SPM Form 4/Form 5 Biology Revision Notes

Form 4 Biology

 02 Cell Structure

Objective Questions

  1. Cell Structure and Function 1 (6 Questions) 
  2. Cell Structure and Function 2 (5 Questions) 
  3. Cell Organisation 1 (5 Questions) 
  4. Cell Organisation 2 (5 Questions) 
  5. Cell Organisation 3 (3 Questions) 

03 Movement across Plasma Membrane

Objective Questions

  1. Movement of Substances Across the Plasma Membrane 1 (5 Questions) 
  2. Movement of Substances Across the Plasma Membrane 2 (5 Questions) 
  3. Movement of Substances Across the Plasma Membrane 3 (5 Questions) 
  4. Movement of Substances Across the Plasma Membrane in Everyday Life (5 Questions) 

04 Chemical Composition of Cell Chemical

Objective Questions

  1. Composition of the Cell (3 Questions) 
  2. Carbohydrate (6 Questions) 
  3. Proteins (5 Questions) 
  4. Lipids (3 Questions) 
  5. Enzymes 1 (4 Questions) 
  6. Enzymes 2 (4 Questions) 

    05 Meiosis and Mitosis

    1. Mitosis
    2. Meiosis
    3. Appreciating the Movement of Chromosomes During Mitosis and Meiosis

    Objective Questions

    1. Mitosis 1 (6 Questions) 
    2. Mitosis 2 – (6 Questions) 
    3. Meiosis 1 – (6 Questions) 
    4. Meiosis 2 – (7 Questions) 

    06 Nutrition

    1. The Types of Nutrition
    2. The Concept of a Balanced Diet
    3. Malnutrition
    4. Food Digestion
      1. Digestion in the Mouth and Stomach
      2. Digestion in the Small Intestine
    5. The Process of Absorption and Assimilation of Digested Food
      1. Functions of the Liver and Assimilation
    6. The Formation of Faeces and Defecation
    7. Evaluating Eating Habits
    8. The Importance of a Healthy Digestive System
    9. The Importance of Macronutrients and Micronutrients in Plants
    10. Photosynthesis
    11. The Mechanism of Photosynthesis
    12. Factors Affecting Photosynthesis
    13. Practising a Caring Attitude Towards Plants
    14. The Technology Used in Food Production
    15. Technological Development in Food Processing

    Objective Questions

    1. Balanced Diet (6 Questions) 
    2. Malnutrition (3 Questions) 
    3. Food Digestion (7 Questions) 
    4. Absorption and Assimilation of Digested Food (4 Questions) 

    07 Respiration

    1. The Respiratory Process in Energy Production
    2. The Respiratory Structures and Breathing Mechanisms in Humans and Animals
    3. The Concept of Gaseous Exchange Across the Respiratory Surfaces and the Transport of Gases in Human
    4. The Regulatory Mechanism in Respiration
    5. The Importance of Maintaining a Healthy Respiratory System
    6. Respiration in Plants

    Objective Questions

    1. The Respiratory Process in Energy Production (4 Questions) 
    2. Respiratory Mechanisms in Humans and Animals (7 Questions) 
    3. Gaseous Exchange in Humans (4 Questions) 
    4. The Regulatory Mechanism in Respiration (4 Questions) 
    5. Respiration in Plants (4 Questions) 

    08 Dynamic Ecosystem

    1. The Abiotic and Biotic Components of The Environment
    2. The Processes of Colonisation and Succession in An Ecosystem
    3. Population Ecology
    4. The Concept of Biodiversity
    5. The Impact of Microorganisms on Life
    6. Appreciating Biodiversity

    Objective Questions

    1. The Abiotic and Biotic Components of the Environment (7 Questions) 
    2. The Process of Colonisation and Sucession in an Ecosystem (3 Questions) 
    3. Population Ecology (3 Questions) 
    4. Biodiversity (3 Questions) 
    5. The Impact of Microorganisms on Life (6 Questions) 

    09 Endangered Ecosystem

    1. Human Activities that Endanger the Ecosystem
    2. The Greenhouse Effect and Thinning of the Ozone Layer
    3. The Importance of Proper Management of Development Activities and the Ecosystem

    Objective Questions

    1. Human Activities that Endanger the Ecosystem (7 Questions) 
    2. The Greenhouse Effect and Thinning of the Ozone Layer (6 Questions) 
    3. Proper Management of Development Activities and the Ecosystem (3 Questions)

    Form 5 Biology

    01 Transport

    1. The Importance of Transport System in Multicellular Organisms
    2. The Concept of Circulatory System
      1. Composition of Human Blood
      2. Function of Blood in Transport
      3. Function of Haemolymph in Transport
      4. Types of Circulatory System
      5. Circulatory System in Humans
        1. The Blood Vessels
        2. The Heart
        3. Circulation of Blood in Humans
      6. Regulation of Blood Pressure
    3. Blood Clotting
      1. Mechanism of Blood Clotting
      2. Consequences of Blood Clotting Related Problem
    4. The Lymphatic System
      1. Formation of the Interstitial Fluid and Lymph
      2. Structure of the Lymphatic System
      3. Relationship between the Composition of Blood, Interstitial Fluid and Lymph
      4. Relationship between the Lymphatic System and the Circulatory System
    5. The Role of Circulatory System in Body Defence Mechanism
      1. The Body's Defense Mechanism
      2. Immunity and Immunisation
      3. Types of Immunity
      4. HIV and Body's Defense Mechanism
    6. A Healthy Cardiovascular System
    7. Transport of Substances in Plants
      1. Distribution of Vascular System in Dicotyledon Plants
      2. Vascular Tissue in Plant
      3. Vascular System as a Continuous Tube System
      4. Transport of Organic Substances in Plants
      5. Transport of  Water in Plants
      6. The External Conditions that Affect the Rate of Transpiration

    Objective Questions

    1. The Circulatory System (7 Questions) 
    2. The Mechanism of Blood Clotting (3 Questions) 
    3. The Lymphatic System (4 Questions) 
    4. The Role of Circulatory System in Body Defense Mechanism (4 Questions) 

      02 Support and Locomotion

      1. Support and Locomotion in Humans and Animals
        1. The human skeleton
      2. Appreciate a Healthy Musculoskeletal System
      3. Support System in Plants

      Objective Questions

      1. Support and Locomotion in Humans and Animals 1 (6 Questions) 
      2. Support and Locomotion in Humans and Animals 2 (6 Questions) 
      3. Support System in Plants (4 Questions) 

        03 Coordination and Response

        1. Response and Coordination
        2. The Role of Human Nervous System
        3. The Role of Hormones in Humans
        4. Homeostasis in Humans
          1. The human kidney
          2. The formation of urine
        5. Practising a Healthy Lifestyle 
        6. Plant Hormones
          1. The role of auxins in the tropic movements in plants
          2. Ethylene

        Objective Questions

        1. The Role of the Human Nervous System 1 (6 Questions) 
        2. The Role of the Human Nervous System 2 (6 Questions) 
        3. The Role of Hormones in Humans (7 Questions) 
        4. Homeostasis in Humans (7 Questions) 

        04 Reproduction and Growth

        1. Gamete Formation
        2. Role of Hormones in the Menstrual Cycle
        3. Early Development of Zygote in Humans
        4. Contribution of Science and Technology to Human Reproduction
        5. Sexual Reproduction in Flowering Plants
        6. Growth in Multicellular Organisms
        7. Growth Curve
        8. Primary and Secondary Growth in Plants

        Objective Questions

        1. Formation of Gamete (5 Questions) 
        2. Roles of Hormones in the Menstrual Cycle (5 Questions) 

        05 Inheritance

        1. The Concept of Inheritance Based on Mendel's Experiment
        2. Inheritance
        3. Genes and Chromosomes

        Objective Questions

        Inheritance (10 Questions) 

        06 Variation

        1. Variation in Organisms
        2. Cause of Variation
        3. Be Respectful Towards One Another Despite Variation

        Objective Questions

        Variation (9 Questions)

        4.9.5 Sexual Reproduction in Flowering Plants (Structured Question 1 & 2)

        Question 1:
        Diagram below shows a longitudinal section of the reproductive parts of a flower during fertilization.

        On the Diagram, name the structures J, K, L and M.

        In the space below, draw a section through the ovule, showing all the cells in M.
        (b)(ii) What is the significance of having two K structures in the fertilization?

        In the Diagram, the structure Y has to be kept dormant for future research purposes.
        (i) Explain how Y can be prevented from germinating.
        (ii) If Y is to be germinated, suggest one method to stimulate the germination of Y.

        J : Pollen tube
        K : Male gamete
        L : Ovary
        M : Embryo sac


        - One K/ male gamete fertilizes an egg cell to form a diploid zygote.
        - One more K fuses with two polar nuclei to form a triploid zygote.

        - Keep Y in a dry place
        - Moisture initiates germination

        Spraying a sugary solution onto Y

        3.7.1 The Role of Human Nervous System (Structured Question 1 & 2)

        Question 1:
        Diagram below shows a cross-section of part of the nervous system.

        Name structure P.

        State the function of P.

        Why is Q swollen at the dorsal root?

        Complete the Diagram with the neurones involved in a reflex action. Mark the direction of the impulse movement on the neurones.

        Compare two structures of a sensory neurone and a motor neurone.

        If the spinal nerve is cut off at R, what is the effect on the organ which is connected to it?
        Explain your answer.

        Azmin’s finger accidentally touches a flame.
        Explain briefly how his reflex action functions to avoid the injury.

        P : Spinal cord

        Function of P : Controls reflex actions.

        To place the cell bodies of the afferent neurones.



        The organ is unable to respond. Impulses cannot flow to the effector.

        - The receptor detects heat and triggers an impulse.
        - The impulse is sent to the spinal cord through the afferent neurone.
        - The impulse flows through the afferent neurone which synapses with the interneurone and then synapses with the efferent neurone.
        - The efferent neurone sends an impulse to the effector.
        - The hand is pulled away from flame.


        1.   Ethylene is a small hydrocarbon gas.
        2.   It is a plant hormone which is synthesized during the ripening of fruits.
        3.   Ethylene is responsible for the changes in texture, softening, color, and other processes involved in ripening. 
        4.   Ethylene
        (a) Speeds up the ripening of fruits by stimulating the production of cellulose. Cellulase hydrolyses the cellulose in plant cell walls, making the fruit soft.
        (b) Promotes the breakdown of complex carbohydrate into simple sugar. This make ripe fruit tastes sweeter than an unripe fruit.
        5. Ethylene gas is used commercially to ripen tomatoes, bananas and pears.

        3.6 Plant Hormones

        3.6 Plant Hormones
        1.      Growth of shoots towards sunlight is called positive phototropism.
        2.      Growth of shoots away from sunlight is called negative phototropism.
        3.      In plants, hormones play an important role in growth processes such as seed germination, growth of roots and development of fruits.
        4.      There are many types of plant hormones, such as auxins and ethylene
        Effects of Auxins on Growth Responses
        1.      Auxins are produced in the apical meristems of the shoot tip and the root tip in the cell division zone.
        2.      In the shoot tip, high concentrations of auxins stimulate cell elongation.
        3.      The effect of high concentrations of auxins in the root tip is different from that in the shoot tip. In the root tip, a high concentration of auxins inhibits cell elongation.

        3.4.1 The human kidney

        The Excretory System
        1.   The excretory system plays an important role in homeostasis.
        2.   The primary organs of the excretory system are kidneys.
        The human kidney
        1.   The kidneys filter blood and form urinewhich exits the body through the ureters, urinary bladder and urethra.
        2.Urine is fluid which consists of water, urea and other dissolved wastes.
        3.The human kidney shows three distinct regions
        (a) Cortex(outer light-red region)
        (b) Medulla(inner dark-red region)
        (c) Pelvis(central cavity in which the ureter directly connects to)

        The Nephron
        1.   Each kidney consists of millions of microscopic tubules called nephron.
        2.   A nephron consists of three major parts:
         (a) the glomerulus
         (b) the Bowman’s capsule, and
         (c) renal tubule
        3.   The renal tubule is made up of the
         (a) proximal convoluted tubule
         (b) loop of Henle
         (c) distal convoluted tubule

        3.4 Homeostasis in Humans

        3.4 Homeostasis in Humans
        1.      The internal environment consists of interstitial fluid and blood plasma that constantly bathe the cells.
        2.      Homeostasis is the process of regulating the physical and chemical factors in the internal environment, so that these factors can be maintained in a dynamic equilibrium and optimum condition.
             (a) The physical factors include body temperature, blood pressure and osmotic pressure.
             (b) The chemical factors in the blood include partial pressure of oxygen and carbon dioxide, and the salt and sugar levels.

        2.4.1 Support and Locomotion in Humans and Animals (Structured Question 1 & 2)

        Question 1:
        Diagram I and Diagram II show different positions of a forearm during a movement.

        Complete Diagram I by drawing the triceps muscle which is involved in the movement of the forearm.

        State one adaptive characteristic of tissue R shown in Diagram I which helps in the movement of the forearm.

        Explain the action of the muscles which cause the movement of the forearm in Diagram II.

        Diagram III shows a joint at the knee.

        Explain the health problem normally faced by an old person when tissue P is impaired.

        An athlete must do a warming up exercise before starting an event.
        Explain why.


        Strong/ tough/ non-elastic tissue

        When the biceps relaxes and the triceps contracts, the radius and ulna are pulled downwards and the forearm is straightened.

        - An old person will suffer from osteoarthritis.
        - The wear and tear of the cartilage is due to ageing.
        - The repetitive use of the joints over the years irritates and inflames the cartilage.

        - Eventually, the cartilage begins to degenerate and this causes friction between the bones, leading to pain and restriction of joint mobility.

        - Warming up exercise is needed so that the heart rate increases. This enables oxygen in the blood to travel faster. The capillaries dilate and let more oxygen travel in the blood.

        - Warming up exercise also increases the temperature in the muscles. It loosens up the muscles and joints. This removes lactic acid, lets the muscle fibres have greater extensibility and elasticity and increases the force and contraction of the muscles.

        2.1.1 The Human Skeleton

        The Human Skeleton
        1.      Human skeleton consists of two main parts: axial skeleton and appendicular skeleton
        2.      The axial skeleton consists of the skull, vertebral column, ribs and sternum.


        Ribs and the sternum

        Vertebral column

        Cervical vertebrae

        Thoracic vertebrae

        Lumbar vertebrae

        1.8.2 Lymphatic System (Structured Question 1 & 2)

        Question 1:
        Figure below shows part of the circulatory system and the lymphatic system in the human body.

        What is fluid V? [1 mark]

        What happens to the components of fluid V when it passes through the lymph node? [1 mark]

        Fluid V originates from the blood.
        Describe how fluid V is formed from the blood. [2 marks]

        State one difference between fluid V and the blood. [1 mark]

        A part of vessel T is blocked.
        Explain its effect on the system in the Figure. [2 marks]

        Vessel T in the leg is blocked.
        What would happen to the leg? [1 mark]

        The blood circulatory system and the lymphatic system function to maintain the composition of the tissue fluid.
        Explain how the composition of the tissue fluid is maintained by stating the substances transported by the blood circulatory system and the lymphatic system. [3 marks]

        Fluid V = Lymph

        Toxic substances and pathogens are neutralized/ destroyed.

        Blood plasma diffuses from the capillaries. The tissue fluid formed diffuses into the lymphatic vessels.

        Fluid V does not have erythrocytes whereas blood has erythrocytes. Fluid V is clear yellowish whereas blood is red in colour.

        Interstitial fluid fails to return to the blood circulatory system. Tissue fluid accumulates in the spaces between the cells.

        The leg will be swollen.

        Dissolved substances such as glucose and amino acids are transported in the blood circulatory system entering the body tissues forming tissue fluid. Fatty acids and glycerol are transported by the lymphatic system into the blood circulatory system. Some of the contents of the tissue fluid enter the lymphatic system and some enter the blood circulatory system at the ends of the venules.