Final answer:
Cells maintain membrane fluidity through a process called homeoviscous adaptation, where they adjust membrane fatty acid composition in response to temperature changes to ensure proper function and homeostasis.
Step-by-step explanation:
Cells can remodel their membranes to preserve fluidity in a process known as homeoviscous adaptation. Membrane fluidity is crucial for cellular functions such as nutrient transport, signaling, and maintaining homeostasis. To adapt to changes in temperature, poikilothermic organisms adjust the fatty acid composition of their cell membranes. For example, in colder environments, they increase unsaturated fatty acid content, which prevents the membrane from becoming too rigid. Conversely, in warmer temperatures, they increase saturated fatty acid content to prevent the membrane from becoming too fluid.
Membrane fluidity also facilitates the incorporation of larger food objects into the cell and allows for efficient diffusion of nutrients. The fluid mosaic model of cell membranes describes how proteins and lipids move within the membrane, maintaining its fluid nature while also protecting the integrity of the cell.