2.11.3 Hormonal Coordination in the Body (Structured Questions)

Question 1:
Diagram 1 shows the location of endocrine glands of a woman.
(a) Name glands R and S in the boxes provided in Diagram 1.

(b) State one function of hormone secreted by glands R and S.

(c) State one effect to the woman if both glands S are removed.

(d) Label with letter X the thyroid gland in Diagram 1.

R: Pituitary gland
S: Ovary

R: Simulates the production of hormone by thyroid gland
S: Control menstrual cycle



2.2.2e Involvement of Systems in Maintaining an Optimal Internal Environment

Internal Environment of Multicellular Organism

  1. The internal environment of a multicellular cell is referring to the medium surrounding the cell.
  2. It consists of blood plasma and interstitial fluid. (also called the extracellular fluid)


Homeostasis is the property of a system, especially a living organism, that regulates its internal environment so as to maintain a stable, constant condition.

Factors Affecting the Internal Environment.

  1. Body temperature
  2. pH value of the blood
  3. Sugar level of the blood
  4. Blood pressure
  5. Osmotic pressure of the blood
  6. Concentration of the oxygen and carbon dioxide in the blood

Importance of Homeostasis

Maintaining a suitable environment for all the enzyme function efficienly, and hence enable all biochemical reactions been carried out at their maximum rate.

Regulation of body temperature

Nervous system Detect changes in body temperature
Integumentary system Produces sweat when the surrounding is hot.
Circulatory system Transports and distributes heat evenly through out the body
Muscular system Shivering to produce heat when the surrounding is cool.

2.11.2 The Human Brain (Structured Questions)

Question 1:
Diagram below shows the structure of a human brain.

(a) Name the parts A and B in the boxes provided in the diagram using the following terms:

(b) State one function of B.

(c) What will happen to a person if area D is injured? What is the effect on man if part D is injured?

(d) Part C controls involuntary action.
Mark (\/) the action which is controlled by part C.


(b) Maintains balance and body posture

(c) Loss of memory


Question 2:
Diagram 1 shows the part of the human brain.

(a) Based on Diagram 1, name parts W and Y in the boxes provided using the following information.

(b) State the function of W and Y.
W: _____________________
Y:  _____________________

(c) What will happen to a person if area X is injured?

(d) In diagram 2, label Q to show the area that controls hearing.


(b) W: Control voluntary actions
   Y: Control involuntary actions

(c) The person will lose control of his muscular coordination and balance.


2.2.2d Organ System

  1. Different organ work together form an organ system.
  2. The human body has eleven different organ system, namely the
    1. Circulatory System
    2. Digestive System
    3. Reproductive System
    4. Endocrine System
    5. Nervous System
    6. Respiratory System
    7. Muscular System
    8. Skeletal System
    9. Excretory System
    10. Lymphatic System (Immune System)
    11. Integumentary System

Circulatory System

Organ: Heart, Blood Vessel
Function: Transport nutrients, gases and wastes to and from cells, helps fight diseases and helps stabilize body temperature and pH to maintain homeostasis.

Digestive System 

Organ: Mouth, Oesophagus, Stomach, Duodenum, Small Intestine, Large Intestine
Function: Breaks down food in the body, into a form that can be absorbed.

Reproductive System

Organ: Males: Testes, penis; Females: Ovaries, uterus, vagina
Function: Reproduce offspring.

Endocrine System

Organ: Pituitary, Thyroid, Adrenal gland, Pancreas, Ovary (female only), testis (male only)
Function: Secrets hormone. Hormones are chemical that play a role in regulating metabolism, growth, development and puberty, and also plays a part in determining mood.

Nervous System

Organ: Brain, Spinal Cord, Peripheral Nerves, Sense Organs
Function: Conduct impulses the the body, spinal cord and brain.

Respiratory System

Organ: Nose, Trachea, Lungs
Function: Allow gas exchange.

Muscular System

Organ: Muscle
  • Initiates heart beat.
  • Working with the skeletal system in movement and locomotion.

Skeletal System

Organ: Bones, Tendons, Ligaments, Cartilage

  • Supports the body.
  • Protects the internal organ.
  • Make red and white blood cells.
  • Plays important role in movement.

Excretory System

Organ: Kidneys, Skin, Lung
Function: Eliminates the waste products of metabolism.

Lymphatic System (Immune System)

Organ: Lymphatic Nodes, Lymphatic Vessels, Spleen, Thymus Galnd

  • Remove the interstitial fluid from tissues.
  • Absorbs and transports fatty acids and fats to the circulatory system.
  • Produces immune cells.

(Images by BruceBlaus shared under the Creative Commons Attribution 3.0 Unported license.)

Integumentary System

Organ: Skin
Function: Protects the body from damage,

2.2.2a Cell

Cell specialisation

  1. Cell specialisation means division of labour among cells. Each type of cell specialises in a specific function.
  2. Importance of Cell Specialisation
    1. Cells can perform specific task with greater efficiency.
    2. Enable multicellular organisms adapt to various environment.

Cell Specialisation in Animal

Cell Function
Red blood cells Transport oxygen
White blood cells Destroy microorganisms. Engulf foreign substance in the blood stream.
Smooth muscle cells Contract and release to produce movement
Nerve cells Transmits nerve impulse

Cell Specialisation in Plant

Cell   Function 
Palisade Mesophyll Cells Carries out photosynthesis
Guard Cells Control the size of the stomata pore to allow gaseous exchange.
Xilem Transport water and mineral salt
Phloem Transport disolved food.

Cell Organisation in Multicellular Organism

Cytology (Cell Biology)

Cytology is an academic discipline that studies cells. It's also known as Cell Biology.


histology is the study of the microscopic anatomy of cells and tissues of plants and animals.

2.11.1 Human Nervous System (Structured Questions)

Question 1:
Diagram 1 shows the structure of a neurone.

(a) Based on the diagram, mark (\/) the type of neurone in the box provided.

(b)(i) Name P.

(b)(ii) State two functions of P.

(c) Name Q.

(d) Diagram 2 shows the pathway of an impulse.

Mark (\/) the location of neurone in Diagram 2.



1. Receives impulse from other neurones.
2. Transmits impulses to the cell body via the dendron.

Effector or muscle fibres


Question 2:
Diagram 1 shows two types of neurones.

(a) Name the type of neurone shown in Diagram 1.
(i) Neurone P:__________

(ii) Neurone Q:__________

(b) Name the structure labelled X at neurone Q.

(c) What is the function of structure X?

(d) Fill in the boxes below with the correct neurone for the impulse pathway.

(a)(i) Neurone P: Sensory neurone
(a)(ii) Neurone Q: Motor neurone

X = axon

X transmits impulses from the cell body to an effector.
For example: A muscle or a gland.


2.2.2 Multicellular Organism

  1. Multicellular organisms are organisms that consist of multiple cells (more than one cell).
  2. Multicellular organisms are more complex than unicellular organisms and hence  need many different types of cell to carry out their life processes.
  3. This can be achieved through cell specialisation and cell organisation.
  4. Examples of multicellular organisms are hydra, spirogyra, weeds, flowering plants, vertebrate and invertebrate animals.