Biology Paper 1 Questions and Answers - Arise and Shine Pre Mock Exams 2023

Instructions

• Answer all the questions
• All answers should be written in English 

FOR EXAMINER’S USE ONLY

QUESTIONS

1. Name the branch of biology that involves the study of:
   1. Organism for the sake of classifying them (1mark)
   2. Microscopic organisms (1 mark)
2. The diagram below represents a plant
   
   
   1. Name the division to which the plant belongs (1 mark)
   2. Give three reasons for your answer in (a) above (3 marks)
3. A student estimating a cell of an onion epidermal cell observed the following on the microscope field of view using a transparent ruler
   
   The student identifies 20 cells across the field of view Calculate the size of the cell in micrometres (3 marks)
4. State the functions of centrioles in a cell (2 marks)
5. Study the flow diagram below
   
   Name the substance U, V and W (3 marks)
   U ..............................................
   V  ..............................................
   W  ..............................................
6.                  
   1. State the deficiency diseases of each of the following vitamins (3 marks)
      1. B₁  ..............................................
      2. B₂  ..............................................
      3. B₆  ..............................................
   2. What is the role of roughage in a diet? (1 mark)
7. State two differences between osmosis and Active transport (2 marks)
8. In a certain experiment, the following observation was made:
   When red blood cell was placed in certain solution, the solution exerted more osmotic pressure leading to cell losing water molecules to become (crenated/shrunk)
   1. What type of solution was the cell placed in respect to the cell’s cytoplasms? (1 mark)
   2. By which physiological process did the cell lose water molecules? (1 mark)
   3. Name two substances that make a cell membrane (2 marks)
9. The diagram below represents a transverse section of a plant part Study it and answer the questions that follow
   
   
   1. Name the class in which the plant belongs (1 mark)
   2. Give a reason for answer (a) above (1 mark)
   3. State three adaptations for the structure labeled X to their functions (3 marks)
10. State THREE structural differences between arteries and veins in mammals (3 marks)
11.                        
    1. Why does carboxyhaemoglobin lead to death? (3 marks)
    2. Name two gaseous exchange sites in higlier plants (2 marks)
12. State the importance of the following features in gaseous exchange
    1. cartilage in the trachea 1 mark)
    2. Moisture on the surface of the alveoli (1 marks)
13. The equation below shows an oxidation reaction of flow food substances
    5C₅₁H₉₈O₆ + 145O₂→ 102CO₂ + 98H₂O + Energy
    1. Determine respiratory quotient of the Oxidation of the food substance above (3 marks)
    2. Identify the food substance (1 mark)
14.                          
    1. A dog weighing 152kg requires 216kg while a mouse weighing 50g Explain (2 marks)
    2. Under what condition is lactic acid formed in human muscles? (1 mark)
15. Equal amounts of crushed Irish potato were placed in equal volumes of hydrogen peroxide solution at indicated PH The volume of the gas produced was measured and recorded as shown in the table below (3 marks)
    

    PH	4.0	7.0	9.0
    Volume of gas (cm3)	2.7	7.0	9.0

    1. Name the gas that was produced (1 mark)
    2. Account for the difference in the volume of the gas produced in PH 40 and PH 90 (3 marks)
    3. Name two components of blood that are not present in the glomerular filtrate (2 marks)
16. Define the following terms (2 marks)
    1. Entomology
    2. Sensitivity
17. Give two examples of continuous variations in humans (2marks)
18.                      
    1. State the causative agent of the following diseases (2 marks)
       1. Typhoid
       2. Pneumonia
    2. State three preventive measures of schistosomiasis in human beings (3 marks)
19. Describe capture-recapture method of estimating population (3 marks)
20. State three advantages of asexual reproduction in organisms (3 marks)
21. The diagram below shows a phenomenon which occurs during cell division
    
    
    1. Identify the stage of cell division in which the phenomenon occurs (1 mark)
    2. State the importance of phenomenon taking place in the part labelled B (2 marks)
22. Name the region in plants where the following take place
    1. Primary growth (1 mark)
    2. Secondary growth (1 mark)
23. State three parameters that can be used to estimate growth in seedlings (3 marks)
24. State three reasons for classifying organism (3 marks)
25. The diagram below represents a transverse section of an ovary from certain flower
    
    
    1. Name the structure labeled W (1 mark)
    2. Name the type of placentation illustrated in this diagram (1 mark) 

MARKING SCHEME

1.                  
   1. Taxonomy
   2. Microbiology;
2.                    
   1. Pteridophyta;
   2. Presence of Sori;
      Presence of rhizomes;
      Presence of fronds;
3. Diameter of the field of view   =  4mm
   In micrometers = 4 x 1000 um   =  4000 um;
   No of cells =  20
                   Size of each cell = diameter of field of view
                                                         No of cells
          = 4000
               20;
         = 200um
4.                      
   • Formation of spindle fibres during cell division;
   • Formation of cilia and flagella;
5.              
   • U – water
   • V – Oxygen
   • W – Hydrogen (ions)
6.                    
   1.                
      1. Beriberi
      2. Pellegra
      3. Pernicious anaemia
   2. Increase/Ada bulk of the food enhancing peristalsis/Firm grip along lining of the Alimentary canal.

7. Osmosis	Diffusion
   Water moves along the concentration gradient Process utilize no energy	Molecules/particles move against concentration gradient Process utilize energy;

8.                        
   1. Hypertonic solution;
   2. Osmosis;
   3.                
      • Phospholipid;
      • Protein;
9.                      
   1. Dicotyledonae;
   2. centrally placed star – shaped xylem with phloem (alternating) between the arms of the xylem.
   3.                     is tied to (a)
      • Numerous/Elongated to increase the surface for absorption of water/mineral
        Salt/both;
      • Thin walled for faster absorption of water/ mineral salts/both;
      • Numerous mitochondria to provide energy for absorption of mineral salts
        Mark first 3

10. S.no	Arteries	Veins
    (i)	Walls are thick, muscular with more elastic fibres	Walls are thin’ less muscular with less elastic fibres;
    (ii)	Have no valves except at the base of large arteries	Have valves;
    (iii)	Have narrow lumen	Have wider lumen;

11.                    
    1. Stable/does not dissociate; reducing oxygen carrying capacity of Red blood cells;
       causing suffocation/ (OWTTE)
    2.                
       • Cuticle;
       • Lenticels;
       • Stomata;
       • Pneumatoprores/Breathing roots;
       • Aerenchyma tissue;
         (Mark 1st  2)
12.                          
    1. Keep the trachea open;
    2. Dissolve respiratory gases for faster diffusion;
13.                    
    1. RQ = Volume of CO₂ Produced
                Volume of oxygen consumed
       = 102;
          145
       = 0.7;
    2. Fats
14.                  
    1.  A mouse has large surface area to volume ratio; loses more energy/heat; hence the need to compensate for the loss;
       Max marks = 2
    2. Insufficient oxygen/Anaerobic condition;
15.                
    1. Oxygen;
    2. More gas/oxygen produced at PH 9.0 than PH 4.0, PH 9.0 is optimum/suitable; for the activity of enzyme catalase
    3.                    
       • Blood cells/Acc Red blood cells/white blood cells/platelets;
       • Plasma proteins;
16.                
    1. (Branch of biology that deals with the) study of insects
    2. Ability of an organism to detect and respond to changes in the environment;
17.              
    • Skin Colour/Pigmentation
    • Body weight
    • Span of the hand
    • Height
18.                          
    1.                
       1. Salmonellatyphi
       2. StreptococcusPneumoniae
    2.                      
       • Proper disposal of feaces/urine in latrines;
       • Drinking water should be boiled/treated;
       • People should wear protective shoes/water proof shoes/gumboots when waling in water in infested with snails with molluscicides
         First 3 correct 3 x 1 = 3mks
19.                  
    • Capture the organisms using appropriate means;
    • Mark with water proof paints;
    • count the number and release;
    • capture again after 48 hours and use the formular to estimate the population;
20.                
    • Beneficial characteristics are retained
    • Organisms mature faster;
    • does not depend on population/fertilization/Fruit and seed dispersal;
    • New plants obtain nourishment from their parent/hence can survive temporarily   during unsuitable environmental condition;
21.                  
    1.  Prophase 1; (Rej wrong spelling/prophase alone)
    2. Recombination of genes; leading to variation;
22.                        
    1. Apical meristems/Root shoot tips
    2. Cambium
23.                    
    • Surface area of leaves
    • Height/Length;
    • Dry weight/mass;
24.                
    • Bring organism with similar characteristics together and separate them from these with different features
    • Place the organisms into their correct group for reference;
    • Arrange information about living organisms in an orderly manner;
    • Help understand evolutionary relationships between different organisms;
25.                  
    1. Ovules;
    2. Axile;