Final answer:
Membrane fluidity is influenced by temperature and fatty acid composition. Higher temperatures and unsaturated fatty acids increase fluidity, while lower temperatures and saturated fatty acids decrease fluidity.
Step-by-step explanation:
The subject of this question is Biology. The concept being discussed is membrane fluidity and its impact on membrane durability and permeability. Fluidity in the membrane is influenced by factors such as temperature and the composition of fatty acids. Higher temperatures and the presence of unsaturated fatty acids increase membrane fluidity, while lower temperatures and the presence of saturated fatty acids decrease fluidity.