BIOLOGY PAPER 1 - 2020 KCSE PREDICTION SET 1 (QUESTIONS AND ANSWERS)

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INSTRUCTIONS TO CANDIDATES:

  • Answer all the questions in this question paper
  1. Name the cell organelles that would be abundant in:
    1. White blood cells destroying pathogens                      (1mk)
    2. Palisade mesophyl cells                                             (1mk)
    3. Skeletal muscle cells                                                 (1mk)
  2. The following graph represents a growth pattern observed in a group of animals
    BIOP1Q2ALL
    1. Name the type of growth shown above (1mk)
    2. Name the phylum of animals whose members display the growth pattern named in (a) above (1mk)
    3. Identify the process which leads to increase in body size at the part marked S (1mk)
  3.  
    1. When observing a specimen through a light microscope, a student noted that the field of view was dark. Name 2 parts of the microscope that the student should adjust to make the field of view clear (2mks)
    2. A specimen was magnified 1000 times by a light microscope whose eye piece lens magnification is x10. Calculate magnification of objective lens (2mks)
  4. The flow diagram below represents a process of photosynthesis. Study diagram and answer the questions that follow
    BIOP1Q4ALL
    1. Name the substances labeled (3mks)
    2. Write an equation to show the process illustrated above     (1mk)
  1. Name the parts of the body of a mammal where each of the following types of joints are found (3mks)
    1. Fixed joints
    2. Gliding joint
    3. Huge joint
  1. The following is a diagrammatic representation of protein synthesis. Study and answer the questions that follow.
    BIO66GREAT
    1. Name process R     (1mk)
    2. Where in the cell does R take place?  (1mk)
    3. Name
      1. Product Q         (1mk)
      2. Part X            (1mk)
  1.  
    1. Name an element which is a present in proteins but is not in carbohydrates (1mk)
    2. State three functions of proteins in the human body       (3mks)
  1. State the functions of the following cell structures during cell division (2mks)
    1. Centriole
    2. Centromere
  1. In a blood test, a few drops of anti- serum were added to two samples of blood. It was observed that agglutination occurred. What were the possible blood groups of the two blood samples   (2mks)
  2. Name the division of the kingdom Plantae with the following spores producing bodies (2mks)
    1. Sori
    2. Sporangium
  3.  
    1. What structure in a mammal is represented by the following?                                 (3mks)
      1. The rubber balloon
      2. The syringe case
      3. The plunger
    2. Describe what happens if the rubber plug is pulled in the direction shown by the arrow (1mk)
      BIOP1Q11ALL
  4.  
    1. Define the term alleles                                                                                                (1mk)
    2. Explain why the body temperatures of a healthy human beings must rise up to 390C on a humid day  (2mks)
    3. In an experiment, a piece of brain was removed from a rat. It was found that the rat had large fluctuation of body temperatures. Suggest the part of the brain that had been removed (1mk)
  1. Name the causative agent of the following diseases in humans (2mks)
    1. Ameobic dysentry
    2. Candidiasis
  2.  
    1. Define the term immunity       (1mk)
    2. Distinguish between natural immunity and acquired immunity   (2mks)
    3. Identify one immunizable disease in Kenya       (1mk)
  1. The chart below shows a feeding relationship in a certain ecosystem
    BIOP1Q15ALL
    1. Construct two food chains ending with a tertiary consumer in each case (2mks)
    2. Suggest two ways in which the ecosystem would be affected if there was a prolonged drought(2mks)
  1. State two functions of muscles found in the alimentary canal of mammals (2mks)
  2. Study the reaction below and answer the questions that follow
    BIO17GREAT
    1. What biological processes are represented by A and B (2mks)
    2. Identify the product Y           (1mk)
    3. State the bond represented by X         (1mk)
  1. State one use of each of the following plant excretory products
    1. Tannins    (1mk)
    2. Colchines (1mk)
    3. Quinine       (1mk)
  1. State two characteristics of aerenchyma tissue       (2mks)
  2. The table below shows the percentage composition by volume of inhaled and exhaled air

    Gas

    Inhaled air %

    Exhaled air %

    Oxygen

    21

    16

    Carbon(IV) oxide

    0.04

    4.0

    Nitrogen

    79

    79


    1. By what percentage is carbon (IV) oxide concentration in inhaled air higher than exhaled air (2mks)
    2. Explain the differences in the composition of the gases between inhaled and exhaled air (3mks)
  3.  
    1. what is metamorphosis       (1mk)
    2. What is the biological importance of the larval stage during metamorphosis            (2mks)
  1. Explain how the following forces contributes to the movement of water up the xylem vessels (2mks)
    1. Cohesion
    2. Adhesion
  1. A solution of sugarcane was boiled with hydrochloric acid; sodium hydrogen carbonate was added to the solution which was then heated with benedict’s solution. An orange precipitate was formed
    1. Why was the solution boiled with hydrochloric acid?        (1mk)
    2. To which class of carbohydrates does sugarcane belong?  (1mk)
    3. State the form in which carbohydrates are stored in      (2mks)
      1. Plants
      2. Animals
  1. How are lenticels adapted for gaseous exchange? (2mks)
  2. State the importance of the following process that takes place in the nephrons of human kidney
    1. Ultrafiltration             (1mk)
    2. Selective reabsorption          (1mk)
  1. The diagram below represents a section or portion of a certain nucleic acid With a reason, identify the types of nucleic acid whose portion is shown above
    BIOP1Q26ALL
    Identity           1mk
    Reason          1mk


MARKING SCHEME

  1.  
    1. lysosomes
    2. chloroplast
    3. mitochondria( answer must be in plural)
  1.  
    1. intermittent growth curve
    2. Arthropoda( correct spelling)
    3. moulting
  1.  
    1. mirror
      Diaphragm
    2. total magnification =eyes piece lens magnification × objective lens magnification
      1000 = 10 × y
      1000/10= y
      y= ×100
  1.  
    1. A- Hydrogen ions
      B- carbon iv oxide
      C- carbohydrates ( accept glucose)
                            chlorophylL
    2. 6CO2 + 6H2O       →       C6H12O6 + 6O2
                             sunlight

      (accept word equation)
  2.  
    1. skull; pelvic bone
    2. ankle; wrist
    3. knee ; elbow
  1.  
    1. condensation
    2. ribosome
    3. Q- Polypeptide
      X- peptide bond
  1.  
    1. nitrogen
    2. form the structure of animal fossils/ keratin in hair/ collagen in tendons and ligaments/ form myosis in muscles/ form enzymes and hormones/ form casein in milk/ source of enerhy during starvation
      1. centriole- produce spindle fibres
      2. centromere- holds chromatids together/ provide point of attachment to spindle fibres
  1. AB and B
  2.  
    1. sori- Pteridophyta
    2.  sporangium- Bryophyta (for all spelling must be correct)
  1.  
    1.  
      1. the rubbber balloon- lungs
      2. syringe case – thoracic vertebrae
      3. the plunger – diaphragm
    2. the balloon become inflated
  2.  
    1. Alleles- contrasting pair of genes
    2. Heat from the body is not lost to the surrounding through sweating because evaporation of sweat will below; as air is already saturated
    3. hypothalamus
  1.  
    1. Entamoeba Histolytica
    2. Caudidaalbicans
  1.  
    1. ability of the body to recognize foreign antigens and develop mechanisms of destroying them/ ability to resist infections
    2. natural immunity is inborn/ inherited/ passed from parents to off springs while acquired immunity is obtained in life( can only score 2 mks or zero)
    3. Tuberculosis/ Poliomyelitis/ Diptheria (mark the first to apper)
  1.  
    1. green plants →grass hopper→lizard →domestic cat
      Green plants →mice→snakes→hawks
      Green plants→mice→snakes→domestic cat
    2. most plants will die/ dry ; some animals may starve to death
  1. Acts as valves that close and/or open various parts of the canal/ controls food movements in alimentary canal by acting as valves
  1.  
    1. A- condensation
      B- Hydrolysis
    2. sucrose
    3. glycosidic
  1.  
    1. tannins – tanning hides and skin
    2. colchicines – cause polyploidy
    3. quinunine- used as an anti-malaria drug
  1. thin cell wall; has large air spaces
  1.  
    1. 4.0 – 0.04/ 0.04 × 100 = 90%
    2. oxygen concentration reduces because it is used in respiration to produce energy ; carbon iv oxide increases greatly because it is produced during respiration as a by-product ; nitrogen gas concentration remained constant because it is neither used or produced by the body
  1.  
    1. change in body form during the life cycle of an organism
    2. in larvae stage there is a vigorous feeding; hence the insects obtain enough nutrients/ food
  1.  
    1. cohesion- water molecules cling to each other maintaining continuous column of water/ preventing the break of water column
    2. adhesion- water molecules cling to the sides of xylem walls
  1.  
    1. to breakdown the sucrose solution to simple sugars
    2. non- reducing sugar/ disaccharide
    3.  
      1. starch
      2. glycogen
  1. Cells are loosely arranged; to facilitate air circulation Cells have moist surfaces; to dissolve respiratory gases
  1.  
    1. ultrafiltration- to remove urea/ nitrogenous wastes/ toxic / harmful substances from the blood stream
    2. selective re- absorption- to return useful substances/ glucose and amino acids into the blood stream
  1. identity- ribonucleic acid
    Reason- presence of organic base uracil
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