In the following question, a pair of words or phrases is followed by five pairs of words or phrases. Choose the pair that best expresses a relationship similar to that in the original pair.
Diffusion: Passive Transport
A. Exocytosis: Active Transport
B. Facilitated Diffusion: Active Transport
C. Osmosis: Active Transport ****
D. Endocytosis: Passive Transport
E. Sodium/Potassium Pump: Passive Transport
To determine the pair that best expresses a relationship similar to that in the original pair, we need to understand the relationship between "diffusion" and "passive transport."
Diffusion is a type of passive transport where molecules move from an area of higher concentration to an area of lower concentration. In passive transport, substances move across the cell membrane without needing energy input from the cell.
Looking at the options, we need to find a pair where the first term represents a process similar to diffusion, and the second term represents a type of passive transport.
A. Exocytosis: Active Transport
Exocytosis is a process where vesicles fuse with the cell membrane, releasing contents outside the cell. Active transport requires energy input from the cell to transport substances against their concentration gradient. Therefore, this option does not match the relationship in the original pair.
B. Facilitated Diffusion: Active Transport
Facilitated diffusion is a type of passive transport where specific molecules are transported across the cell membrane with the help of transport proteins. Active transport, as mentioned earlier, requires energy input from the cell. Therefore, this option does not match the relationship in the original pair.
C. Osmosis: Active Transport
Osmosis is the passive transport of water across a selectively permeable membrane. Active transport, as mentioned earlier, requires energy input from the cell. Therefore, this option does not match the relationship in the original pair.
D. Endocytosis: Passive Transport
Endocytosis is a process where substances are taken into the cell by engulfing them with the cell membrane. This is a type of passive transport as it does not require energy input from the cell. Although endocytosis is a type of passive transport, it does not represent a similar relationship to diffusion. Therefore, this option does not match the relationship in the original pair.
E. Sodium/Potassium Pump: Passive Transport
The sodium/potassium pump is a process where sodium ions are pumped out of the cell, while potassium ions are pumped into the cell, using energy from ATP. Therefore, this option does not match the relationship in the original pair.
Based on the analysis, none of the given pairs of words or phrases express a relationship similar to that between "diffusion" and "passive transport."