Digestion

Core Concepts ('S' Pass):

• Define: What is digestion?

• List: Name the main organs of the digestive tract in order, starting from the mouth.

• Identify: Which enzyme begins the digestion of starch in the mouth?

• Name: What are the final end products of protein, carbohydrate, and lipid digestion?

• Recall: In which organ does most of the chemical digestion and absorption of food occur?

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Understanding & Application ('C' Pass):

• Explain: What is the role of the epiglottis during swallowing?

• Describe: Explain the importance of bile in the digestion of fats. Where is it produced?

• Compare: State two ways the structure of the small intestine is adapted for efficient absorption of nutrients.

• Explain: Why is the inner wall of the stomach not digested by the pepsin enzyme and hydrochloric acid it contains?

Analysis & Higher-Order Thinking ('B' / 'A' Pass):

• Analyse: Trace the journey of a starch molecule from a piece of bread, describing its chemical digestion and absorption, until it is stored in the liver. Name the key enzymes and locations.

• Justify: Why is faeces not considered an excretory product, even though it is eliminated from the body?

• Synthesize: A person has their gall bladder removed. How would this affect their digestion, and what dietary advice would you give them?

O/L Exam Tip: Focus on the "enzyme-substrate-product" relationship for carbohydrates, proteins, and lipids in different parts of the digestive tract. Be prepared to describe the adaptive features of the small intestine for absorption.

Respiration

Core Concepts ('S' Pass):

• Define: What is cellular respiration?

• Identify: What is the main gas taken in during inspiration and the main gas removed during expiration?

• Name: What are the tiny air sacs in the lungs where gas exchange occurs?

• Recall: What is the main energy-carrying molecule produced during respiration?

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Understanding & Application ('C' Pass):

• Describe: Explain the roles of the intercostal muscles and the diaphragm during inspiration (inhalation).

• Compare: What are two main differences between aerobic and anaerobic respiration?

• Explain: List three features that make the alveoli an efficient respiratory surface.

• Relate: What happens to the lactic acid that builds up in muscles during strenuous exercise?

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Analysis & Higher-Order Thinking ('B' / 'A' Pass):

• Analyse: Explain how carbon monoxide from cigarette smoke affects the oxygen-carrying capacity of the blood.

• Justify: Why is aerobic respiration considered much more efficient than anaerobic respiration?

• Synthesize: Trace the path of an oxygen molecule from the air outside the body to a muscle cell where it is used in respiration.

Excretion, Circulation, Coordination & Homeostasis

Core Concepts ('S' Pass):

• Define: What is excretion? Name the main nitrogenous waste product in human urine.

• Identify: Name the four chambers of the heart.

• Name: What are the three main types of blood vessels?

• Define: What is a reflex action?

• Define: What is homeostasis?

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Understanding & Application ('C' Pass):

• Describe: Briefly outline the three main processes of urine formation in the nephron.

• Explain: Why is the human circulatory system called a "double circulatory system"?

• Compare: What is the main functional difference between a sensory neuron and a motor neuron?

• Explain: Describe the roles of insulin and glucagon in maintaining blood sugar homeostasis.

• Relate: Describe one function of the cerebellum and one function of the medulla oblongata.

Analysis & Higher-Order Thinking ('B' / 'A' Pass):

• Analyse: Explain why a healthy person's urine should not contain glucose, but a diabetic person's might.

• Synthesize: Trace the path of a red blood cell starting from the right atrium, going to the lungs, returning to the heart, and then travelling to the kidneys before returning to the right atrium. Name all chambers, valves, and major blood vessels involved.

• Justify: Explain how the sympathetic and parasympathetic nervous systems have opposite effects on heart rate during a 'fight or flight' situation and subsequent relaxation.

O/L Exam Tip: Understand the concept of feedback loops for homeostasis (especially blood glucose and temperature). For circulation, be able to trace blood flow through the heart, lungs, and body.