Covers biological coordination systems, contrasting quick electric signals (Nervous System) with sustained chemical messages (Hormones). Emphasis placed on mechanisms like negative feedback (glucose homeostasis) and comparison of coordination methods across animals and plants.
Marking Scheme: Excretion This is the marking scheme for quiz: Excretion Quiz Study guide: Excretion Short Answer Questions 1. State the name of the gas excreted through the lungs and write the balanced chemical equation for its production during cellular respiration. Marks: 2 Gas name: carbon dioxide, CO₂ (1 mark) Balanced chemical equation: C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O (1 mark) 2. What are the two main regions of the kidney? Describe their functions. ...
Quiz: Excretion State the name of the gas excreted through the lungs and write the balanced chemical equation for its production during cellular respiration. What are the two main regions of the kidney? Describe their functions. Explain how urea is produced in the human body. Include a chemical equation. Describe the process of deamination. How does it relate to urea formation? Outline the steps involved in urine formation within a nephron. ...
Respiration Energy from respiration Respiration is the chemical process in cells that releases energy from glucose. Cells use this energy for: muscle contraction; protein synthesis; cell division; active transport; growth; nerve impulses; and maintaining body temperature. Respiration is not the same as breathing. Breathing moves air into and out of the lungs; respiration releases energy in cells. Aerobic respiration Aerobic respiration uses oxygen to break down glucose and releases a large amount of energy. ...
Gas exchange in humans Gas-exchange surfaces A gas-exchange surface needs: a large surface area, providing many sites for diffusion; a thin surface, giving a short diffusion distance; a good blood supply, maintaining concentration gradients; and good ventilation, replacing air and maintaining concentration gradients. Alveoli provide these features. Their large total surface area gives many diffusion sites, their walls are one cell thick, capillaries carry away oxygen and bring carbon dioxide, and ventilation continually refreshes the air. ...