Final answer:
If new cells were consistently smaller than their parent cells, it could lead to issues in cellular function and replication overtime. Cell size is limited due to the critical surface area-to-volume ratio that affects nutrient absorption and waste removal.
Step-by-step explanation:
If new cells were smaller than the original cells, it could result in problems such as inefficient waste excretion or the cell taking on water until it bursts. The limitation of cell size is a critical factor in cellular efficiency and function. The surface area-to-volume ratio is key; as a cell grows, the surface area does not increase at the same rate as the volume, leading to limitations in nutrient absorption and waste removal. Additionally, cells might develop adaptations such as foldings of the cell membrane, becoming flat or thin, or developing organelles to become more efficient. However, there is also a lower limit to how small a cell can be, which is determined by the cell's ability to house the necessary components and functions. In organisms like diatoms, when cells divide, one daughter cell usually inherits a slightly smaller cell size, which over time leads to a decrease in average cell size until a critical minimum triggers sexual reproduction to reset the size.
Small cell size is advantageous for quick diffusion rates and efficiency, as seen in prokaryotes. Large cell size could potentially house more organelles and conduct more complex tasks as seen in eukaryotic cells. Nonetheless, the efficiency of diffusion remains paramount, setting a natural precedent for limiting cell size.