Compare and contrast passive transport system (like cnidarian) with active transport systems such as the human circulation system.

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jerichorayel eNotes educator| Certified Educator

Their main similarities are they are both methods of transport. They are capable of transferring materials from one area to another in any part of the organism where it is needed. Generally active and passive transport happen in the membrane layer of the cells where there is change in gradient in the separated environments. The point of comparison is on how these both methods work. 

Active transport: uses energy (ATP) to pump proteins against the concentration gradient. There are two types of active transport: the primary and the secondary active transports. Primary active transport directly uses ATP for its function. An example of which is the Sodium-Potassium pump. The secondary active transport uses the molecules activated by the ATP - indirect consumption of ATP to perform a specific task. 

Passive transport does not use energy instead it is a movement of molecules with the concentration gradient in order to maintain equilibrium in the cells. The types of passive transport are diffusion, facilitated diffusion, filtration, osmosis.