The middle lamella is a layer which cements the primary cell walls of two adjoining plant cells together. ... In a mature plant cell it is the outermost layer of cell wall. In plants, the pectins form a unified and continuous layer between adjacent cells.
Plastids are defined as small organelles present in the cytoplasm of the plant cell. ... Chloroplasts - These kind of plastics are used in the process of photosynthesis as they have green colored pigment.