Summative Practice 12 – Question 7 & 8 (Form 4 Biology Textbook Exercise and Answer)

Question 7:Explain the effects of stimulant drugs and sedative drugs on the transmission of impulse through the synapse. Answer:• Stimulants such as cocaine prevent the removal of the neurotransmitters that stimulate excitement.• This will produce an intense euphoric feeling followed by depression.• Stimulants also increase impulse transmissions that cause increases in the heartbeat and respiration … Read more

Summative Practice 12 – Question 5 & 6 (Form 4 Biology Textbook Exercise and Answer)

Question 5:Figure 1 shows the cross section of a part of the nervous system.(a) (i) Name structure X.(ii) State the function of structure X.(b) Why is part Y swollen?(c) Complete Figure 1 with neurones involved in a reflex action. Mark the direction of impulse on the neurone.(d) If the spinal nerve is cut at Z, … Read more

Summative Practice 12 – Question 1 – 4 (Form 4 Biology Textbook Exercise and Answer)

Question 1:Compare the functions of the cerebellum and the medulla oblongata. Answer:The cerebellum controls and coordinates body movement as well maintains body balance. The medulla oblongata controls involuntary responses such as peristalsis. Question 2:Define reflex action and state its importance. Answer:Reflex action is defined as a rapid and automatic response without thinking. The ability to … Read more

Formative Practice 12.6 (Form 4 Biology Textbook Exercise and Answer)

Question 1:Name the hormone that is related to the function given. Answer: Question 2:State three characteristics of hormones. Answer:• Secreted by a specialised gland known as the endocrine gland• Required in a small quantity only• Effect/influence period is long Question 3:Compare between the nervous system and the endocrine system. Answer:• The nervous system transmits information … Read more

Formative Practice 12.7 (Form 4 Biology Textbook Exercise and Answer)

Question 1:State the factors that cause a person to contract diabetes insipidus. Answer:The posterior lobe of the individual’s pituitary gland failed to secrete antidiuretic hormone (ADH). Question 2:State two symptoms experienced by people with diabetes mellitus. Answer:Blurred vision and wounds take longer time to heal Question 3:Goitre is a disease that causes the enlargement of … Read more

Formative Practice 12.5 (Form 4 Biology Textbook Exercise and Answer)

Question 1:State the symptoms of Alzheimer’s disease. Answer:The patient forgets easily and loses his/her sense of direction even in familiar places. If the brain degeneration continues, he/she will lose the ability to read, write, eat, walk and speak. Question 2:Explain how drugs affect the coordination of one’s nerves. Answer:Drugs speed up or slow down impulse … Read more

Formative Practice 12.4 (Form 4 Biology Textbook Exercise and Answer)

Question 1:State the sequence of impulse transmission in the knee jerk reflex arc. Answer: Question 2:One example of reflex action is pulling the hand away from a hot object. Define the reflex action and state its importance. Answer:Reflex action is defined as a quick and automatic response that does not involve thinking. Reflex action is … Read more

Formative Practice 12.3 (Form 4 Biology Textbook Exercise and Answer)

Question 1:What is the function of motor neurones? Answer:The motor neurone receives nerve impulses from the relay neurone of the central nervous system and transmits them to an effector such as muscles or glands for an appropriate response. Question 2:Why do synaptic knobs contain a lot of mitochondria? Answer:To generate the required energy needed for … Read more

Formative Practice 12.2 (Form 4 Biology Textbook Exercise and Answer)

Question 1:Explain the role of the brain in body coordination. Answer:The brain receives various types of information from the receptor. It analyses, integrates and links the information together to form a meaningful overview.After the information is processed, appropriate response(s) will be determined and effectors are directed to execute the response(s). Question 2:Compare the functions of … Read more

Formative Practice 12.1 (Form 4 Biology Textbook Exercise and Answer)

Question 1:What is the meaning of response? Answer:Response refers to how an organism reacts after detecting a stimulus. Question 2:Which sensory organ has the mechanoreceptor as a sensory receptor? Answer:Skin Question 3:In your opinion, why is coordination crucial to humans? Answer:Coordination is very important to humans because any changes that occur in the external environment … Read more