Read the following statements and choose the option which is true for them

a. Simple diffusion in organisms is a slow process

b. Gaseous exchange in plants occurs only by simple diffusion

c. Facilitated diffusion requires transporters

d. Facilitated diffusion shows uphill movement of molecules

Solution:

Let's analyze each statement:

a. Simple diffusion in organisms is a slow process: True. Simple diffusion is a passive process that depends on the concentration gradient, permeability of the membrane, and size/solubility of the molecules. It is generally a slow process, especially over long distances.

b. Gaseous exchange in plants occurs only by simple diffusion: True. The actual exchange of gases (like CO2 and O2) across the cell membranes of plant cells occurs via simple diffusion, moving down their respective concentration gradients. While stomata regulate the overall flow, the fundamental mechanism of exchange at the cellular level is simple diffusion.

c. Facilitated diffusion requires transporters: True. Facilitated diffusion is a type of passive transport that requires specific membrane proteins (transporters or channel proteins) to facilitate the movement of molecules across the membrane.

d. Facilitated diffusion shows uphill movement of molecules: False. Facilitated diffusion, like simple diffusion, is a passive process. It occurs down a concentration gradient (from a region of higher concentration to a region of lower concentration), not uphill (against the concentration gradient). Uphill movement requires active transport.

Based on the analysis, statements a, b, and c are correct, while statement d is incorrect. Therefore, option (1) is the correct choice.