Agricultural Sciences Grade 11 P1 2015 QP (Eng)

Downloaded from hlayiso.com NATIONAL SENIOR CERTIFICATE GRADE 11 NOVEMBER 2015 AGRICULTURAL SCIENCES P1 MARKS: 150 TIME: 2½ hours *IAGRSE1* This question paper consists of 13 pages.

Downloaded from hlayiso.com 2 AGRICULTURAL SCIENCES P1 (EC/NOVEMBER 2015) INSTRUCTIONS AND INFORMATION 1. Answer ALL the questions in the ANSWER BOOK. 2. Start EACH question on a NEW page. 3. Read ALL the questions correctly and answer only what is asked. 4. Number the answers correctly according to the numbering system used in this question paper. 5. Non-programmable calculators may be used. 6. Show ALL your calculations, including units and formula, where applicable. 7. Write neatly and legibly. Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/NOVEMBER 2015) AGRICULTURAL SCIENCES P1 3 SECTION A QUESTION 1 1.1 Various options are provided as possible answers to the following questions. Choose the correct answer and write only the letter (A–D) next to the question number (1.1.1–1.1.10) in the ANSWER BOOK, for example 1.1.11 A. 1.1.1 The group of elements usually occurring in proteins are ... A C, P, Ca, O and Mg. B C, H, O, N and P. C S, C, N, O and H. D Mg, K, H, Ca and Zn. 1.1.2 The statement below does NOT apply to the following group of elements: Li Na K Rb Cs Fr A They are alkali metals. B They belong to group 1A and has one valence electron. C They are non-reactive. D They are highly reactive. 1.1.3 The structure below represents the structural formula of an organic compound. H H H C C H H H (i) It is a colourless, odourless gas. (ii) It is used for ethylene production. (iii) It can be described as a hydrocarbon. (iv) It is an important alcohol in nature, Choose the correct combination: A (i), (iii), and (iv) B (ii), (iii) and (iv) C (i), (ii) and (iv) D (i), (ii) and (iii) 1.1.4 The texture has an effect on the ... A growth rate of plants. B water holding capacity of soil. C organic content of soil. D structure of soil. Copyright reserved Please turn over

Downloaded from hlayiso.com 4 AGRICULTURAL SCIENCES P1 (EC/NOVEMBER 2015) 1.1.5 The following statement refers to bulk density: A The more the pore space, the lower the bulk density. B The higher the organic matter in soil, the higher the bulk density. C The lesser the pore space, the higher the bulk density. D Soil with a high clay content have a lowered bulk density. 1.1.6 The diagram below shows a factor influencing soil temperature. Sun’s rays B C A D A Seeds germinate faster in soil represented by letter B. B Sun rays strike the soil obliquely at letter D. C The soil at point B receives greater number of sun rays. D When sun rays strike the soil at point D, they will be reflected back and seeds will germinate faster. 1.1.7 The schematic representation below demonstrate the following: Na + CaSO4 Ca2+ + Na2SO4 A The increase of the soil pH B Improving soil fertility C Reclamation of brackish soil D Correcting soil acidity 1.1.8 The binomial soil classification system contains a broad and more general level regarding (a) ... and a lower and more specific level regarding (b) ... (a) (b) A soil form soil family B soil series soil form C soil form soil horizon D soil profile soil horizon Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/NOVEMBER 2015) AGRICULTURAL SCIENCES P1 5 1.1.9 The physical influence of organic matter on soil is ... A more nutrients become available. B a decrease in the swelling of clay soil when wet. C an increase in the number of micro-organisms. D that the soil become fertile due to high cation absorption cacapity. 1.1.10 The G horizon is an indication of ... A gleying condition. B absence of organic matter. C oxidation process. D accumulation of iron oxides. (10 x 2) (20) 1.2 Indicate whether each of the descriptions in COLUMN B applied to A ONLY, B ONLY, BOTH A and B or NONE of the items in COLUMN A Write A ONLY, B ONLY, BOTH A and B or NONE next to the question number (1.2.1–1.2.5) in the ANSWER BOOK, for example 1.2.6 B only. COLUMN A COLUMN B 1.2.1 A Atomic number No of protons and neutrons B Atomic mass 1.2.2 A Carbon An element which is able to catenate B Hydrogen 1.2.3 A Nitrification Reduction of nitrates under anaerobic conditions B Denitrification 1.2.4 A Hygroscopic The type of soil water that forms a thin film B Adhesion around soil particles 1.2.5 A Vertic A Diagnostic horizon with a mass of cemented B Humic A mottles (5 x 2) (10) 1.3 Give ONE word/term for each of the following descriptions. Write only the word/term next to the question number (1.3.1–1.3.5) in the ANSWER BOOK. 1.3.1 The smallest particle of a substance which can exist independently and still retain the properties of that substance. 1.3.2 The conversion of insoluble inorganic forms of nutrients to soluble forms by the action of bacteria. 1.3.3 The point in soil where all pore spaces are completely filled with water. 1.3.4 The concentration of nutrients and certain chemical compounds in only one part of the soil and absent somewhere else. 1.3.5 The soil structure that has thin peds which are oriented in a horizontal direction. (5 x 2) (10) Copyright reserved Please turn over

Downloaded from hlayiso.com 6 AGRICULTURAL SCIENCES P1 (EC/NOVEMBER 2015) 1.4 Change the underlined word(s) in each of the following statements to make them TRUE. Write only the correct word(s) next to the question number (1.4.1–1.4.5) in the ANSWER BOOK. 1.4.1 Dextrin is an example of a disaccharide. 1.4.2 Isotopes are organic compounds that have the same molecular formulae but different arrangement of atoms. 1.4.3 Hydrolysis is the transfer of an amino group from one chemical compound to another. 1.4.4 A homogeneous soil colour occurs when there is a mixture of soil material or mineral composition. 1.4.5 Cation adsorption is the sum total of the exchangeable cations in the soil. (5 x 1) (5) TOTAL SECTION A: 45 Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/NOVEMBER 2015) AGRICULTURAL SCIENCES P1 7 SECTION B Start this question on a NEW page. QUESTION 2: BASIC AGRICULTURAL CHEMISTRY 2.1 Organic compounds are very important in our daily lives. They are in the food we eat and clothes we wear. The chemical properties of organic compounds is determined by their functional group. The structural formulas below are the compounds playing a role in our lives. A. B. H H H H H H C C C H H C C OH OH OH OH H H C. D. H O H H H H C C OH H C C C H H H H H 2.1.1 Indicate the letter of a compound that matches each of the following descriptions: (a) Formed by the fermentation process (1) (b) It is also known as acetic (1) (c) It is formed when the structure represented by letter B reacts with structure in C (1) (d) Can be used for heating in rural homes with no electricity (1) 2.1.2 Explain the impact of a compound labelled D on the environment. (2) 2.1.3 Describe the benefit of using a compound labelled C as a source of energy for cars instead of petrol. (2) 2.1.4 Indicate the functional group of compounds labelled B and C. (2) Copyright reserved Please turn over

Downloaded from hlayiso.com 8 AGRICULTURAL SCIENCES P1 (EC/NOVEMBER 2015) 2.2 Salt forms part of a diet for animals and human beings. It is an important part of the fluid electrolytes of humans and other living organisms. 2.2.1 Give the chemical name and formula for salt. (2) 2.2.2 Indicate the bond that exist between the elements forming salt. (1) 2.2.3 During ancient times, salt was a valuable mineral in people's daily lives. Validate this statement by explaining THREE uses of salt during this era. (3) 2.3 Acids and base play a vital role in agriculture. 2.3.1 Tabulate TWO differences between acid solution and base solution. (4) 2.3.2 If an acid solution is mixed with an alkaline solution, a chemical reaction takes place. Give the name of this reaction. (1) 2.3.3 State TWO products of the chemical reaction in QUESTION 2.3.2 above. (2) 2.4 Analyse the structure below and answer the questions based on it. R H O B N C C A H H OH 2.4.1 Identify the structure above. (1) 2.4.2 Indicate the letter (A or B) that gives the structure in QUESTION 2.4.1 the following: (a) Basic property (1) (b) Acidic property (1) 2.4.3 Two or more of the structures mentioned in QUESTION 2.4.1 above, can be joined together to form a polymer. Provide the name of this reaction. (1) 2.4.4 The polymer formed from joining two or more of the structures above plays a vital role in the body of an animal. Justify this statement with THREE reasons. (3) Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/NOVEMBER 2015) AGRICULTURAL SCIENCES P1 9 2.5 Carbohydrates are organic molecules which acts as energy suppliers in the food of animals. Some carbohydrates are very large and complex while others are simple. Different foods supply different types of carbohydrates. Indicate the example of a monosaccharide or disaccharide or polysaccharide supplied by each of the following food and plant source: 2.5.1 Fruits (1) 2.5.2 Milk (1) 2.5.3 Cane sugar (1) 2.5.4 Wood (1) 2.5.5 Plant cell (1) [35] Copyright reserved Please turn over

Downloaded from hlayiso.com 10 AGRICULTURAL SCIENCES P1 (EC/NOVEMBER 2015) Start this question on a NEW page. QUESTION 3: SOIL SCIENCE 3.1 The table below shows the physical characteristics of soil on two wheat farms. Physical soil characteristics Farm A Farm B Structure Crumb Blocky Soil fraction (mm) 2,00 – 0,50 Less than 0,002 Depth (mm) 950 450 Colour Light Grey 3.1.1 Indicate the farm which is likely to be easily saturated with water. (1) 3.1.2 Give TWO reasons for the answer in QUESTION 3.1.1 from the table. (2) 3.1.3 Deduce the farm which is likely to have a higher wheat yield. (1) 3.1.4 Justify by explaining TWO characteristics from the table which can result in higher yield. (4) 3.1.5 State THREE benefits of the structure in farm A. (3) 3.2 Pore space of soil is important because soil pores are filled with water and gases which are important for plant growth. The percentage of the total pore space is determined by various factors. 3.2.1 Describe the influence of the following factors on the total pore space: (a) Soil depth (1) (b) Soil cultivation (1) 3.2.2 Name TWO other factors that may have an influence on the total pore space. (2) 3.3 The colour of the soil can give much information to the farmer or to the soil scientist provided it is interpreted correctly. Indicate the colour of the soil that is likely to occur under the following climatic conditions: 3.3.1 Cool temperate regions (1) 3.3.2 Humid regions (1) 3.3.3 Dry conditions (1) Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/NOVEMBER 2015) AGRICULTURAL SCIENCES P1 11 3.4 A farmer has a small piece of land for growing crops. Because of the different moisture conditions, the land was divided into two, one piece for vegetables and another piece for maize. The farmer cleared the land in preparation for planting. Soon after the preparation, there was heavy rain for 2 days and the land was saturated with water. Moisture content of both pieces was measured for a period of 10 days. The results are shown in the table below. DAY 1 2 3 4 5 6 7 8 9 10 Moisture content of 20 13 9 7 5 4 3 2 1 1 land for maize (%) Moisture content of 20 18 16 14 13 12 10 7 6 5 land for vegetables (%) 3.4.1 Plot a line graph of the moisture content for two pieces of land against time in days. (6) 3.4.2 Suggest THREE ways to limit the loss of water in land used for maize. (3) 3.5 The following diagram illustrates the factor that influences soil temperature. 3.5.1 Indicate the factor that influences temperature as illustrated above. (1) 3.5.2 Explain the reason for each of the following soil temperature: (a) Land will be warmer for a long time under moist and cloudy condition. (2) (b) Low temperature in light coloured soils as compared to dark soils. (2) 3.5.3 State THREE influences of soil temperature on biological processes taking place in soil. (3) [35] Copyright reserved Please turn over

Downloaded from hlayiso.com 12 AGRICULTURAL SCIENCES P1 (EC/NOVEMBER 2015) Start this question on a NEW page. QUESTION 4: SOIL SCIENCE 4.1 The horizontal layers of the soil are the result of environmental factors, particularly climatic factors and have developed over the period of time. One process occurs after the other until all horizons are visible. 4.1.1 Re-arrange the following processes showing the development of master horizons over time.  Through the process of littering, plants will drop leaves and twigs onto soil to form the O-horizon  Small pieces of rocks formed C-horizon  Weathered rock undergo chemical weathering to form soil which become the medium for vegetation to grow  A-horizon is formed  The rock expands and contract leading to physical weathering  Micro-organisms convert organic debris on the soil through the process of humification (6) 4.1.2 Suggest the condition leading to the development of an E-horizon. (1) 4.1.3 If you are asked to dig a profile test hole of a well-developed soil, predict THREE characteristics that may be revealed to show that you are in a B-horizon. (3) 4.2 Soil classification is the systematic arrangement of soil into classes or categories based on their most important properties and giving names to the unique arrangement or combination of these classes. 4.2.1 Determine the procedure for soil classification in a sequential order. (5) 4.2.2 Outline TWO reasons why soil is classified. (2) Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/NOVEMBER 2015) AGRICULTURAL SCIENCES P1 13 4.3 Soil reaction influences not only the nutrient content of the soil, but also the structure, drainage and microbial composition of the soil. All these aspects of soil have a direct impact on crop production. The pH of the soil is determined by the relative concentration of adsorbed cations on soil colloids. The most common adsorbed cations include the following: H+ , Ca+2 , K+ , Al+3 , Mg+2 and Na+ 4.3.1 From the list of ions above, select TWO ( in each case), that influences the soil reactions below: (a) Alkalinity (2) (b) Acidity (2) (c) Neutrality (2) 4.3.2 Indicate TWO negative impacts of soil dominated by Al+3 on crop production. (2) 4.3.3 Suggest the method to control the problem stated in QUESTION 4.3.2 above. (1) 4.4 The schematic representation below illustrates the recycling of carbon dioxide from the atmosphere to the living organisms and back again. 4.4.1 Provide labels for the processes numbered 1, 3, 4, 5 and 6. (5) 4.4.2 Name TWO important soil micro-organisms that play a role during the process labelled 5. (2) 4.4.3 State TWO requirements of the organisms in QUESTION 4.4.2 above. (2) [35] TOTAL SECTION B: 105 GRAND TOTAL: 150 Copyright reserved Please turn over

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