Biology Paper 1 Questions and Answers - Kapsabet Pre Mock Exams 2021/2022

BIOLOGY
PAPER 1: THEORY

INSTRUCTIONS TO CANDIDATES

• Write your name, school and index number in the space provided above.
• Sign and write the date of the examination in the space provided.
• Answer all the questions in the spaces provided.

1.        
   1. Name the external feature which is common in birds, fish and reptiles (1mk)
   2. State two characteristics of fungi (2mks)
2. State the functions of the following parts of a light microscope (2mks)
   1. Objective lens
   2. Diaphragm
3.          
   1. Define the term seed dormancy
   2. The diagram below represents a stage during germination of a seed
      
      1. Name the part labelled x
      2. State one function of the part named above
4.        
   1. State two causes of chromosomal mutations (2mks)
   2. Distinguish between continuous variation and discontinuous variations (2mks)
5. The diagram below shows a section through a plant organ
   
   
   1.          
      1. Name the class of the plant which the section was obtained (1mk)
      2. Give a reason for your answer in (a) (i) above (1mk)
   2. State the functions of the part labeled F (1mk)
6. State the function of the following cell organelles \
   1. Ribosome (1mk)
   2. Lysosomes (1mk)
7.              
   1. Pregnancies continues if the ovary of an expectant mother is removed after 4 months explain (2mks)
   2. What is the role of the testes in the mammalian reproductive systems (2mks)
8. In an experiment the shoot tip of a young tomato plant was decapitated as shown in the diagram below
   
   
   1. State the expected results after 2 weeks (1mk)
   2. Give a reason for your answer in (a) above (2mks)
9.        
   1. Distinguish between diffusion and active transport (2mks)
   2. State one role that is played by osmosis in (2mks)
      1. Plants
      2. Animals 
10.               
    1. Name the gaseous exchange surface in insects (1mk)
    2. How is the surface named in (a) above suited to its function (2mks)
11. Explain why plants do not require specialized excretory organs (2mks)
12. Explain how the following factors affect the rate of photosynthesis
    1. Concentration of carbon (iv) oxide (1mk)
    2. Light intensity (1mk)
13. Explain what happens in human when concentration of glucose in the blood decreases below the normal level (4mks)
14. Explain how the carnassial teeth of a dog are adapted to their function (2mks)
15.            
    1. State three structural differences between arteries and veins in mammals (2mks)
    2. Name a disease that causes thickening and hardening of arteries (1mk)
16. from the equation given below, calculate the respiratory quotient (RQ)
    2C₅₁H₉₈O₆ + 145O₂  → 102CO₂ + 98H₂O + Energy
    1. Show your working (2mks)
    2. Identify the substrate respired in the above equation (1mk)
17.        
    1. What is fertilization (1mk)
    2. Explain how double fertilization takes place in plants (2mks)
18. In an experiment, the pituitary gland of a rat was removed
    1. state the effect this will have on the quantity of urine produced by the rat (1mk)
19. The diagram below show part of a food relationship in an ecosystem
    
    
    1. Name the food relationship shown in the diagram (1mk)
    2. Name the trophic level occupied by organism A (1mk)
    3. What is the main source of energy in the ecosystem shown in the diagram above (1mk)
20. Other than transport. State two other function of mammalian blood (2mks)
21. Below is a nucleic acid stand
    
    
    1. name the nucleic acid (1mk)
    2. give a reason for your answer in (a) above (1mk)
22. Name two structures of gaseous exchange in aquatic plants (2mks)
23. What is the significance of chiasma formation during meiotic cell division (1mk)\
24.                    
    1. Define the term evolution (1mk)
    2. Give two evidence of organic evolution (2mks)
25. Identify the stage of cell division below (1mk)
    
26. State two characteristics of cells found at the apical meristems (2mks)
27. The diagram below represents a mature fruit of a certain plant
    
    
    1. State the agent dispersal for the fruit ……………………………………………………… .(1mk)
    2. Give a reason for your answer in (a) above ………………………………………………… (1mk)
    3. State two other characteristics of fruit and seed dispersal by the agent named in (a) above (2mks)
28. Explain how the following adaptations will reduce the rate of transpiration (2mks)
    1. Sunken stomata
    2. Leaf folding
29. Name the disease caused by each of the following microorganism (2mks)
    1. Plasmodium falciparum 
    2. Entamoeba histolytica
30. State two properties of monosaccharaides (2mks)

MARKING SCHEME

1.        
   1. Scales/scale
   2.      
      • Most have cell wall made up of cultic (or cellulose) rej cellulose alone
      • Most reproduce by means of spores/sporulation
      • They are eukaryote/eukaryotic
      • They are heterotrophy/ lack chloroplasts/some are saprophytic while others are parasitic
      • have network of myphae/mycelia
      • store food in form of glycogen or oil droplets (both must be mentioned)
      • obtains food/nutrients\
      • Shelter
2.          
   1. Magnification of the object /image
   2. Regulate amount of light (falling on the object on microscope) acc; adjust/control amount of light
3.     
   1. a period of very minimal metabolic activity in an organism
   2.      
      1. epigeal
      2. protection of the delicate plumule; pulls the cotyledons above the ground. Rej shoot
4.        
   1. rej; cosmic rays as mutageous on chromosomes
      Radiations such as alpha, gamma, beta UV and X-rays least one
      rej; symbol a β and increases in temperature
      • chemicals such as colchicine, phenols, bromate, pesticides at least one
      • heavy metals eg lead mercury rej symbols
      • viruses such as papilloma rej; mustard gas-effects gene mutation
   2. Continuous variation is a variation that has no limit on the value that can occur within a population. Discontinuous variation is a variation that has distinct groups for organisms to belong to.
5.     
   1.          
      1. Dicotyledonous rej dicotyledonous
      2. Vascular bundles arranged in a ring/ presence of vascular
         rej pith-not visible also found in the root of monocots
         rej intra vascular bundle
   2. (divides to) give rise to secondary thickening (growth/ increase in growth/ diameter/ width of stem/ gives rise to new/additional xylem and phloem tissues
6.         
   1. site for protein synthesis
      rej autolysis
      NB must mention effects of lytic enzymes
   2. break down worn out cell/organelles/ food materials
7.       
   1. the placenta/takes the role of the ovum of producing the hormone progesterone (which maintains pregnancy)
   2. Production of gametes/spermatozoa acc male gamete/male sex cells
      Production progesterone hormone which maintains pregnancy acc male sex hormones
8.         
   1. auxiliary/lateral buds spront/branches will be formed
   2. decapitation removes the hormone/ouxins/IAA which is produced in the terminal bud/the stem tip; abseul/ remove of the hormone/auxins/IAA promote branch/development of auxiliary lateral buds.
9.        
   1. In diffusion rej movement molecules) move from a highly conc. Region to a slowly conc. Region while in active transport molecules move from a lowly concentration region to a highly conc. Region on diffusion molecules move along conc. Gradient while in active transport molecules move against conc. Gradient. No energy is required in diffusion while energy is required in active transport/active requires carrier molecules while carrier molecule not required in diffusion
   2.          
      1. absorption of water from the soil by root hair cells/movement of water between plant cells/from cell to cell/opening one closing of stomata/support in herbaceous plant due to turgidity/feeding in insectivorous plant.
      2. Water reabsorption by blood capillaries from renal tubules/absorption of water in colour dicututary/canal/gut movement of water from cell to cell in animals
10.                 
    1. tracheole rej trachea/ tracheole system
    2. moist for gases to dissolve (in solution) branched/ramify numerous tubes to increase surface area (for gaseous exchange)
11. Some wastes eg gases easily diffuse out . waste products are mainly made from carbohydrate and (NB; must mention some/most) hence are not harmful as proteineous materials/waste products are formed slowly/little accumulation of wasted/plants are leas active/some waste products (such as O₂) and are usable-recycled some waste products are stored in non-toxic forms in leaves, flowers, fruits and old bark.
    1. Rate of photosynthesis increases as CO₂ concentration increases up to a certain level/optimum level and (vise versa)
       NB; must mention up to optimum level or certain level
       Acc Reverse: the rate of photosynthesis decreases with decreases in CO₂ concentration until it stop rate of photosynthesis increases as the light intensity up to an optimum level and vice versa
12.          
    1.  rate of photosynthesis increases as CO₂ concentration increases up to a certain level/optimum level and (vice versa)
       NB; must mention up to optimum level or certain level
    2. Acc; reverse: the rate of photosynthesis decreases with decrease in CO₂ concentration until it stop rate of photosynthesis increases as the light intensity up to an optimum level and vice versa
13. Pancreases releases glucagons to stimulate liver cells to convert stored glycogen to glucose; fat converted to glucose/reduces rate of respiration. Rej if source of glycogen is the liver.
14. large/powerful for cracking/breaking/crushing bone/slide past each other/ scissor- like for shearing/cutting/slicing (off) flesh/tendons/skin from bone
15.          
    1.    
       

       Arteries	Veins
       Thick muscular wall	This muscular walls
       No valves (expect at bases of pulmonary artery and aorta)	Have valves
       Narrow lumen	Wide lumen

    2. atherosclerosis
16.               
    1. CO₂ produced=     102    
           O₂ used            145
       =0.703
    2. fats
17.         
    1. Fertilization- fusion of male and female nuclei gametes; to form a zygote rej fusion of gametes
    2. One male nuclei fuses with egg to form a (diploid) zygote; while the other male nuclei fuses with (two) polar cells to form (triploid) endosperm nucleus;
18.           
    1. More urine will be produced/diuresis
    2. Lack of Anti-diuretic hormone/vasopressin therefore less water is reabsorbed
19.          
    1. food web
    2. Primary produce
    3. the sun/sunlight
20. regulation of PH of the body
    Distribution of heat around the body/regulates temperature
21.            
    1. RNA
    2. Has bas uracil
22. stomata
    aerenchyma
23. important genetic exchange takes place resulting in variation
24.        
    1. gradual change of living organism from simple life forms to more complex life forms
    2. Palaentology and fossils
       Taxonomy
25. anaphase II
26. thin wall, dense cytoplasm, large vacuole
27.            
    1. wind
    2. hairy surface
    3. light seeds
       small size seeds
       winged-seeds
28.             
    1. protects stomata from external forces such as winds and air currents reducing rate of transpiration
    2. covers the leaf, thus covering stomata, preventing exposure of tyhe stomata to external forces eg direct sunlight, winds hence reducing rate of transpiration.
29.              
    1. malaria
    2. amoebic dysentery
30. Cannot be broken down further into simpler sugars.
    Crystalline, colourless
    Soluble in water.