Who proposed the concept of the unit membrane?

Cut pieces of beetroot do not leave the colour in cold water but do so in hot water. Explain.

Which scientists proposed the $Fluid-Mosaic$ model?

What is the pump in active transport?

The fluidity of membranes in a plant in cold weather may be maintained by

Statement $X$: The cell membrane is the main structural component.
Statement $Y$: It is the site for electron transport and is a selectively permeable membrane.