Biology P1 Questions and Answers - Nambale Mock Exams 2021/2022

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Instructions to candidates

  1. Write your name and index number in the spaces provided above.
  2. Sign and write the date of examination in the spaces provided above.
  3.  Answer all the questions in this question paper.
  4. All answers must be written in the spaces provided.
  5. This paper consists of 12 printed pages.
  6. Candidates should check the question paper to ascertain that all the pages are printed as indicated and that no questions are missing.
  7. Candidates should answer the questions in English.

For Examiner’s Use Only

Question Number

Maximum Score

Candidate’s Score

1- 31

80

 



Questions

  1. Below is an image of a biological vector. Use it to answer questions that follow.
    1 jahdgtay
    1. Identify the parasite transmitted into human blood by the organism. (1 mark)
    2. Name the blood cells that are destroyed by the parasite in (a) above. (1 mark)
    3. State one biological method used to eradicate the larvae of this organism. (1 mark)
  2. Give the structural adaptations of the following in an insect pollinated plant.
    1. Pollen grain. (1 mark)
    2. Stigma. (1 mark)
  3. A certain plant was found to have the following features
    • Parallel venation of leaves.
    • Sheath like petiole.
    • Flower parts in multiple of three.
      1. Name the class to which the plant belongs. (1mark)
      2. Suggest the expected arrangement of vascular bundle in the stem of the plant. (1mark)
  4. In an experiment, the rate of gaseous was determined and recorded as shown in the table below. Using these figures, suggest which plant gaseous structure were responsible for these figures

    Structure

    Gaseous exchange in %

    A

    Approximately 97

    B

    Approximately 2.5

    C

    Approximately 0.5

    A………………………………………………………………………………………….. (1mark)
    B……………………………………………………………..…………………………….. (1mark)
    C………………………………………………………………………………………….…(1mark)
  5. The diagram below shows an experiment set up using a seedling enclosed in a desk box with a hole on one side at the beginning of the experiment and after five days of growth.
    5 jkabda
    1. What type of response is shown by the above shoot? (1 mark)
    2. State two observable changes which took place in the seedling after five days of growth. (2 marks)
    3. Account for the observable changes in (b) above. (2 marks)
  6.                              
    1. State the reason for the following adaptation of the xylem vessels (2marks)
      1. Narrow lumen
      2. Lack of cross wall
  7. Name the organism that causes each of the following diseases.
    1. Gonorrhea (1mark)
    2. Amoebic dysentery (1mark)
  8.                                            
    1. What is a species? (1mark)
    2. A horse and a donkey can interbreed to give rise to an offspring, the mule. However they are still considered to belong to different species. Explain (1mark)
  9. The diagram below represents a set up to investigate the conditions necessary for seed germination. The set up was left for 5 days.
    9 jhgauda
    1. What conditions were being investigated in the experiment? (2marks)
    2. Explain the role of water during seed germination. (2marks)
  10. Explain what happens to excess amino acids in the liver of humans. (2marks)
  11. State the branch of Biology that deals with: (2 marks)
    1. Study of birds
    2. Study of the chemical composition of organisms
  12. The apparatus below illustrates breathing in a mammal.
    12 hayda
    1. State the organs represented by:
      1. Rubber (1 mark)
      2. Rubber plug. (1 mark)
    2. Explain what happens if the rubber plug is pulled in the direction shown by the arrow. (2 marks)
  13.                          
    1. Calculate the respiratory Quotient(RQ) from the equation below. (2 marks)
      2C51H95O6 + 145O2 → 102CO2 + 98H2O
    2. Identify with a reason the substrate being respired from the equation above. (1 mark)
  14. The diagram below shows the base sequence of part of a nucleic acid strand. Study it and answer the questions that follow.
    14 jagtdua
    1. With a reason state whether the strand above is from a DNA or RNA molecule. (2 marks)
    2. State two structural differences between DNA and RNA strands. (2marks)
  15. The diagram below shows how food bolus moves along the alimentary canal and intestines.
    15 yafytda
    1. Identify the process illustrated on the diagram. (1 mark)
    2. Briefly explain how the movement of food bolus from position 1 to position 2 in the diagram above is achieved. (2 marks)
  16. A person was complaining of thirst most of the times. A sample of the patient’s urine was found to contain a lot of sugar.
    1. Name the hormone the person’s body was deficient of. (1 mark)
    2. Which disease was the person likely to be suffering from? (1 mark)
  17. Name two mechanisms that hinder self fertilization in flowering plants. (2 marks)
  18. The diagram below represents a cross section of a plant organ. Study it and answer the questions that follow.
    18 iaygugda
    1.                              
      1. From which plant organ was the section obtained from? (1 mark)
      2. Give a reason for your answer in (a) (i) above. (1 mark)
    2. What is the function of the part labeled C? (1mark)
  19.                              
    1. What is meant by vestigial structures? (1 mark)
    2. Give two examples of vestigial structures in humans. (2 marks)
  20. Julie observed 8 onion epidermal cells across a field of view of a light microscope. The field of view was 4 mm in diameter; calculate the average of the cells in micrometres. (2 marks)
  21. State the use of the following plant waste products to humans. (2 marks)
    1. Papain........................................................................................................................................................
    2. Colchicine................................................................................................................................................
  22. A student dropped a small piece of fresh liver in a beaker containing hydrogen peroxide. A lot of fizzling and froth was observed.
    1. Name the gas produced. (1 mark)
    2. Write the word equation for the reaction above. (1 mark)
  23. Give the functions of the following ecological instruments (2marks)
    1. Seechi disc
    2. Photographic light meter
  24.                          
    1. Explain why fertilization must take place in the fallopian tube but not uterus (1mark)
    2. Explain double fertilization in flowering plants (2marks)
  25. The diagram below represents a mammalian bone of the appendicular skeleton
    25 yatfydta
    1. Name and state the functions of the part labeled M and N. (2marks)
    2. State how the structure X is adapted to its function (1mark)
  26. Use the illustration below to answer questions that follow.
    26 uagytdga
    1. Identify the type of pollution that has such an effect. (1 mark)
    2. State two effects of the type of pollution identified in (a) above to the organism. (2 marks)
  27. The curve below shows the rate of photosynthesis at difficult light intensities
    27 uaygudya
    1. With reference to photosynthesis, give the meaning of the phrase limiting factor. (1mark)
    2. Name the limiting factor between the following points (2marks)
      1. P and Q
      2. R and S
  28. Study the food web below and answer the questions that follow.
    28 ayguygda
    1. Write down a food chain whose all consumers are Arthropods. (1mark)
    2. What would be the short term effects on the habitat if all trout fish were eliminated? (2marks)
  29. The diagram below represents a stage in the development of human foetus
    29 iahuda
    1. State one function of each of the structures labelled A and B. (2marks)
      A ………………………………………………………………………………………………
      B………………………………………………………………………………………………..
    2. Apart from the size of the foetus what else from the diagram illustrates that parturition was about to occur. (1mark)
  30. Explain why growing grass die a few days when salt is sprinkled on it. (2marks)
  31.                        
    1. What is carbonic anhydrase? (1 mark)
    2. State the role of haemoglobin in the transport of carbon (IV) oxide. (2 marks)


MARKING SCHEME

  1. Below is an image of a biological vector. Use it to answer questions that follow.
    1 jahdgtay
    1. Identify the parasite transmitted into human blood by the organism. (1 mark)
      • Plasmodium species//Plasmodium vivax//Plasmodium malariae//Plasmodium ovale//Plasmodium falciparum
    2. Name the blood cells that are destroyed by the parasite in (a) above. (1 mark)
      • Red blood cells//Erythrocytes.
    3. State one biological method used to eradicate the larvae of this organism. (1 mark)
      • Fish feeding on the larvae;
  2. Give the structural adaptations of the following in an insect pollinated plant.
    1. Pollen grain. (1 mark)
    2. Stigma. (1 mark)
  3. A certain plant was found to have the following features
    • Parallel venation of leaves.
    • Sheath like petiole.
    • Flower parts in multiple of three.
      1. Name the class to which the plant belongs. (1mark)
        • Monocotyledonae;
      2. Suggest the expected arrangement of vascular bundle in the stem of the plant. (1mark)
        • Vascular bundles are randomly scattered within the cortex;
  4. In an experiment, the rate of gaseous was determined and recorded as shown in the table below. Using these figures, suggest which plant gaseous structure were responsible for these figures

    Structure

    Gaseous exchange in %

    A

    Approximately 97

    B

    Approximately 2.5

    C

    Approximately 0.5

    A- Stomata;
    B –Lenticels;
    C- Cuticle;
  5. The diagram below shows an experiment set up using a seedling enclosed in a desk box with a hole on one side at the beginning of the experiment and after five days of growth.
    5 jkabda
    1. What type of response is shown by the above shoot? (1 mark)
      • Positive phototropism; Rej. Phototropism alone
    2. State two observable changes which took place in the seedling after five days of growth. (2 marks)
      • Shoot tip/ apex curved towards the source of light; Rej shoot tip bent;
      • Shoot increased in height;
    3. Account for the observable changes in (b) above. (2 marks)
      • Auxins are sensitive to light; auxins migrated to the non-illuminated side; higher concentration of auxins at the non-illuminate side promotes cell division hence cell elongation ; thus rapid growth ; shoot increased in height due to primary growth / rapid mitotic cell division of meristemic cells present in the shoot apex; OWTTE
  6.                              
    1. State the reason for the following adaptation of the xylem vessels (2marks)
      1. Narrow lumen
        • To enhance capillarity of water up the stem
      2. Lack of cross wall
        • To allow continuous flow of materials
  7. Name the organism that causes each of the following diseases.
    1. Gonorrhea (1mark)
      • Neisseria gonorrhea;
    2. Amoebic dysentery (1mark)
      • Entamoeba histolytica ;
  8.                                            
    1. What is a species? (1mark)
      • A group of living organisms that can freely or naturally interbreed to give rise to fertile and viable offspring
    2. A horse and a donkey can interbreed to give rise to an offspring, the mule. However they are still considered to belong to different species. Explain (1mark)
      • The resultant offspring, the mule is infertile
  9. The diagram below represents a set up to investigate the conditions necessary for seed germination. The set up was left for 5 days.
    9 jhgauda
    1. What conditions were being investigated in the experiment? (2marks)
      • Optimum temperature
      • Oxygen
    2. Explain the role of water during seed germination. (2marks)
      • To activate enzyme involved in germination or breaking dormancy
      • it is a reactant in hydrolysis of food
      • act as a solvent/transport medium
      • softens the hard testa /seed coat max 2marks
  10. Explain what happens to excess amino acids in the liver of humans. (2marks)
    • Excess amino acids are deaminated/ the amino group is removed from an amino acid. The amino acid (NH2) is converted into ammonia. The ammonia combines with Carbon (IV) Oxide (in the ornithine cycle which is a series of reactions) resulting in the formation of urea. The carboxyl group is converted to glucose for respiration/glycogen for storage 
  11. State the branch of Biology that deals with: (2 marks)
    1. Study of birds
      • Ornithology;
    2. Study of the chemical composition of organisms
      • Biochemistry;
  12. The apparatus below illustrates breathing in a mammal.
    12 hayda
    1. State the organs represented by:
      1. Rubber (1 mark)
        • Lungs;
      2. Rubber plug. (1 mark)
        • Diaphragm;
    2. Explain what happens if the rubber plug is pulled in the direction shown by the arrow. (2 marks)
      • Explain: The rubber balloon would be inflated as air is sucked in;
  13.                          
    1. Calculate the respiratory Quotient(RQ) from the equation below. (2 marks)
      2C51H95O6 + 145O2 → 102CO2 + 98H2O
      • RQ = volume of CO2 produced = 102 = 0,7
                  volume of O2 consumed    145
    2. Identify with a reason the substrate being respired from the equation above. (1 mark)
      • Lipid; Has an RQ of 0.7;
  14. The diagram below shows the base sequence of part of a nucleic acid strand. Study it and answer the questions that follow.
    14 jagtdua
    1. With a reason state whether the strand above is from a DNA or RNA molecule. (2 marks)
      • DNA; It has the base Thymine;
    2. State two structural differences between DNA and RNA strands. (2marks)
      • DNA

        RNA

        Double stranded

        Single stranded;

        Has Thymine base

        Has base Uracil;

        Has deoxyribose sugar

        Has ribose sugar;

  15. The diagram below shows how food bolus moves along the alimentary canal and intestines.
    15 yafytda
    1. Identify the process illustrated on the diagram. (1 mark)
      • Peristalsis;
    2. Briefly explain how the movement of food bolus from position 1 to position 2 in the diagram above is achieved. (2 marks)
      • Rhythmic contraction and relaxation of circular and longitudinal muscles on the walls of the alimentary canal push the food downwards;
  16. A person was complaining of thirst most of the times. A sample of the patient’s urine was found to contain a lot of sugar.
    1. Name the hormone the person’s body was deficient of. (1 mark)
      • Insulin;
    2. Which disease was the person likely to be suffering from? (1 mark)
      • Diabetes mellitus;
  17. Name two mechanisms that hinder self fertilization in flowering plants. (2 marks)
    • Self sterility; Protandry and protogyny; Hermaphrodite;
  18. The diagram below represents a cross section of a plant organ. Study it and answer the questions that follow.
    18 iaygugda
    1.                              
      1. From which plant organ was the section obtained from? (1 mark)
        • Dicotyledonous stem;
      2. Give a reason for your answer in (a) (i) above. (1 mark)
        • Presence of pith;         lack of root hairs;
    2. What is the function of the part labeled C? (1mark)
      • Translocation;
  19.                              
    1. What is meant by vestigial structures? (1 mark)
      • Structures that in the course of time ceased to function and thus became reduced in size;
    2. Give two examples of vestigial structures in humans. (2 marks)
      • Appendix; Coccyx/ tail; body hair;
  20. Julie observed 8 onion epidermal cells across a field of view of a light microscope. The field of view was 4 mm in diameter; calculate the average of the cells in micrometres. (2 marks)
    • 1 mm= 1000ᶣm              4 mm= 4000ᶣm            Average size = 4000/8; = 500ᶣm;
  21. State the use of the following plant waste products to humans. (2 marks)
    1. Papain- meat tenderizer;
    2. Colchicine- to induce polyploidy in plants;
  22. A student dropped a small piece of fresh liver in a beaker containing hydrogen peroxide. A lot of fizzling and froth was observed.
    1. Name the gas produced. (1 mark)
      • Oxygen;
    2. Write the word equation for the reaction above. (1 mark)
      • Hydrogen peroxide → water + Oxygen; rej chemical equations
  23. Give the functions of the following ecological instruments (2marks)
    1. Seechi disc
      • light penetration in water;
    2. Photographic light meter
      • Light intensity
  24.                          
    1. Explain why fertilization must take place in the fallopian tube but not uterus (1mark)
      • the ovum has a short lifespan of about 24 hours; to enable proper implantation;
    2. Explain double fertilization in flowering plants (2marks)
      • one male gamete nucleus fuses with the functional egg cell; to form a diploid zygote; the other male nucleus fuses with both polar nuclei to form a triploid nucleus(primary endosperm nucleus);
  25. The diagram below represents a mammalian bone of the appendicular skeleton
    25 yatfydta
    1. Name and state the functions of the part labeled M and N. (2marks)
      • M- Acetabulum; articulates with the head of femur forming ball and socket joint.
        N- Obturator foramen; has connective tissues to reduce the weight of the pelvic girdle 
        check spellings.  

    2. State how the structure X is adapted to its function (1mark)
      • X is made of cartilage Can expand to allow widening of the  female pelvic girdle;
  26. Use the illustration below to answer questions that follow.
    26 uagytdga
    1. Identify the type of pollution that has such an effect. (1 mark)
      • Water pollution;
    2. State two effects of the type of pollution identified in (a) above to the organism. (2 marks)
      • Oil soaks the feathers hindering locomotion;
      • Birds remove oil using their beaks swallowing some of the oil causing poisoning;
  27. The curve below shows the rate of photosynthesis at difficult light intensities
    27 uaygudya
    1. With reference to photosynthesis, give the meaning of the phrase limiting factor. (1mark)
      • A factor that influence photosynthesis but is not at its optimum // in short supply

    2. Name the limiting factor between the following points (2marks)
      1. P and Q
        • Light intensity
      2. R and S
        • Temperature
          Acc carbon (iv) oxide concentration
  28. Study the food web below and answer the questions that follow.
    28 ayguygda
    1. Write down a food chain whose all consumers are Arthropods. (1mark)
      • Detritus/algae → Caddis fly larva →  Water scorpion
    2. What would be the short term effects on the habitat if all trout fish were eliminated? (2marks)
      • - Tadpole larva will slightly increase.
        - Detritus plant will decrease
  29. The diagram below represents a stage in the development of human foetus
    29 iahuda
    1. State one function of each of the structures labelled A and B. (2marks)
      A – Has umbilical vein and artery to supply foetus with nutrients and removal of waste
      products; √
      B – Protects embryo from shock/regulate temp. of developing embryo/ suspends and supports embryo;
    2. Apart from the size of the foetus what else from the diagram illustrates that parturition was about to occur. (1mark)
      • Foetus head is turned towards the cervix
  30. Explain why growing grass die a few days when salt is sprinkled on it. (2marks)
    • Salt exerts osmotic pressure on the cells of grass; Water is drawn from the cells by osmosis; the cells loose turgidity/become flaccid; further water loss dehydrates cells ;( hence kills the plant)  max 2 marks.
  31.                        
    1. What is carbonic anhydrase? (1 mark)
      • An enzyme (in red blood cells) that speeds up the reaction  between water and carbon (IV) oxide; to form carbonic acid;
    2. State the role of haemoglobin in the transport of carbon (IV) oxide. (2 marks)
      • It combines with carbon (IV) oxide to form carbaminohaemoglobin which is transported to the lungs;
      • It combines with hydrogen ions from dissociation of carbonic acid (hence acting as a buffer);
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