Agricultural Sciences Grade 11 P1 2014 Memo (Eng)

Downloaded from hlayiso.com NATIONAL SENIOR CERTIFICATE GRADE 11 NOVEMBER 2014 AGRICULTURAL SCIENCES P1 MEMORANDUM MARKS: 150 This memorandum consists of 8 pages.

Downloaded from hlayiso.com 2 AGRICULTURAL SCIENCES P1 (NOVEMBER 2014) SECTION A QUESTION 1 1.1 1.1.1 B √√ 1.1.2 A √√ 1.1.3 D √√ 1.1.4 D √√ 1.1.5 C √√ 1.1.6 A √√ 1.1.7 D √√ 1.1.8 C √√ 1.1.9 B √√ 1.1.10 D √√ (10 x 2) (20) 1.2 1.2.1 B √√ 1.2.2 Both A and B √√ 1.2.3 None √√ 1.2.4 A √√ 1.2.5 B √√ (5 x 2) (10) 1.3 1.3.1 Periodic table √√ 1.3.2 Reserve acidity √√ 1.3.3 Inaccessible/unavailable √√ 1.3.4 Nitrogen √√ 1.3.5 Plasticity √√ (5 x 2) (10) 1.4 1.4.1 Platy √ 1.4.2 cation exchange capacity √ 1.4.3 Solution √ 1.4.4 Halogen √ 1.4.5 Isotope √ (5 x 1) (5) TOTAL SECTION A: 45 Copyright reserved Please turn over

Downloaded from hlayiso.com (NOVEMBER 2014) AGRICULTURAL SCIENCES P1 3 SECTION B QUESTION 2: BASIC CHEMISTRY 2.1 2.1.1 Functional group of ethanol Hydroxyl group √ (1) 2.1.2 Structural formula of ethanol H H H C √ C √ OH √ H H (3) 2.1.3 Advantages of ethanol (a) Environmentally – fewer greenhouse gases. √ (1) (b) Economically – it is produced with fewer costs. √ (1) 2.1.4 Name and categorise carbohydrates Cellulose √ – polysaccharide √ (2) 2.2 2.2.1 Identifying organic compounds A – Galactose √ B – Fructose √ (2) 2.2.2 A – Aldo ring √ B – Keto ring √ (2) 2.2.3 Difference between glucose and galactose They differ because the position of OH on the 4th carbon atom is not the same. √√ (2) 2.3 Position of polysacchides 2.3.1 Lignin – wood √ (1) 2.3.2 Starch –stored in the leaves, roots and stem of plants. √ (1) 2.3.3 Glycogen – liver and muscles of an animal. √ (1) 2.4 THREE indigenous foods as a source of starch  Potatoes √  Rice √  Samp/maize √  Wheat √  Oats √  Sorghum √  Bread (barley) √ (Any 3 x 1) (3) Copyright reserved Please turn over

Downloaded from hlayiso.com 4 AGRICULTURAL SCIENCES P1 (NOVEMBER 2014) 2.5 2.5.1 Bar graph to compare protein, fat and carbohydrate in oats porridge and peanut butter The amount of carbohydrate, protein and fat in oats porridge and peanut butter 60 56 50 Amount in g/100 g 50 40 30 24 23 carbohydrates 20 Protein 12 9 10 Fats 0 Oats Peanut porridge butter Type of food Checklist for marking a graph Criteria Mark 1. Bar graph 1√ 2. X-axis labelled 1√ 3. Y-axis labelled 1√ 4. Points correctly plotted 1√ 5. Correct heading 1√ 6. Key 1√ (6) 2.5.2 Food containing saturated fat Tuna fish √ (1) 2.5.3 Reason It is of animal origin. √√ (2) 2.6 2.6.1 Identification of a chemical reaction Neutralisation √ (1) 2.6.2 The reaction takes place between the acid and a base. √ (1) 2.6.3 TWO chemical bonds involved and examples Ionic bond √ example – HCL / KOH / KCl √ Covalent bond √ example – H2O √ (4) [35] Copyright reserved Please turn over

Downloaded from hlayiso.com (NOVEMBER 2014) AGRICULTURAL SCIENCES P1 5 QUESTION 3: SOIL SCIENCE 3.1 3.1.1 Identification of a compacted soil B√ (1) 3.1.2 TWO visible signs of compaction  Presence of micro pores √  Poor root development √ (2) 3.1.3 TWO ways to improve compaction  Adding organic matter. √  Minimum tillage / less soil cultivation. √  Mulching / plant cover. √  Avoid tillage when soil is wet. √ (Any 2 x 1) (2) 3.1.4 THREE advantages of soil structure A  Easy root penetration √  Increased water infiltration √  Better water holding capacity √  Reduced soil crusting √  Reduced soil erosion √ (Any 3 x 1) (3) 3.2 3.2.1 Texture classes A – Loam √ (1) B – Clay √ (1) C – Sand √ (1) 3.2.2 Characteristics of textures (i) C √ (1) (ii) B √ (1) (iii) A √ (1) 3.3 Indication of air and moisture in red and grey colour 3.3.1 Enough air in red soil √ and absence of air in grey soil. √ (2) 3.3.2 Low moisture in red √ and high moisture in grey soil. √ (2) 3.4 3.4.1 Forces that attract water molecules to soil particles A – Adhesion forces √ B – Cohesion forces √ C – Gravitational forces √ (3) 3.4.2 Reason for drainage of water at C The distance between the water molecules and soil particles is high and √ Earth gravity causes water to flow away as it is greater than cohesion force. √ (2) 3.5 Soil water balance equation Changes in soil water √ = inputs of water √ –losses of water √ (3) Copyright reserved Please turn over

Downloaded from hlayiso.com 6 AGRICULTURAL SCIENCES P1 (NOVEMBER 2014) 3.6 3.6.1 Calculation of bulk density mass of dry soil g BD = olume of dry soil cm g = cm = 2,32 g/cm3 √ (3) 3.6.2  High bulk density √  Not suitable for root crop √ (2) 3.7 3.7.1 Influence of temperature on chemical processes The higher the temperature, the faster the chemical reactions. √ This leads to the release of plant nutrients. √ (2) 3.7.2 TWO ways to manipulate soil temperature  Mulching √  Clear plastic cover √  Shading √  Irrigation √  Deep or shallow ploughing √ (Any 2 x 1) (2) [35] Copyright reserved Please turn over

Downloaded from hlayiso.com (NOVEMBER 2014) AGRICULTURAL SCIENCES P1 7 QUESTION 4: SOIL SCIENCE 4.1 Characteristics of soil profiles 4.1.1 C√ (1) 4.1.2 B√ (1) 4.1.3 D√ (1) 4.1.4 A√ (1) 4.2 4.2.1 Identification of master horizons A horizon √ B horizon √ (2) 4.2.2 TWO series characteristics  Dark soil colour √  Blocky structure √ (2) 4.2.3 TWO characteristics of vertic A  Strongly developed blocky structure √  Sticky when wet √  May have large cracks √  High plastic index √  May have slicken sides √  Dark coloured √ (Any 2 x 1) (2) 4.3 4.3.1 Identification of a colloidal condition of the colloids A – Acidic √ B – Neutral √ C – Alkaline √ (3) 4.3.2 TWO factors influencing acidity  Application of nitrogen fertiliser √  Acid rain √  Oxidation of sulphates √  Carbonic acids √ (Any 2 x 1) (2) 4.3.3 Exchange reaction of reclamation process √ H √ CaCO3 √ Ca + H2CO2 √ H (3) Copyright reserved Please turn over

Downloaded from hlayiso.com 8 AGRICULTURAL SCIENCES P1 (NOVEMBER 2014) 4.4 Comparison of saline and sodic soils Characteristics Sodic soil Saline soil 4.4.1 Dominant salts Na √ Ca and Mg √ (2) 4.4.2 Surface appearance Black crust √ White crust √ (2) 4.4.3 Corrective measures Apply gypsum √ Over irrigation √ (2) 4.5 Fertility levels of vermiculite and kaolinite 4.5.1 Vermiculite – high fertility because of high negative charges √ which adsorb high amounts of cation. √ (2) 4.5.2 Kaolinite – Infertile because of low adsorption of cations √ and less negative charge. √ (2) 4.6 4.6.1 THREE practices causing the decline of organic matter  Soil texture √  Tillage of soil √  Type of vegetation √  Use of artificial fertiliser √  Cultivation of natural veld √  Poor veld management and burning √ (Any 3 x 1) (3) 4.6.2 Influence of organic matter on biological properties It provides nutrients for micro-organisms √ which stimulates their growth. √ (2) 4.6.3 TWO ways that plants benefit from a mycorrhiza relationship  Plant roots absorb more phosphorus. √  Helps roots to absorb zinc, copper and other nutrients. √  Protects plants against diseases. √ (Any 2 x 1) (2) [35] TOTAL SECTION B: 105 GRAND TOTAL: 150 Copyright reserved Please turn over