The presence of cholesterol in the plasma membranes of some animal cells . The presence of cholesterol in the plasma membranes of some animal cells . enables the membranes to stay fluid when cell temperature drops enables the cell to remove hydrogen atoms from saturated phospholipids enables the cell to add hydrogen atoms to unsaturated phospholipids reduces mutations to genetic material inside the cell makes the cell membrane less flexible, allowing it to sustain greater intracellular pressure

The presence of cholesterol in the plasma membranes of some animal cells enables the membranes to stay fluid when cell temperature drops.

Explanation:

Cholesterol is an essential lipid in the basic structure of cell membranes. The membranes must have a fluid structure so that the proteins integrated in them can move ''horizontally'' to interact with their ligands and with other proteins. With excess saturated fat the membranes become rigid, but only with the necessary unsaturated fat the membranes are extremely fluid, and very sensitive to changes in temperature. Cholesterol stabilizes the structure of the membranes; preventing the collapse and crystallization between lipid chains that would lead to loss of fluidity and excessive rigidity in the membrane. By decreasing the temperature; as temperatures drop, fluidity decreases, an effect that partially counteracts the presence of cholesterol.

a community that experiences major changes undergoes progress

this would be a math