Biology Paper 1 Questions and Answers - Bondo Mocks 2021 Exams

• Answer all questions
• Candidates should answer the questions in English.

1. The diagram below represents part of an animal cell. Study it and answer the questions that follow.

         
   1. Identify the organelle marked A.           (1 mark)
   2. Give three functions of the organelle named in (a) above (3 marks)
2. Name the organism that causes each of the following diseases:      (2 marks)
   1. Amoebic dysentery
   2. Bilharzia.
3. The diagram below represents an organelle.
           
   1. State the function of the organelle (1 mark)
   2. Label on the diagram, the parts of the organelle where:
      1. Oxygen gas is produced as a by product (1 mark)
      2. Carbon (IV) oxide fixation takes place (1 mark)
4. State two functions of bile salts           (2 marks)
5. Name two classes of phylum Arthropoda whose members have a cephalothorax.      (2 marks)
6. The diagram below shows part of a leguminous plant.
          
   1. Name the structure labelled L. (1 mark)
   2. Identify the micro-organism that would be contained in structure L. (1 mark)
   3. What is the significance of the micro- organism named in b) above?(1 mark)
7. The following is a portion of a nucleic acid molecule.
   G-A-C-U-A-G-A-C-G
   1. Name the type of nucleic acid shown above.             (1 mark)
   2. Give a reason for your answer in b) above.                     (1 mark)
   3. Write the base sequence of the strand that is complementary to the portion shown above    (1 mark)
8. Name the chemical substance in plants that promotes:           (3 marks)
   1. Ripening of fruits
   2. Flowering in plants.
   3. Leaf fall in plants.
9. Study the diagram below and answer the questions that follow.
         
   1. What process is represented by the arrows? (1 mark)
   2. Identify the type of cell labelled 4.                   (1 mark)
   3. Name the tissue formed by each of the following cells. (2 marks)
      1. 1 …………………….……………………………………………………….
      2. 3 ……………………….…………………………………………………….
10. The equation below represents oxidation of a certain food substance.
    C₁₈H₃₆O₂ + 26O₂ → 18CO₂ + 18H₂O
    1. Calculate the respiratory quotient of the substance being oxidized. (2 marks)
    2. Name the likely food substance being oxidized (1 mark)
    3. State one reason why respiratory quotient values are important to work out (1 mark)
11. Study the diagram below and answer the questions that follow.
          
    1. Name the parts labelled
       1. Y.................................................................................................    (1 mark
       2. Z.................................................................................................          (1 mark)
    2. Apart from being moist, explain two other adaptations of the part labeled X.     (2 marks)
12. A strip of herbaceous Tradescantia was cut longitudinally as shown and placed in solution X. After one hour the strip appeared as shown below. 
            
    1. What physiological process was being investigated? (1 mark)
    2. What was the nature of solution X?                      (1 mark)
    3. Account for the results at the end of experiment after one hour.       (3 marks)
13. On a hot sunny day, an adult elephant flaps its ears twice as much as it’s young one. Explain this observation.                                                                      (3 marks)
14. The diagram below shows stages in the process of feeding by amoeba.
         
    1. Name the part labelled A.                                                                    (1 mark)
    2. Name the process illustrated in the diagram above.                            (1 mark)
    3. Identify the type of cell in the human body that exhibits this process.      (1 mark)
15. A horse has 64 chromosomes in its somatic cells while a donkey has 62. A mule is produced when a horse mates with a donkey. However, the mule is sterile.
    1. Why is the mule sterile?                                                                       (1 mark)
    2. Work out the number of chromosomes in each somatic cell of a mule. (2 marks)
16.  
    1. Differentiate between Homologous structures and Analogous structures as used in evolution. (2 marks)
    2. Explain comparative embryology as an evidence of organic evolution        (3 marks)
17. The diagram below represents a type of neuron.
           
    1.  Identify the neuron                                                                               (1 mark)
    2. Give a reason for your answer in a) above.                                         (1 mark)
    3. Using an arrow, indicate on the diagram the direction of an impulse through the neuron.      (1 mark)
18. The diagram below represents part of the mammalian blood circulatory system and some associated glands.
           
    1. Name the blood vessels labelled A and B. (2 marks)
    2. Which of the blood vessels will have the highest sugar concentration under the following conditions:
       1. After a heavy meal (1 mark)
       2. During fasting       (1 mark)
19. Name one co-factor and one co-enzyme required for blood clotting process to take place normally
    1. Co-factor…………………………………….……………………… (1 mark)
    2. Co-enzyme …………………………………….…………………… (1 mark)
20. The diagram below represents a structure in a mammalian kidney. Study it and answer the questions that follow.
    
    1. Identify the structure.                                                                           (1 mark)
    2. State the role of the part labelled C.                       (1 mark)
    3. Which hormone is involved in the function of the part labelled D?    (1 mark)
    4. Give three ways in which the part labelled B is adapted for it`s function.            (3 marks)
21.  
    1. Define pollination.         (1 mark)
    2. Give two factors that hinder self-pollination and self-fertilization in plants  (2 marks)
22. State the role of insulin hormone in homeostasis                                          (1 mark)
23. The diagram below shows some growth in a plant.
    
    1. Name the type of growth shown in the diagram. (1 mark)
    2. Name the part labeled A             (1 mark)
    3. What is the function of the part labeled B?                              (1 mark)
24. Below are two different views of a mammalian bone. Study it and answer the questions that follow.
    
    1. Identify the bone (1 mark)
    2. Give a reason for your answer in (a) above (1 mark)
25. Explain how plants compensate for their inability to carry out locomotion.              (3 marks)

MARKING SCHEME

1.  
   1. Golgi apparatus/Golgi body
   2.  
      1. Packaging of glycol-proteins;
      2. Formation of Lysosomes
      3. Secretion of synthesized proteins/Secretion of enzymes;
2.  
   1. Entamoeba histolytica;
   2. Schistosoma japonicum;    Acc. Schistosoma spp
3.  
   1. Site for photosynthesis;
   2.  
      1. Grana/granum;
      2. Stroma;
4.  
   1. Emulsification;
   2. Provide an alkaline medium for the functioning of pancreatic enzyme;
   3. Neutralize the acidic chyme from the stomach;
      MARK 1ST TWO.
5.  
   1. Arachnida;
   2. Crustacea;
6.  
   1. Root nodule; Rej Nodule alone.
   2. Rhizobium bacteria/ Nitrogen fixing bacteria;
   3. Fixing nitrogen// converts nitrogen into nitrates for the plant;
7.  
   1. Ribonucleic acid; Rej RNA
   2. Presence of Uracil;
   3. C-T-G-A-T-C-T-G-C;
8.  
   1. Ethene/Ethylene;
   2. Florigen;
   3. Abscissic acid;
9.  
   1. Cell differentiation;
   2. White Blood Cell;
   3.  
      1. 1- Epithelium;
      2. 3 - Smooth muscle;
10.  
    1. CO₂ produced  =  18 ;  = 0.69 = 0.7;
       O₂ consumed        26
    2. lipids; Acc. Fats & oils
    3.  
       1. Provides information on the type of substrate oxidised;
       2. Gives information on the type of respiration/metabolism taking place;
11.  
    1.  
       1. Y – Gill raker;  Rej rakers
       2. Z – Gill bar;
    2.  
       1. Thin walled for faster diffusion of respiratory gases;
       2. Highly vascularised/dense network of blood capillaries to transport the respiratory gases;
12.  
    1. Osmosis;
    2. Hypotonic;
    3. The parenchyma cells on the cut surface absorbed water by osmosis; they became turgid/expanded; the epidermal cells have cuticle and did not absorb water causing the outward bending;
13. The adult elephant has a smaller surface area to volume ratio; it loses heat slowly to the environment; hence flaps it’s ears many times (to create air currents around the body) to cool the body; ACC. THE CONVERSE.
14.  
    1. Pseudopodium;
    2. Phagocytosis;
    3. White blood cells;
15.  
    1. Horse and donkey do not belong to the same species;
    2. ⁶⁴/₂ +⁶²/₂ = 32+31; = 63;
16.  
    1. Homologous structures have a common embryonic origin but are modified to perform different functions in different species; Analogous structures have different embryonic origins but modified to perform the same function;
    2. It involves the study and comparison of different embryos; Vertebrate embryos in their early stages of development, show resemblance/similarities (eg all possess a tail); this suggests that they had a common ancestral origin;
17.  
    1. Motor neurone;
    2. Cell body is at one end of the axon;           i     
    3. NB: From cell body towards the terminal dendrites.
18.  
    1.  
       • A-  Hepatic portal Vein;
       • B-   Hepatic Vein;
    2.  
       1. A;    Acc. Hepatic portal vein.
       2. B;     Acc. Hepatic vein
19.  
    1. Calcium ion;         Rej  Ca2+
    2. Vitamin K;
20.  
    1. Nephron;
    2. Reabsorption of water;
    3. Aldosterone;
    4.  
       1. Long and coiled to provide a large SA for reabsorption;
       2. Coiling reduces the speed of flow of the filtrate and allow more time for reabsorption;
       3. Cells lining the tubule have numerous mitochondria to provide energy for (active) reabsorption;
       4. The cells have micro-villi to increase the SA for reabsorption;
       5. Is supplied with numerous blood capillaries for transportation of reabsorbed substances;
          MARK 1ST THREE.
21.  
    1. The transfer of pollen grains from an anther to the stigma;
    2.  
       1. Dioecism;
       2. Protandry
       3. Protogyny;
       4. ) Heterostyly; Acc. Anthers located below the stigma
       5. Self sterility;
          MARK 1ST TWO.
22.  
    1. It stimulates the liver cells to convert excess glucose into glycogen/fats for storage;
    2. It inhibits conversion of glycogen into glucose in the liver;
    3. Increases oxidation of glucose to yield energy;
23.  
    1. Secondary growth;
    2. A- Primary phloem;
    3. Cells divide by mitosis to form secondary phloem and secondary Xylem/ For secondary;
24.  
    1. Thoracic vertebra;
    2.  
       1. Long neural spine for attachment of muscles;
       2. Short transverse processes that bear tubercular facets for articulation with tuberculum of the rib;
       3. Presence of capitular demifacets on the centrum that articulates with capitulum of the rib;
          MARK ANY ONE. 
25.  
    1. Manufacture their own food by Photosynthesis;
    2. Pollination is carried out by wind or insects;
    3. Disperse their fruits/seeds through wind, animals or self-explosive mechanism;
    4. Absorb/obtain water and mineral salts from the soil by their roots;
       MARK ANY THREE.