NEET BIOLOGY

Detailed explanation-1: -Smaller single-celled organisms have a high surface area to volume ratio, which allows them to rely on oxygen and material diffusing into the cell (and wastes diffusing out) in order to survive. The higher the surface area to volume ratio they have, the more effective this process can be.

Detailed explanation-2: -Seeing that the surface area to volume ratio of cells generally decreases as cells get larger, making the exchange of resources, waster and heat more and more difficult.

Detailed explanation-3: -When a cell’s surface area increases, the amount of substances diffusing into the cell increases. As volume and surface area increase, the volume increases faster, so much so that the surface area available to allow substances in halves each time the cell volume doubles.

Detailed explanation-4: -Explanation: When the cell increases in size, the volume increases faster than the surface area, because volume is cubed where surface area is squared. When there is more volume and less surface area, diffusion takes longer and is less effective.

Detailed explanation-5: -Cells are limited in size by their surface area to volume ratio. That is, their plasma membrane (surface area) must be large enough to import nutrients and excrete wastes for the entire cytoplasm (volume) of the cell. As cells get larger, their surface area to volume ratio increases, which is why cells are very small.