Biology

Carbohydrates Chemical Composition Carbohydrates consist of three elements: Element Symbol Typical Proportion Carbon C ~44% by mass Hydrogen H ~6.7% by mass Oxygen O ~49% by mass General formula: C(H₂O)n - water to carbon ratio Types of Carbohydrates Simple Carbohydrates (Monosaccharides and Disaccharides) Single sugar units or two joined together Sweet-tasting, soluble in water Examples: glucose, fructose, sucrose Complex Carbohydrates (Polysaccharides) Long chains of monosaccharide units Not sweet-tasting, insoluble in water Examples: starch, glycogen, cellulose ...

Quiz: Coordination and Response Question 1 Define the term ‘reflex action’. [2] Question 2 The diagram below shows a simple reflex arc. Identify the role of the effector in this process. [1] Explain why reflex actions are important for survival. [2] Question 3 Identify the hormone produced by the pancreas that lowers blood glucose levels. [1] Question 4 Plants respond to their environment through growth movements. Define ‘phototropism’. [2] State the name of the plant hormone responsible for controlling phototropism. [1] Question 5 Compare the structure and function of a sensory neuron and a motor neuron. [4] ...

Marking Scheme: Coordination and Response This is the marking scheme for quiz: Coordination And Response Section 1: Core Syllabus Question 1 An automatic [1] Rapid/unconscious response to a stimulus [1] Question 2 (a) Muscle or gland that carries out the response [1] (b) Protects the organism from harm [1] by reacting quickly without waiting for brain processing [1] Question 3 Insulin [1] Question 4 (a) Growth of a plant [1] in response to light [1] (b) Auxin [1] ...