Differentiate between the following pairs of terms based on the clues given in parentheses:

(A) Cell membrane and cell wall (Permeability)

(B) RER and SER (Structure)

(C) Chloroplasts and chromoplasts (Pigments)

(A) Cell membrane: Selectively permeable, i.e., it controls the entry and exit of substances, allowing only specific molecules to pass through.
Cell wall: Freely permeable, i.e., it allows most substances (water, gases, small molecules) to pass through without restriction.

(B) Rough Endoplasmic Reticulum (RER): It has ribosomes attached to its surface, giving it a rough appearance; mainly involved in protein synthesis.
Smooth Endoplasmic Reticulum (SER): Lacks ribosomes on its surface, appears smooth; mainly involved in lipid synthesis and detoxification of the body.

(C) Chloroplasts: Contain green pigment, i.e., chlorophyll, essential for photosynthesis.
Chromoplasts: Contain non-green pigments, responsible for red, yellow, and orange colors in fruits and flowers.