Diffusion is the movement of a molecule from an area of higher concentration to an area of lower concentration.

True or False?

Choice A rationale: Locates the specimen is incorrect because the fine adjustment knob does not help to find the specimen on the slide, but rather to adjust the focus of the specimen. The fine adjustment knob is a small knob that is located on the side of the microscope, next to the coarse adjustment knob. The fine adjustment knob is used to make small changes in the distance between the objective lens and the specimen, which improves the sharpness of the image.

Choice B rationale: All of the answer choices are correct is incorrect because only one of the answer choices is correct. The fine adjustment knob only fine-tunes the focus of the specimen, not locates the specimen or the focus plane.

Choice C rationale: Locates the focus plane is incorrect because the fine adjustment knob does not help to find the focus plane, but rather to adjust the focus of the specimen. The focus plane is the plane that is perpendicular to the optical axis of the microscope and passes through the focal point of the objective lens. The focus plane is where the specimen is in focus and the image is clear.

Choice D rationale: Fine-tunes the focus is correct because the fine adjustment knob is used to fine-tune the focus of the specimen, which means to make small adjustments in the focus to obtain the best image quality. The fine adjustment knob is used after the coarse adjustment knob, which is used to bring the specimen into approximate focus.

Choice A rationale: Diffusion is correct because it is the passive movement of molecules from an area of high concentration to an area of low concentration. Small lipid soluble molecules can easily cross the plasma membrane by diffusing through the hydrophobic core of the phospholipid bilayer.

Choice B rationale: Filtration is incorrect because it is the process of separating solid particles from a fluid by passing it through a porous medium. Filtration does not involve the plasma membrane, and it does not depend on the solubility of the molecules.

Choice C rationale: Osmosis is incorrect because it is the diffusion of water across a selectively permeable membrane. Osmosis does not apply to lipid soluble molecules, which are not water molecules.

Choice D rationale: Active transport is incorrect because it is the movement of molecules across a membrane against their concentration gradient, which requires energy and transport proteins. Active transport does not depend on the solubility of the molecules, and it is not a passive process.

Choice E rationale: Pumping is incorrect because it is a type of active transport that involves the use of specific pumps to move ions or molecules across a membrane. Pumping does not apply to lipid soluble molecules, which are not ions or polar molecules.