Answer:
Mechanical incompatibility.
Explanation:
Mechanical incompatibility: occurs when species cannot mate because their reproductive structures are incompatible – In animals with internal fertilization, male and female sexual organs may not fit together – For example, snails of species whose shells have left-handed spirals may be unable to copulate successfully.
Mechanical incompatibility of male and female genitalia is common in animals with internal fertilization. However, our knowledge regarding the precise mechanisms is limited.
The bilayer is structured in such a way that it complements the extracellular fluid around the cell as well as the cytoplasm within the cell. This is because the extracellular fluid is hydrophillic, the outside of the membrane protein is hydrophillic, the middle of the membrane protein is hydrophobic, the inside of the cell (the cytoplasm) is hydrophillic and the inside of the membrane protein is hydrophillic.
