EVERYDAY SCIENCE

Detailed explanation-1: -The cell wall is fully permeable to smaller molecules with the size of 30-60 kDa. The membrane is selectively permeable and controls the movement of the substance into and outside the cell. Functions include protection from the external environment.

Detailed explanation-2: -Prokaryotic cells lack a nucleus and membrane-bound structures.

Detailed explanation-3: -Animal cells simply have a cell membrane, but no cell wall.

Detailed explanation-4: -Animal cells do not have cell wallsbecause they do not need them. Cell walls, which are found in plant cells, maintain cell shape, almost as if eachcell has its own exoskeleton. This rigidity allows plants to stand upright without the need for bones .