GEOGRAPHY - FORM 3 END TERM 1 EXAMS 2020

SECTION A.

Answer all the questions in this section.

1.  
   1.  
      1. Define the term atmosphere.                                                                           (2mks)
      2. State three components suspended in free atmosphere.                                     (3mks)
   2.  
      1. Apart from the troposphere, name two other main zones of the atmosphere.       (2mks)
      2. Give THREE characteristics of the troposphere.                                                  (3mks)
2.  
   1.  Differentiate between primary data and secondary data.                                            (2mks)
   2. Apart from conducting interview state three other methods of collecting statistical data.  (3mks)
3.  
   1. Draw a simple fold. On it indicate the following
      1. Crest
      2. Trough
      3. Limb
   2. State two negative effects of folding on human activities.                                            (2mks)
4.  
   1. Below is a diagram showing parts associated with faulting. Name the parts U, V, W.       (3mks)
      
   2. State two forces which cause faulting.                                                                        (2mks
5.  
   1. Apart from biological weathering, name two other types of weathering.                         (2mks)
   2. State three ways in which plants influence weathering.                                                (3mks)

SECTION B

ANSWER QUESTIONS 6 AND ANY OTHER TWO QUESTIONS FROM THIS SECTION

6. Study the map of Oyugis 1:50,000 (sheet 130/1) provided and answer the following questions.
   1.  
      1. State the types of scale used in the map.                                                        (2mks)
      2. Express the scale used in the map in statement.                                              (1mk)
      3. Measure the length of the loose surface road from grid square 6731 to grid reference 77 0186. Give your answer in kilometers.  (2mks)
      4. Calculate the area covered by Kodera forest. Give your answer in Kilometers square. (2mks)
   2.  
      1. Identify the methods used to represent relief of the area covered by the map.     (2mks)
      2. Identify two features found in grid square 6737.                                                (2mks)
   3.  
      1. Apart from forest, identify two other types of vegetations found in the area covered by the map. (3mks)
      2. State the general direction of flow of river Maugo.                                             (1mk)
   4. Citing evidence from the map give five economic activities carried out in the area   covered by the map.    (10 mks)
7.  
   1.  
      1. Define the term mineral .                                                                                 (2mks)
      2. Name three fossil fuels.                                                                                    (3mks)
      3. State threeforms in which minerals occur.                                                          (3mks)
   2.  
      1. State SEVEN factors which influence the exploitation of minerals.                         (7mks)
      2. Explain five significance of minerals to the economy of Kenya                               (10mks)
8.  
   1.  
      1. Define the term earthquakes.                                                                             (2mks)
      2. Name two types of earthquake waves.                                                                (2mks)
      3. Draw a simple diagram of the earth. On it indicate
         • Seismic focus                         (1mk)
         • Epicenter                                     (1mk)
   2.  
      1. Name four human activities which cause earthquakes.                                             (4mks)
      2. State three earthquake zones of the world.                                                                (3mks)
      3. State four effects of earthquake on crustal rocks.                                                     (4mks)
   3. Explain four negative effects of earthquakes.                                                                 (8mks)            
9.  
   1. Define the following terms.        
      1. Agro forestry.                                                                                                        (2mks)
      2. Afforestation                                                                                                        2mks)
      3. Re- afforestation                                                                                                  (2mks)
   2. Name three examples of each of the following.
      1. Hardwood tree species in Kenya forests                                                                (3mks)
      2. Exotic tree species planted in Kenya.                                                                   (3mks)
   3. State three factors that favour the growth and development of softwood forests in Canada. (3mks)
   4. Explain five measures being taken by the government of Kenya to conserve forest. (10mks)
10.  
    1.  
       1. Define the term mass wasting.                                                                                 (2mks)            
       2. Differentiate between weathering and mass wasting.                                             (2mks)
    2.  
       1. State four factors which influence mass wasting.                                                    (4mks)
       2. Apart from soil creep, state three other processes of slow mass wasting.              (3mks)
    3. You intend to carry out a field study on the processes of mass wasting within the local environment.   
       1. State three preparations you would carry out before the field study.                        (3mks)
       2. List three methods you would use to record the data.                                               (3mks)
       3. State five effects of soil creep to the human and physical environment.                 (5mks)
       4. Give three reasons why it is important to study mass wasting through field study. (3mks)

MARKING SCHEME 

1.  
   1.  
      1. Define the term atmosphere,
         • This is the mixture of gases, solid particles and liquid droplets suspended above the earth’s surface and held to it by gravitational force. 1 x 2 = 2
      2. Three components suspended in free atmosphere
         • Smoke particles
         • Salt particles
         • Dust particles
         • Water droplets 3 x 1 = 3
   2.  
      1. Main layers of the atmosphere zones of the atmosphere
         • Stratosphere
         • Mesosphere
         • Thermosphere 2 x 1 = 2
      2. Characteristics of the troposphere.
         • It is the lowest layer above the earth’s surface
         • It contains 75% of the total gases in the atmosphere.
         • It has 90% of the water vapour
         • Temperature decreases with increase in altitude
         • Pressure decreases upwards
         • Wind speed increases with increase of altitude. 3 x 1 = 3
2.  
   1.  
      1. Primary data are facts and figures collected directly from the field while secondary data is stored information.    1 x 2 = 2
      2. Methods of collecting statistical data apart from interview
         • Observation
         • Administering questionnaire
         • Taking measurements
         • Carrying out-experiments
         • Content analysis 3 x 1 = 3
3.  
   1. Simple Fold
      
   2.  Negative effects of folding
      • Fold mountains are a barrier to transport and communication
      • Folding may bury valuable minerals deep making mining expensive.
      • Folding cause a shadow effect on the leeward side. 2 x 1 – 3

4.  
   1. U – Upthrow 1
      V –Fault plane            1
      W – Down throw        1
   2. Compressional Force 
      Tensional Force
      Tear Force       2 x 1 = 2
5.  
   1. Types of weathering apart from biological
      • Mechanical/Physical weathering
      • Chemical weathering 2 x 1 = 2.
   2. Plants influence on weathering
      • Plants roots penetrate cracks in rocks widen the cracks in the process breaking them.
      • Rooks widen cracks to enter the rock them aiding chemical weathering.
      • Plants roots absorb minerals from rocks and make them decay easily.
      • Some plants growing on rocks keep the surface moist hence encouraging chemical weathering
      • Some plants during decay produce humic acids which react with rode minerals in the process encouraging chemical weathering.  3 x 1 = 3

Mapwork

6.  
   1.  
      1.  
         • Types scale used on the map
         • Representative fraction/Ratio
         • Linear           2 x 1 = 2
      2. One centimeter represents ½ kilometer  1 x 1 = 1
      3. 17km        1 x 2 = 2mks
      4.  
         • Number of full squares 0
         • Number of half squares = 15 ÷ 2 = 7.5
         • Area=  7.5 km²            1 x 2 = 2
   2.  
      1. Contour lines
         Trigonometrical station          2 x 1 = 2
      2. Features in grid square 6737
         • Dam
         • Footpath/track
         • Settlements 2 x 1 = 2mks
           
           
   3.  
      1. Apart from forest
         – Scrub vegetation
         - Scattered trees
         -Woodland vegetation 3 x 1 = 3mks
      2. General directions of River Mango is South East to North West 1 x 1 = 1mk
   4. Economic activities
      • There is transport evidence roads e.g Kisii – Kehancha
      • There is maize growing evidence flour mill grid square 9040.
      • There is brick-making evidence brick making factory in grid square 8843.
      • There is trade evidence market
      • There is livestock keeping evidence veterinary office grid square 7533.
        NB:   Economic activity must be tied to evidence.    5 x 2 = 10mks
7.  
   1.  
      1. Meaning of mineral
         - This is naturally occurring inorganic substance on or below the earth surface 1 x 2 = 2mks
      2. Fossil fuels
         • Coal
         • Petroleum
         • Natural gas 3 x 1 = 3mks
      3. Forms in which minerals occur
         • Weathering products
         • Alluvial deposits
         • Veins and lodes
         • Seams 3 x 1 = 3mks
   2.  
      1. Factors which influence exploitation of minerals.
         • Mode of occurrence of the mineral
         • Economic value of the mineral
         • Size of the mineral deposit
         • Quality of the Ore
         • Transport cost
         • Availability of labour
         • Methods of extraction
         • Government policy
         • Technological advancement
         • Availability of market for the mineral.          7 x 1 = 7mks
      2. Significance of minerals to economy of Kenya
         • Mining has created employment enabling Kenyans to earn.
         • Some minerals are exported earning the Country foreign exchange
         • Minerals have led to growth of some urban centres e.g. Magadi
         • Money earned from minerals is used infrastructure development.
         • Money that have been used in importing some raw materials is saved.
         • Minerals have uplifting living standards for those employed.          5 x 2 = 10mks
8.  
   1.  
      1. Meaning of earthquake.
         • This is a sudden earth movement which causes vibrations within the crust. 1 x 2 = 2
      2. Types of earthquake waves
         • Primary waves
         • Secondary waves
         • Longitudinal waves   2 x 1 2
      3.  
         
   2.  
      1. Human activities which cause earthquakes.
         • Explosives used in mining
         • Moving locomotives
         • Testing of nuclear bombs underground.
         • Construction of large water reservoirs          4 x 1 = 4mks
      2. Earthquake zones
         • The circum – pacific belt
         • The Mediterranean belt
         • The Rift valley
         • Boundaries of tectonic plates
         • Himalayas belt              3 x 1 = 3mks
      3. Effect of earthquakes on crustal rocks
         • Earthquakes cause crustal rocks to fracture/crack/break.
         • Earthquakes make crustal rocks to more horizontally, vertically or past each other
         • Earthquakes cause crustal rocks to band upwards or downwards.
         • Earthquakes cause the uplift on canaling crystal rocks        4 x 1 = 4
   3. Effects of earthquakes
      • Earthquakes may cause loss of lives.
      • Earthquakes may lead to damage/destruction of property
      • Earthquakes may lead to tsunamis leading to drowning of wasted land
      • Earthquakes can lead to disruption of transport and communication line.   4 x 2 = 8mks
9.  
   1.  
      1. Define
         Agro-forestry
         • This is the farming on trees in the same field with crops       1 x 2 = 2
      2. Afforestation
         • This is the planting of trees where forests did not exist         1 x 2 = 2
      3. Re-afforestation
         • This is the planting of trees to create forest where the vegetation existed but destroyed. 1 x 2 = 2
   2. Examples of
      1. Hardwood
         -Meru Oak
         -Teak
         -Mvule             3 x 1 = 3
      2. Exotic softwood
         • Cyprus
         • Pine
         • Eucalyptus             3 x 1 = 3
   3. Softwood in Canada.
      Factors favouring
      • Favourable climate
      • Sparse population
      • Availability of different tree spices
      • Availability of market for softwood      5 x 2 = 10mks
10. 1. 1. Mass wasting
          • The movements of weathered materials down a slope under the influence of gravity.1 x 2 = 2mk
       2. Mass wasting is the movement of weathered material down slope by gravity while weathering    is the breakdown of rocks in situ.           1 x 2 = 2mks
    2.  
       1. Factors which influence mass wasting.
          - Angle of slope
          - Human activities
          - Climate
          - Nature of material
          - Tectonic movements              4 x 1 = 4mks
       2. Processes of slow mass wasting other than soil creep
          -Rock creep    
          -Talus creep   
          -Solifluction
    3.  
       1. – Seek for permission
          - Carry re-visits
          -Do research on the topic            3 x 1 = 3mks
       2.  -photographing            -Tape recording
          - Sketching                  -Taking notes                          3 x 1 = 3mks
       3. Effects of soil creep
          -Walls bend
          -Tree trunks bend
          -Soil material collects at the base of slope
          -There is slope retreat
          -Displacement of soil part holes upper parts leaving it bare
          -Accumulation of soil on roads which interferes with transport.       5 x 1 = 5mks
       4. Importance of studying mass wasting through field study
          -Removes class monotony
          -Makes geography real
          -A learner is able to use skills learnt in class.       3 x 1 = 3mks)