What is the primary (main) function of lipid molecules in the plasma membrane? - To provide an energy source for most cell activities.

- To provide a substance for enzyme activity in the cell.

- To provide a place to collect and store waste products within the cell.

-To provide a barrier to the movement of substances in and out of the cell.

to provide a barrier to the movement of substances in and out of the cell

Explanation:

Lipid molecules in the plasma membrane form a lipid bilayer which creates a semi-permeable barrier between the inside and the outside of the cell. Water and small molecules can cross the membrane. Other large molecules like ions cannot.

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the correct answer is 4) heat and pressure

metamorphic rocks arise from transformation of existing rocks types, in a process called metamorphism. during metamorphism the original rock(prolith) change into metamorphic rock by heating (150-200c) and pressure of more than 1000 bar. the original rock can be sedimentary, igneous, or existing metamorphic rock.

you can have just about every answer you can think of