level: Circulatory system
Questions and Answers List
level questions: Circulatory system
Question | Answer |
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Why do multicellular organisms need a transport system | - they have a large surface area to volume ratio - they have a higher metabolic rate - they are very active, so a large number of cells are all respiring quickly, therefore they need a constant supply of oxygen and glucose |
Define single circulatory system | blood only passes through the heart once for each complete circuit of the body |
Define double circulatory system | blood passes through the heart twice for each complete circuit of the body |
Define closed circulatory system | blood is enclosed inside blood vessels. Example: in fish |
Define open circulatory system | blood isn't enclosed in blood vessels all the time. Instead, it flows freely though the body cavity. Example: in insects |