Answer:
Wheat and corn are common products of tropical plantations.
The membrane is selectively permeable because substances do not cross it indiscriminately. Some molecules, such as hydrocarbons and oxygen can cross the membrane. Many large molecules (such as glucose and other sugars) cannot. Water can pass through between the lipids.
Scientific modeling is a scientific activity, the aim of which is also to make something a particular part or feature of the word easier to recognize, define, quantify, visualize, or even simulate by referencing it to an existing and usually commonly accepted knowledge.