Science (086) — AI-generated practice question

Blood acts as the crucial link between the respiratory and excretory systems in the following ways:

Link with the Respiratory System:
Blood transports oxygen (carried by red blood corpuscles/haemoglobin) from the lungs to all body cells, and carries carbon dioxide (dissolved in plasma) from the cells back to the lungs for removal. Without this transport, gas exchange in the respiratory system would be purposeless.

Link with the Excretory System:
Blood carries nitrogenous wastes such as urea and uric acid (dissolved in plasma) from the body cells to the kidneys, where they are filtered out and excreted as urine. Without blood transporting these wastes, the excretory system cannot function.

Source: Chapter 5, Sections 5.4.1 and 5.5.1

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• Examiners expect you to name the specific substances transported — oxygen, CO₂ for respiration; nitrogenous wastes (urea/uric acid) for excretion. Vague answers like "waste materials" alone lose marks.
• Mentioning that RBCs carry O₂ and plasma carries CO₂ and nitrogenous wastes shows textbook accuracy and earns full credit.
• The question has two parts (respiratory + excretory); address both clearly for all 3 marks.