL SCIENCES P1 (EC/NOVEMBER 2016) SECTION A QUESTION 1 1.1 1.1.1 C √√ 1.1.2 D √√ 1.1.3 C √√ 1.1.4 A √√ 1.1.5 B √√ 1.1.6 B √√ 1.1.7 D √√ 1.1.8 A √√ 1.1.9 D √√ 1.1.10 C √√ (10 x 2) (20) 1.2 1.2.1 A only √√ 1.2.2 B only √√ 1.2.3 B only √√ 1.2.4 None √√ 1.2.5 Both A and B √√ (5 x 2) (10) 1.3 1.3.1 Sucrose √√ 1.3.2 Periodic table √√ 1.3.3 Bulk density √√ 1.3.4 Mottled √√ 1.3.5 Alkalinity √√ (5 x 2) (10) 1.4 1.4.1 Covalent bonding √ 1.4.2 Field water capacity √ 1.4.3 G-horizon √ 1.4.4 Immobilisation √ 1.4.5 Acidity √ (5 x 2) (10) TOTAL SECTION A: 45 Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/NOVEMBER 2016) AGRICULTURAL SCIENCES P1 3 SECTION B QUESTION 2: BASIC AGRICULTURAL CHEMISTRY 2.1 2.1.1 Identification of compound Sodium chloride √ (1) 2.1.2 Indication of health benefit of sodium chloride It inhibits the growth of bacteria √ (1) 2.1.3 Naming of the parts A – Nucleus √ B – Shell/orbit/energy level √ C – Electron √ (3) 2.1.4 Indication of the group of the elements Na – Alkali metals/group 1 √ Cl – Halogens/group V11 √ (2) 2.1.5 TWO common characteristics of elements in group 17  They are electron acceptors. √  They are chemically reactive √  Usually poisonous √ (Any 2 x 1) (2) 2.2 Carbohydrates 2.2.1 Disaccharide formed from glucose and fructose Sucrose √ (1) 2.2.2 Disaccharide formed from glucose and galactose Lactose √ (1) 2.2.3 Chemical formula for sucrose and lactose C12H22O11 √√ (2) 2.2.4 Importance of starch: (a) Racing – It provides energy to animals. √ (b) Selling – It fattens animals. √ (2) 2.3 Compounds in agriculture 2.3.1 Classification of compounds A and C A – Organic compound √ C – Inorganic compound √ (2) 2.3.2 Name of the fatty acid A and B A – Unsaturated fatty acid √ B – Saturated fatty acid √ (2) 2.3.3 Letter representing a fatty acid (a) B √ (b) A √ (2) Copyright reserved Please turn over

Downloaded from hlayiso.com 4 AGRICULTURAL SCIENCES P1 (EC/NOVEMBER 2016) 2.3.4 TWO importance of compound C  Acts as a solvent. √  Facilitates chemical reactions. √  Acts as a transport medium. √  It regulates temperature. √  Main source of hydrogen and oxygen. √  80–90% of all living material consists of water. √ (Any 2 x 1) (2) 2.4 Chemical formula of substances 2.4.1 Identification of chemical formula (a) Alkali – NaOH √ (b) Acid – HCl √ (2) 2.4.2 Chemical reaction when HCl dissolves in water √ H+ HCl + H2O √ Cl- + H3O+ √ (Acid) (water) (chloride) (hydronium ion) (3) 2.5 Products displayed 2.5.1 Identification of the functional group of products A and B. Product A and B – Hydroxyl group/OH √ (1) 2.5.2 Scientific name of both products Product A – Ethanol √ Product B – Methanol √ (2) 2.5.3 Identification of product ideal for heating Product B √ (1) 2.5.4 Structural formula of product B H H C√ OH √ H (2) 2.5.5 Scientific name of an oxidised ethanol Ethanoic acid √ (1) [35] Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/NOVEMBER 2016) AGRICULTURAL SCIENCES P1 5 QUESTION 3: SOIL SCIENCE 3.1 Soil structure 3.1.1 Identification of the structure A – Prism-like structure √ D – Platy structure √ (2) 3.1.2 Indication of the letter representing the structure (a) C√ (b) D√ (2) 3.1.3 Structure recommended for crop production B√ (1) 3.1.4 THREE reasons for structure recommended  Improved root penetration √  Greater water infiltration/retention and availability √  Improved biological activity √  Improved organic matter content √  Improved emergence of seedlings √  Reduced soil crusting √  Reduced erosion √ (Any 3 x 1) (3) 3.2 Soil texture 3.2.1 Identification of soil texture Sample A – Sandy soil √ Sample C – Clay soil √ (2) 3.2.2 ONE reason for each structure identified Sample A – Sandy  More macro-pores √  Less micro-pores √  High drainage and percolation √ (Any 1 x 1) (1) Sample C – Clay  Less macro-pore √  More micro-pores √  No drainage and percolation √ (Any 1 x 1) (1) 3.2.3 Letter representing the sample influencing soil characteristics. (a) Sample C √ (b) Sample A √ (c) Sample C √ (d) Sample A √ (4) Copyright reserved Please turn over

Downloaded from hlayiso.com 6 AGRICULTURAL SCIENCES P1 (EC/NOVEMBER 2016) 3.3 Bulk density of soil samples 3.3.1 Bar graph Marking graph with the following checklist Criteria Yes: 1 mark No: 0 mark 1. Bar graph 1 0 2. Y-axis labelled 1 0 3. X-axis labelled 1 0 4. Points correctly plotted 1 0 5. Correct heading 1 0 6. Units 1 0 (6) 3.3.2 Identification of undisturbed soil Soil A √ (1) 3.3.3 TWO reasons  Has a lower bulk density √  Has a higher percentage of pore space √ (2) 3.3.4 Calculation of bulk density Mass (g) Bulk density = √ Volume (cm3) 880 g = √ 500 cm3 = 1,76 g/cm3 √ (3) Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/NOVEMBER 2016) AGRICULTURAL SCIENCES P1 7 3.4 Soil gases 3.4.1 Carbon dioxide √ (1) 3.4.2 Nitrogen √ (1) 3.4.3 Oxygen √ (1) 3.5 Indication of plant response to different soil water conditions 3.5.1 Plants will die √ (1) 3.5.2 Plants will grow optimally √ (1) 3.5.3 Plants will wither √ (1) 3.5.4 Plants will die √ (1) [35] Copyright reserved Please turn over

Downloaded from hlayiso.com 8 AGRICULTURAL SCIENCES P1 (EC/NOVEMBER 2016) QUESTION 4: SOIL SCIENCE 4.1 Soil morphology 4.1.1 Determination of age of the soil Matured/old soil √ (1) 4.1.2 Reason  Horizons are clearly differentiated. √√  Significantly developed soil profile. √√ (Any 1 x 2) (2) 4.1.3 Soil profile O O A A B OR B √√ C C (2) 4.1.4 Indication of the letter representing a horizon (a) C√ (1) (b) B√ (1) 4.1.5 TWO diagnostic horizons of the horizon labelled B  Humic √  Vertic √  Melanic √  Orthic √ (Any 2 x 1) (2) 4.2 Cation adsorption 4.2.1 Identification of the form of acidity Labelled A – Reserve acidity √ Labelled B – Active acidity √ (2) 4.2.2 Justification Reserve acidity – Hydrogen ions are bound onto soil colloid. √ Active acidity – Hydrogen ions are concentrated on soil solution. √ (2) 4.2.3 Indication of the letter representing acidity that have an effect on plant B√ (1) 4.2.4 Reason Plants use plant nutrients dissolved in soli solution. √ (1) 4.2.5 Appropriate term for ability of soil to exchange cations Cation exchange capacity √ (1) Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/NOVEMBER 2016) AGRICULTURAL SCIENCES P1 9 4.3 Sodic and saline soils Comparing sodic and saline soils SODIC SOIL SALINE SOIL 4.3.1 (a) Dominant Sodium Chloride and sulphates of salts carbonates√ sodium, calcium, magnesium √ (2) (b) Colour Black √ White √ (2) 4.3.2 Exchange reaction of sodic soils √ Na+ √ + CaSO4 √ √ Ca2+ + NaSO4 √ (3) 4.4 TWO ways the soil benefit from breaking down of plant and animal residue  The decay process √ releases nutrients to the soil. √  Formation of humus √ leads to improved soil structure. √ (4) 4.5 Processes during nitrogen cycle 4.5.1 Identification of the processes A Assimilation √ B Denitrification √ C Nitrification √ D Mineralisation √ (4) 4.5.2 Soil conditions favouring denitrification Wet conditions √ (1) 4.6 Organic matter 4.6.1 THREE practices leading to the decline of organic matter  Intensive tillage √  Monoculture √  Use of artificial fertilisers √  Poor veld management and burning √  Waterlogged soil conditions √  Overgrazing √  Removal of crop residue from the field √ (Any 3 x 1) (3) [35] TOTAL SECTION B: 105 GRAND TOTAL: 150 Copyright reserved Please turn over