Which statement correctly describes why cells are so small? a) when cells are small the movement of food and waste can be efficiently handled by the cell membrane b) when cells are small they can adapt their shape more easily to fulfill their specific function c) when cells are small their internal parts can better support the cell membrane d) when cells are small they can easily work together to form tissue

a) when cells are small the movement of food and waste can be efficiently handled by the cell membrane

Explanation:

Cells need to get their nutrients and waste in and out of their cell membrane every quickly. Cells are hard workers anyway! The other options also don't make much sense. The cell shape doesn't mean much to their function, and size doesn't impact shape. The cell's internal parts (mitochondria, vacuole, etc) don't support the cell membrane, they have their own functions to focus on. Cells don't work together in tissue but they can interact with each other when needed.

The statement (a) correctly describes that why cells are so small.

Explanation:

Cells are formed of cytoplasm enveloped by a phospholipid bilayer. In the cells of plants, a supplementary cell wall also prevails. The cytoplasm accommodates various metabolic activities that need a spontaneous supply of nutrients. During the same time, metabolic wastes originate from these reactions, which are required to be eradicated. All this uptake and discard of nutrients and waste components occurs by mediation across the cell membrane via passive, active, or facilitated transport.  

In the absence of any circulatory system, these cells depend entirely on the process of diffusion through the membrane. The brisk interchange of molecules can only take place if diffusion occurs over brief distances. Thus, this rate of uptake of nutrients within the cells and discarding of wastes into the external surroundings hugely relies upon the cell surface, which is restricted by the cell membrane. Thus, surface area of the cell is one of the limiting factors to monitor the rates of diffusion of these molecules. Therefore, when the cells are small, their wastes and food can be handled effectively by the cell membrane.