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

Questions

1.        
   1. What is a natural satellite? (2 mks)
   2. Give two dates of the year when equinox occurs. (2 mks)
2.      
   1. Differentiate between natural vegetation and secondary vegetation. (2 mks)
   2. State three ways in which rainfall influences the distribution of natural vegetation in Kenya. (3 mks)
3.    
   1. List two land masses that formed from Gondwana land according to the continental drift theory. (2 mks)
   2. State three effects of earth movements on the landscape. (3 mks)
4.     
   1. Give four agents of weathering. (4 mks)
   2. State how topography influences weathering of rocks. (2 mks)
5. Give five characteristics of cumulative bar graphs. (5 mks)
6.        
   1. Explain the following processes of weathering
      1. Slaking (3 mks)
      2. Hydration. (3 mks)
   2. Explain how the following physical factors enhance movement of materials along a slope due to gravity:-
      1. Angle of the slope (2 mks)
      2. Vegetation cover (2 mks)
   3.    
      1. List two types of mass wasting. (2 mks)
      2. You are required to carry out a field work study on weathering in an area near you. Outline the ways in which you will prepare before the study. (9 mks)
7. State four factors that influence the occurrence of surface run-off. (4 mks)

Marking Scheme

1.          
   1. What is a natural satellite? (2 mks)
      • Heavenly body that revolves/orbits round a planet.
   2. Give two dates of the year when equinox occurs. (2 mks)
      • 21st March
      • 23rd September.
2.                  
   1. Differentiate between natural vegetation and secondary vegetation. (2 mks)
      • Natural vegetation refers to plant cover that grows in the wild/on its own without influence by people or animals, whereas Secondary vegetation refers to plant cover that grows on its own after original vegetation has been interfered with by people or animals.
   2. State three ways in which rainfall influences the distribution of natural vegetation in Kenya. (3 mks)
      • Areas that receive high rainfall tend to have luxuriant vegetation/forests.
      • Areas receiving moderate rainfall mainly have grasslands.
      • Areas that receive low rainfall have scrub vegetation.
        
        
3.                
   1. List two land masses that formed from Gondwa naland according to the continental drift theory. (2 mks)
      • Africa
      • Australia
      • India
      • Antarctica
      • South America.
   2. State three effects of earth movements on the landscape. (3 mks)
      • Causes folding and related features
      • Causes occurrence of vulcanicity and related features.
      • Occurrence of earthquakes in some areas
      • Development of faults.
      • Vertical movements result in Basins/Raised cliffs/Fault blocks/Submerged
      • Coasts/Raised beaches.
        
        
4.             
   1. Give four agents of weathering. (4 mks)
      • Heat
      • Water
      • AirDissolved substances/Acids
      • Plants and animals.
   2. State how topography influences weathering of rocks. (2 mks)
      • Weathering is faster on steep slopes because the rocks are exposed since the weathered materials are removed faster by gravity. On gentle slopes and flat areas the rate of weathering is slow because weathered materials cover rocks beneath.
        
        
5. Give five characteristics of cumulative bar graphs. (5 mks)
   • Made up of horizontal/vertical bars
   • Length of the bars represents the total values
   • Drawn according to scale
   • Bars are subdivided into component parts
   • Have different shadings representing various components/items.
   • Must have an information title.
6.          
   1. Explain the following processes of weathering:
      1. Slaking (3 mks)
         • Effective in regions experiencing a definite wet and dry season.
         • Common in rocks containing clay.
         • Clay absorbs moisture when in rains which makes it swell.
         • When the dry season comes, the particles loose the water, making them shrink.\
         • Alternate swelling and shrinking makes the particles to detach themselves, falling away.
         • The rocks thus disintegrate.
      2. Hydration. (3 mks)
         • Certain rock minerals absorb water and expand.
         • The minerals are hygroscopic.
         • The expansion causes the rock to undergo internal stress.
         • The rock eventually disintegrates.
           
           
   2. Explain how the following physical factors enhance movement of materials along a slope due to gravity:-
      1. Angle of the slope (2 mks)
         • The steeper the slope the faster the rate of movement.
      2. Vegetation cover (2 mks)
         • Vegetation cover.
         • Bare surfaces are more likely to experience mass wasting because there is no vegetation to bind the materials together.
   3.        
      1. List two types of mass wasting. (2 mks)
         • Earthflows
         • Mudflows
         • Landslides
         • Rainwash/Downwash
         • Soil creep/Talus creep/Rock creep/Solifluction
      2. You are required to carry out a field work study on weathering in an area near you.
         • Outline the ways in which you will prepare before the study. (9 mks)
         • Seek permission from the relevant authorities
         • Conduct a pre-visit
         • Hold class discussion on the topic
         • Divide the class into convenient groups
         • Prepare methods of data collection/recording
         • State the objectives of the study
         • Formulate the hypothesis of the study
         • Prepare a working schedule
         • Select the relevant tools/equipment for the study.
           
           
7. State four factors that influence the occurrence of surface run-off. (4 mks)
   • Amount of water/nature of rainfall
   • Gradient of the land
   • Nature of the rocks/soil
   • Water table/level of saturation
   • Vegetation cover.