Geography Questions and Answers - Form 3 Opener Term 1 Exams 2022

GEOGRAPHY

Instructions:
Answer all the questions in the spaces provided.

Questions

1.            
   1. Give two dominant minerals in the outer core. (2 marks)
   2. Explain three reasons why the interior of the earth is very hot. (6 marks)
2.       
   1. Name three substances found in the atmosphere. (3 marks)
   2. State three characteristics of the troposphere layer of the atmosphere. (3 marks)
3.      
   1. What are metamorphic rocks? (2 marks)
   2. Explain how rocks influence the following:
      1. Agriculture (2 marks)
      2. Water storage. (2 marks)
4. The diagram below shows a type of a fault. Use it to answer the question (a)
   
   
   1. Name the parts marked X, Y and Z. (3 marks)
   2. Give three features formed by vertical earth movements. (3 marks)
   3. You are to carry out a field study on faulting along a section on the Great Rift Valley in Kenya.
      1. Give three advantages of using observation as a method of data collection. (3 marks)
      2. State two follow up activities for the field study. (2 marks)
5.            
   1. Describe how an explosion crater is formed. (5 marks)
   2. Explain three causes of Vulcanicity. (6 marks)
6.      
   1. Apart from savannah, give three other major types of natural vegetation in Kenya. (3 marks)
   2. Describe the characteristics of savannah vegetation. (6 marks)
7.    
   1. State two main reasons why forest reserves were created in Kenya. (2 marks)
   2. Give three differences between softwood forests in Kenya with those in Canada. (6 marks)
8. The table below shows major coffee producing countries in Africa in the year 2010.
   

   COUNTRY	PRODUCTION IN MILLION BAGS
   Ivory Coast	2.20
   Kenya	0.85
   Ethiopia	7.45
   Tanzania	0.92
   Uganda	3.10

   
   
   1. Calculate the percentage of the lowest coffee producer based on the information on the table. (2 marks)
   2. Using a radius of 5cm, draw a pie chart to present the information in the table. (9 marks)

Marking Scheme

1.            
   1. Give two dominant minerals in the outer core. (2 marks)
      • Iron√
      • Nickel√
        
        
   2. Explain three reasons why the interior of the earth is very hot. (6 marks)
      • The earth still retains the original heat it had before cooling. During formation, the outer parts cooled faster than the inner parts thus retaining the heat at the centre. √√
      • Due to the weight of the overlying materials on the crust which exerts a lot of pressure towards the centre of the earth. This generates a lot of heat in the interior. √√
      • Breakdown of radioactive elements especially at the mantle region. This releases a lot of heat energy which is trapped in the interior. √√
2.                
   1. Name two substances found in the atmosphere. (2 marks)
      • Gases/air√
      • Water vapour√
      • Dust particles
      • Smoke particles√
      • Clouds √
        
        
   2. State three characteristics of the troposphere layer of the atmosphere. (3 marks)
      • It is the lowest layer of the atmosphere. √
      • It extends to about 10 – 12 km above the surface. √
      • It experiences a normal lapse rate/temperature decreases with increase in height. √
      • It contains 90% of the total moisture in the atmosphere. √
      • It contains 75% of the air in the atmosphere. √
        
        
3.             
   1. What are metamorphic rocks? (2 marks)
      • These are rocks formed when original igneous or sedimentary rocks have been altered by intense heat, pressure or both.
        
        
   2. Explain how rocks influence the following:
      1. Agriculture (2 marks)
         • Some rocks especially volcanic undergo weathering over long periods of time to form very rich and fertile soils that support a wide variety of crops. √√
           
           
      2. Water storage. (2 marks)
         • Permeable rocks where underlain by impermeable rocks hold and store ground water as aquifers. Such water forms vital springs or is drawn through boreholes for domestic, industrial or irrigation purposes. √√
           
           
4. The diagram below shows a type of a fault. Use it to answer the question (a)
   1. Name the parts marked X, Y and Z. (3 marks)
      • X – Escarpment/Fault scarp√
      • Y – Throw√
      • Z - Hade√
        
        
   2. Give three features formed by vertical earth movements. (3 marks)
      • Basins/depressions√
      • Fault scarps/escarpments √
      • Horsts/Tilt blocks/Block mountains√
      • Rift valleys √
      • Submerged coasts√
      • Emerged coasts. √
      • Raised cliffs√
        
        
   3. You are to carry out a field study on faulting along a section on the Great Rift Valley in Kenya.
      1. Give three advantages of using observation as a method of data collection.
         • Observation gives first hand data. √
         • It is an easy method of collecting data. √
         • A lot of data can be collected in one place. √
         • New knowledge can be learnt through observation. √ (3 marks)
           
           
      2. State two follow up activities for the field study. (2 marks)
         • Writing a report on data collected. √
         • Analyzing and classifying the data collected√
         • Displaying processed photographs taken during the study. √
         • Conducting group discussions based on data collected. √
         • Giving a lecture to other students. √
           
           
5.                   
   1. Describe how an explosion crater is formed. (5 marks)
      • In some volcanic active zones, ground water and some gases may come in contact with hot magma. √
      • The water and gases are intensely heated thus expand.
      • This builds up intense pressure below the surface. √
      • The pressure may move along lines of weakness towards the earth surface. √
      • When this pressure is released near the ground level, a violent explosion occurs. √
      • *The explosion blows out a large depression at the ground level called an explosion crater. √
      • NB. *The last point with the must be given to score maximum marks
        
        
   2. Explain three causes of Vulcanicity. (6 marks)
      • High temperatures in the interior of the earth which heats materials into molten form (magma).√√
      • High pressure in the interior of the earth mainly due to earth movements which pushes igneous materials towards the crust. √√
      • Faulting process which creates lines of weakness such as cracks, fissures and vents through which hot materials pass towards the crust/to the surface. √√
      • Underground water which is heated by hot rocks to form steam which leads t the formation of hot springs, geysers and fumaroles. √√
6.                     
   1. Apart from savannah, give three other major types of natural vegetation in Kenya. (3 marks)
      • Forests√
      • Arid and semi-arid vegetation√
      • Heath and moorland√
      • Swamp vegetation√
        
        
   2. Describe the characteristics of savannah vegetation. (6 marks)Savannah consists of a mixture of trees and grass. √
      • Trees are of medium height.(10 – 13 metres) √
      • The dominant tree species is acacia. √
      • Most of the tree species are deciduous thus shed leaves during the dry season. √
      • Most trees have needle like leaves to reduce water loss. √
      • Tree crowns are umbrella shaped to provide shade so as to reduce evaporation around the trunk and roots. √
      • In drier areas, trees are shorter and further apart. √In dry areas, baobab and bottle brush trees are evident. √
      • In wetter areas, grass species are tall and green. √
      • In drier areas, the grass is short, tough and dry. √
      • In wet areas, grass species dominate under growths between trees. √
        
        
7.                 
   1. State two main reasons why forest reserves were created in Kenya. (2 marks)
      • To control soil erosion. √
      • To protect water catchment areas. √
        
        
   2. Give three differences between softwood forests in Kenya with those in Canada. (6 marks)
      • In Kenya, there are both indigenous and exotic tree species whereas in Canada, all tree species are indigenous. √√
      • In Kenya, softwoods are mainly planted while in Canada, softwoods are mainly natural. √
      • In Kenya, softwood tree species mature faster due to warm conditions/moderate to high temperatures whereas in Canada, softwoods take a longer duration to mature due to cold winters. √√
      • In Kenya, softwoods are found in the Kenya highlands while in Canada, softwoods are found in both highlands and lowlands. √√
      • In Kenya, softwood forests cover a very small percentage of total Kenya’s area whereas in Canada, softwoods cover a large percentage of Canada’s total area. √√
      • In Kenya, there are fewer varieties of softwood tree species whereas in Canada, there is a wide variety of softwood tree species. √√
        
        
8. The table below shows major coffee producing countries in Africa in the year 2010.
   1. Calculate the percentage of the lowest coffee producer based on the information on the table. (3 marks)
      • Total 2.20 + 0.85 + 7.45 + 0.92 + 3.10 = 14.52 million bags √
        Lowest coffee producer: Kenya
        0.85 Million Bags X 100% = 5.85% √√
        14.52 Million Bags
        
        
   2. Using a radius of 5cm, draw a pie chart to present the information in the table. (9 marks)
      • Calculations
        Ethiopia: 7.45 Million Bags X 3600 = 184.70 √
        14.52 Million Bags
        Uganda: 3.10 Million Bags X 3600 = 76.90 √
        14.52 Million Bag
        Ivory Coast: 2.20 Million Bags X 3600 = 54.50 √
        14.52 Million Bags
        Tanzania: 0.92 Million Bags X 3600 = 22.80 √
        14.52 Million Bags
        Kenya: 0.85 Million Bags X 3600 = 21.10 √
        14.52 Million Bags
        
      • Calculations: 5 marks
        Sectors 3 marks
        Title 1 mark
        TOTAL 9 marks