BIOLOGY PAPER 3 - KAPSABET BOYS 2019 TRIAL MOCK EXAMINATION

1. Study the organisms below
   
   
   1. Complete and use the key below to identify the organisms (2mks)
      1a) Organism with endoskeleton …………………………………………………………...go to 2
      1b) __________...........................................................................go to 4
      2a) Has scales on the body ………………………………………………………………..…..go to 4
      2b) Has no scales on the body …………………………………………………………….…mammalian
      3a) Has cephalothorax …………………………………………………………………………...Arachnida
      3b) Has no cephalothorax …………………………………………………………….………..go to 5
      4a) ___________________________.............................................Pisces
      4b) Has no fins …………………………………………………………………………………………go to 7
      5a) Has three pairs of legs ………………………………………………………………………..Insect
      5b) Has more than three pairs of legs ……………………………………………………….go to 6
      6a) Two pairs of legs per segment …………………………………………………………..Diplopoda
      6b) One pair of legs per segment …………………………………………………………….Chilopoda
      7a) Has feathers ………………………………………………………………………………………… Aves
      7b) Has no feathers …………………………………………………………………………………go to 8
      8a) Has a tail ……………………………………………………………………………………………Reptilia
      8b) Has no tail …………………………………………………………………………………………Amphibia
   2. Identify the organisms above using the completed key above (6mks)
      Specimen                        Steps followed                                 Identity
      A                                    ___________________           ______________________
      B                                    ___________________           ______________________
      C                                     __________________            ______________________
      D                                    __________________             ______________________
      E                                     __________________             _____________________
      F                                     _________________               ______________________
   3. Name the phylum in which specimens C, E and F belong to. (1mk)
   4. Give three reasons for your answer in (c) above (3mks)
   5. Name one feature that is common in organisms B, E and D (1mk)
2. You are provided with the following;
   • Hydrogen peroxide
   • Specimen K
   • Pestle and mortar
   • 4 test tubes
   • A scalpel
   • Source of heat
   • Test tube holder
     Using a scalpel, obtain three peeled cubed from specimen K measuring about 1cm x 1cm x 1cm. For the first cube, you are required to boil it in water for five minutes. For the second cube, you are required to crush it into a paste. For the last cube, you are required to use it as it is.
     Label three test tubes A, B and C and put 2ml of hydrogen peroxide in each test tube. To test tube A, add the boiled cube and record your observation.
     To test tube B. add the crushed paste and record your observation.
     To test tube C, add the unboiled cube remaining and record your observation.
     1. Complete the table below (3mks)
        

        Test tube	Observation
        A
        B
        C

     2.  Explain your observation in test tube A (1mk)
     3. Between test tubes B and C, in which test tube was the volume of foam produced the highest? Explain (3mks)
     4. Apart from temperature, state two other factors that affect the rate of enzyme controlled reactions (2mks)
3. The photographs below shows specimen of different types of fruits. Examine them and answer the questions that follow.
   
   
   1. State four differences between specimen P and R (4mks)
   2. State the types of gynoecium and placentation of specimen P, S and V (4mks)
      1. Specimen P Gynoecium 
                           Placentation 
      2. Specimen S Gynoecium 
                           Placentation
      3. Specimen V Gynoecium 
                           Placentation 
   3. In the table below name the mode of dispersal for each specimen and the features that adapt the specimen to its mode of dispersal. (6mks)
      

      Specimen	Mode of dispersal	Adaptive features
      P
      Q
      R
      S
      T
      v

   4. Draw and label a plan diagram of specimen V (4mks)

MARKING SCHEME

1.  
   1. 1b- Organism with exoskeleton
      4a – Has fins

   2. Specimen	Steps followed	Identity
      A B C D E F	1a, 3a 1a, 2a, 4a 1b, 3b, 5b, 6b 1a, 2a, 4b, 7b, 8a 1a, 2a, 4b, 7a 1b, 3b, 5a	Arachnida Pisces Chilopoda Reptilia Aves Insecta

   3. Arthropoda  reject  Antropoda or arthropoda.
   4. – They all have an exoskeleton
      - They all have segmented bodies
      - They all have jointed appendages/limb
   5. Scales;

2.  

   1. Test tube	Observation
      A	No effervescence/no bubble production /No foam production
      B	High effervescence rate/high rate of bubble formation
      C	Little effervescence/ bubble formation/little foam formation.

      
      Reject no reaction
   2. No effervescence /bubble formation/form formation because boiling denatured the enzymes (catalase enzyme) hence hydrogen peroxides, was not broken down into water, and oxygen gas.
   3. Test tube B, because crushing of the cube increased the surface area for proper enzyme (catalase) action hence a high volume of hydrogen peroxide was broken down into water and oxygen compared to the cube in test tube c  which has a small surface area expose to the hydrogen peroxide solution.
   4. PH, enzymes and substrate concentration contraction, enzyme inhibitors, co-enzymes and co-factors.
3.  
   1. -  P has one seed while R has many seeds
      - P has a thick pericarp while R has thin
      - P has distinct epicarp, mesocarp and endo carp while R have the three layer’s indistinct suture lines.
      - P has a hollow seed while the seeds of are not hollow.
   2. -    Specimen P – Gynoecium is monocarpous placentation basal.
      - Specimen S – Gynoecium is syncarpous spacentation parietal
      - Specimen V – Gynoecium is syncarpous placentation is axile/central

   3. Specimen	Mode of dispersal	Adaptive features
      P	Water	Hairy mesocarp /air spaces for buoyancy
      Q	Wind	Wing-like membranous structure/extensions
      R	Self by explosive mechanism	Has lines of weakness/sutures
      S	Animals	Fleshy /succulent
      T	Wind	Has hair-like projections/parachute of hairs
      V	Animals	Fleshy /succulent

   4. A plan diagram of specimen V