Which of the following is NOT a type of passive transport in embalming?

Passive transport refers to the movement of substances across cell membranes without the need for energy input, typically following the natural concentration gradient. The correct answer, which identifies a process that is not a type of passive transport, is active transport.

Active transport differs fundamentally from passive transport methods because it requires the expenditure of energy (usually in the form of ATP) to move substances against their concentration gradient. This means that cells can accumulate substances in concentrations higher than their surrounding environment, which is not the case with passive processes.

On the other hand, osmosis, dialysis, and pressure filtration are all considered forms of passive transport. Osmosis specifically pertains to the movement of water across semi-permeable membranes. Dialysis involves the separation of small molecules from larger ones in solution, often used in medical applications to remove waste products from the blood. Pressure filtration utilizes pressure to force a liquid through a filter, enabling the movement of substances without energy use.

Understanding these differences clarifies why active transport is not included in the types of passive transport, making it essential for students studying cellular processes in sciences like embalming.