No matter what the cell type, prokaryotic or eukaryotic, plant or animal, the forms a protective barrier between the exterior environment and the interior of the cell. a) cell wall b) cytoskeleton eliminate c) cell membrane d) glycoproteins

C). cell membrane

The cell membrane is the membrane that can be found in both eukaryotic and prokaryotic cells. It is the cell that separates the interior of the cell from the extracellular environment. It is a protective layer that allows only the selected ions and organic molecules to enter inside the cells and go out of the cell, hence is called as selectively permeable or semi-permeable membrane. This phenomena maintains the concentration of ions and molecules inside the cell and prevents dehydration, cell rupture due to high concentration.

the oldest known insects are believed to live around 400 millions ago as suggested by the fossil records.   some plants having woody stems also evolved during this time.

after the evolution of insects the first four legged species or the tetrapods evolved in shallow freshwater habitats from the intermediate species approximately 397 million years ago. the tetrapods went on conquering the land giving rise to amphibians, reptiles, mammals and birds.

the major split in tetrapods first occurred 340 million years ago branching off from amphibians.

363 million years ago when the carboniferous period began the insects started roaming on land and taking flights, following which the four limbed tetrapods adapted in the terrestrial habitat.