Agricultural Sciences Grade 11 P1 2022 Memo (Eng)

Downloaded from hlayiso.com NATIONAL SENIOR CERTIFICATE GRADE 11 NOVEMBER 2022 AGRICULTURAL SCIENCES P1 MARKING GUIDELINE MARKS: 150 This marking guideline consists of 9 pages.

Downloaded from hlayiso.com 2 AGRICULTURAL SCIENCES P1 (EC/NOVEMBER 2022) SECTION A QUESTION 1 1.1 1.1.1 B ✓✓ 1.1.2 C ✓✓ 1.1.3 C ✓✓ 1.1.4 D ✓✓ 1.1.5 B ✓✓ 1.1.6 D ✓✓ 1.1.7 A ✓✓ 1.1.8 D ✓✓ 1.1.9 A ✓✓ 1.1.10 B ✓✓ (10 x 2) (20) 1.2 1.2.1 B only ✓✓ 1.2.2 None ✓✓ 1.2.3 Both A and B ✓✓ 1.2.4 A only ✓✓ 1.2.5 None ✓✓ (5 x 2) (10) 1.3 1.3.1 Sucrose ✓✓ 1.3.2 Catenate ✓✓ 1.3.3 Nitrogen ✓✓ 1.3.4 G-horizon ✓✓ 1.3.5 Nitrification ✓✓ (5 x 2) (10) 1.4 1.4.1 Ethanol ✓ 1.4.2 Structure ✓ 1.4.3 Cation adsorption ✓ 1.4.4 Hygroscopic ✓ 1.4.5 Denitrification ✓ (5 x 1) (5) TOTAL SECTION A: 45 Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/NOVEMBER 2022) AGRICULTURAL SCIENCES P1 3 SECTION B QUESTION 2: BASIC AGRICULTURAL CHEMISTRY 2.1 Inorganic compounds 2.1.1 Identification of substances (a) Substance B ✓ (b) Substance C ✓ (c) Substance A ✓ (3) 2.1.2 Indication of the role of water in SUBSTANCE A It serves as a solvent. ✓ (1) 2.1.3 Structural formula of SUBSTANCE C H N H H ✓✓ (2) 2.1.4 Justification of the components in SUBSTANCE A regarded as compound. They are formed from the combination ✓of two different chemical elements. ✓ (2) 2.2 Carbohydrates 2.2.1 Classification of the carbohydrate Monosaccharide ✓ (1) 2.2.2 Chemical formula of a monosaccharide C6H12O6 ✓✓ (2) 2.2.3 TWO important uses of monosaccharide • Provides energy ✓ • Work as flavour and sweetener in the human diet ✓ (2) 2.3 Fats 2.3.1 Classification of fat in food Food type A – Unsaturated fat ✓ Food type B – Saturated fat ✓ (2) 2.3.2 Identification of fat recommended to be included in a diet Unsaturated fat ✓ (1) 2.3.3 TWO reasons They are of plant origin ✓ and lower the blood cholesterol level ✓ (2) Copyright reserved Please turn over

Downloaded from hlayiso.com 4 AGRICULTURAL SCIENCES P1 (EC/NOVEMBER 2022) 2.3.4 Distinguishing between unsaturated and saturated fat (a) Reaction at room temperature – Unsaturated fat is liquid at room temperature ✓ and saturated fat is solid at room temperature. ✓ (2) (b) Bond between the carbon atoms – Unsaturated fat has one or more double bonds between carbon atoms ✓ and saturated fat has a single bond between carbon atoms. ✓ (2) 2.4 Protein 2.4.1 Building block of protein Amino acids ✓ (1) 2.4.2 Difference between simple and complex protein Simple proteins are proteins which when broken down yield only amino acids ✓ Complex proteins are simple proteins combined with some non- protein material. ✓ (2) 2.4.3 Reason for giving protein to: (a) Injured animals – To repair damaged tissues ✓ (1) (b) Newly born animals – To build up new cells and tissues/ growth ✓ (1) 2.5 Organic compounds 2.5.1 Labelling A – Propane ✓ B – C3H8 ✓ C – Hydroxyl/OH ✓ D– H H H C C OH ✓✓ H H E – Ethanoic / acetic ✓ (6) 2.5.2 Identification of a compound that can be used in alcoholic beverages Ethanol ✓ (1) 2.5.3 ONE importance of a compound A for rural communities It is used for heating. ✓ (1) [35] Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/NOVEMBER 2022) AGRICULTURAL SCIENCES P1 5 QUESTION 3: SOIL SCIENCE 3.1 Soil texture 3.1.1 Determining the texture (a) Clay ✓ (1) (b) Clay loam ✓ (1) 3.1.2 Comparing clay and sand (a) Tillability – Clay soil is hard to till ✓ and sandy soil is easy to till. ✓ (2) (b) Degree of plasticity – High plasticity in clay ✓ and low plasticity in sand. ✓ (2) 3.1.3 TWO reasons for a farmer to know the texture class • To know the type of crop to cultivate ✓ • To know when to cultivate and implement to use ✓ • To be able to assess the efficacy of fertilisers ✓ • To know the type of irrigation to use ✓ • To understand how soil will react better to temperature changes ✓ (Any 2 x 1) (2) 3.2 Soil water 3.2.1 Indication of the water movement demonstrated in the experiment Capillarity ✓ (1) 3.2.2 Reason Water moves upward ✓ (1) 3.2.3 Identification of the soil samples A – Clay ✓ C – Loam ✓ (2) 3.2.4 Way in which the water can be lost in sample B Percolation/seepage ✓ (1) 3.2.5 Method to reduce the water loss through percolation • Controlling the amount of irrigation water ✓ • Keeping soil under cover/mulching ✓ • Ploughing in organic material ✓ (Any 1 x 1) (1) Copyright reserved Please turn over

Downloaded from hlayiso.com 6 AGRICULTURAL SCIENCES P1 (EC/NOVEMBER 2022) 3.3 Soil air/gas 3.3.1 Prediction of the results of the experiment Container A – Seeds will germinate and grow ✓ Container B – No germination/growth will occur ✓ (2) 3.3.2 Explaining the reason for no germination in container B Absence of oxygen ✓responsible for seed germination due to waterlogged soil conditions ✓ (2) 3.3.3 Name of a gas accumulated in container A Carbon dioxide ✓ (1) 3.3.4 TWO reasons • Respiration of plant roots ✓ • Respiration of soil organisms ✓ (2) 3.4 Soil temperature 3.4.1 Deduction of the factor influencing soil temperature Soil depth ✓ (1) 3.4.2 Bar graph 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) ✓ • Bar graph ✓ • Accuracy ✓ (6) 3.4.3 Explaining the trend of temperature in soil at 5 cm deep There is a drastic increase of temperature during the day ✓ and it drops in the afternoon. ✓ (2) Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/NOVEMBER 2022) AGRICULTURAL SCIENCES P1 7 3.5 Bulk density 3.5.1 Calculation of bulk density Mass of dry soil (g) Bulk density = 3 ✓ Volume of dry soil (cm ) 680 g = 3 ✓ 80 cm = 8,5 g/cm3 ✓ (3) 3.5.2 Commenting on the suitability of soil for deep rooted crops Not suitable ✓ Reason Soil is compacted / has a high clay content. ✓ (2) [35] Copyright reserved Please turn over

Downloaded from hlayiso.com 8 AGRICULTURAL SCIENCES P1 (EC/NOVEMBER 2022) QUESTION 4: SOIL SCIENCE 4.1 Reproductive systems 4.1.1 Identification of soil profile (a) Soil profile C ✓ (b) Soil profile D ✓ (c) Soil profile B ✓ (3) 4.1.2 Name of the horizon (a) B – horizon ✓ (b) A – horizon ✓ (c) C – horizon ✓ (3) 4.1.3 TWO possible diagnostic horizons that may occur in soil profile C • Humic A ✓ • Vertic A ✓ • Melanic A ✓ • Orthic A ✓ (Any 2 x 1) (2) 4.2 Soil classification 4.2.1 Re-arrangement of steps in soil classification • Demarcate master horizons ✓ • Identify diagnostic horizons ✓ • Establishing soil form ✓ • Series characteristics are identified ✓ • Determine soil series ✓ (5 x 1) (5) 4.2.2 TWO methods used in South Africa to classify the soil • Soil form ✓ • Soil series/family ✓ (2) 4.3 Soil colloids 4.3.1 Identification of the type of colloid Inorganic colloid ✓ (1) 4.3.2 Differentiation between inorganic and organic colloids with regard to shape Inorganic colloids have a layered structure with flat platelets ✓ Organic colloids are structureless/ amorphous ✓ (2) 4.3.3 Condition of the colloid based on the cation adsorbed Colloid A – Acidic ✓ Colloid B – Neutral/sweet ✓ (2) 4.3.4 TWO factors causing colloidal condition in A/acidity • Carbon dioxide dissolving in water forming carbonic acid ✓ • Organic acids formed during decomposition process ✓ • Rain water/irrigation leaching basic ions ✓ • Fertilisation with ammonium sulphate ✓ (Any 2 x 1) (2) Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/NOVEMBER 2022) AGRICULTURAL SCIENCES P1 9 4.3.5 Detrimental effect of cation dominant on the colloid C on soil structure It has a deflocculating effect which causes the soil to be structureless ✓ (1) 4.3.6 TWO ways to correct the colloidal condition C physically • Scraping ✓ • Leaching salts from root zone through subsurface drain ✓ • Flushing ✓ (Any 2 x 1) (2) 4.4 Nutrient cycling 4.4.1 Identification of the letter A✓ (1) 4.4.2 TWO processes showing the return of carbon dioxide into the atmosphere • Respiration ✓ • Decomposition ✓ • Combustion ✓ (Any 2 x 1) (2) 4.4.3 THREE conditions necessary for the survival of micro-organisms • Soil fertility ✓ • Soil moisture ✓ • Soil temperature ✓ • Soil air ✓ • Soil pH ✓ • Light ✓ • Food and energy supply ✓ (Any 3 x 1) (3) 4.5 Symbiotic relationship 4.5.1 Name of micro-organism (a) Rhizobium ✓ (1) (b) Mycorrhiza ✓ (1) 4.5.2 Explanation of symbiotic relationship between legume crops and rhizobium bacteria Rhizobium bacteria fix atmospheric nitrogen for the legume crop ✓ and plants provide food for bacteria/house bacteria in the nodules formed in their roots. ✓ (2) [35] TOTAL SECTION B: 105 GRAND TOTAL: 100 Copyright reserved Please turn over