Biology · Cell: The Unit of Life · NEET
A leucoplast is one of the three plastid types (the others are chloroplast and chromoplast). It is colourless because it has NO pigment - no chlorophyll and no carotenoid. Its job is not colour or photosynthesis; its job is to STORE food. Leucoplasts have varied shapes and sizes and are found in plant cells that store nutrients, like roots, tubers and seeds. For NEET, just remember: leucoplast = colourless + storage.
All three are leucoplasts (colourless, storage). They differ only in WHAT they store. Amyloplast stores carbohydrates as starch (example: potato). Elaioplast stores oils and fats. Aleuroplast stores proteins. So the type is decided by the stored food. NEET loves testing exactly this three-way match, so memorise: amylo->starch, elaio->oil/fat, aleuro->protein.
The amyloplast stores starch. The chloroplast can make sugar during photosynthesis and may hold temporary starch, but the dedicated STORAGE plastid for starch is the amyloplast. NCERT gives potato as the classic example. If a NEET question asks 'plastid that stores starch/carbohydrate', the answer is amyloplast.
Aleuroplast stores PROTEIN, not oil. Oil and fat are stored by the ELAIOPLAST. Trick: 'elaio' sounds like 'oil-io' -> oil. 'Aleuro' relates to aleurone (the protein-rich outer layer of seeds like wheat) -> protein. This exact swap (oil vs protein) is a common NTA trap, so lock it in.
No. Leucoplasts are COLOURLESS and store food (starch, oil, protein). Chromoplasts are COLOURED (yellow, orange, red) because they contain fat-soluble carotenoid pigments like carotene and xanthophyll. So chromoplast = colour pigment, leucoplast = colourless storage. If a question says a plastid 'stores xanthophyll', that is a chromoplast, NOT a leucoplast.
Yes, plastids can change from one type to another under the right conditions - for example, when a potato (rich in amyloplasts) is exposed to light it turns green as leucoplasts develop into chloroplasts. This interconversion is why all three are grouped as 'plastids'. NEET rarely asks the mechanism, but knowing they interconvert helps you avoid treating them as totally separate organelles.
Match List I with List II. List I: A. Nucleolus B. Centriole C. Leucoplasts D. Golgi apparatus List II: I. Site of formation of glycolipid II. Organisation like the cartwheel III. Site for active ribosomal RNA synthesis IV. For storing nutrients
The plastid that stores xanthophyll is known as __________.
Try the real previous-year questions from this chapter — each with the answer and a full solution.
Leucoplasts store food (nutrients). Depending on the type, they store starch (amyloplast), oils and fats (elaioplast), or proteins (aleuroplast).
The amyloplast stores starch (carbohydrate). NCERT gives the potato as the example.
No. Leucoplasts are colourless because they have no pigment (no chlorophyll, no carotenoid). Coloured plastids are chloroplasts (green) and chromoplasts (yellow/orange/red).
Elaioplast stores oils and fats; aleuroplast stores proteins. Do not swap them - this is a common NEET trap.
NEET repeatedly tests the three-way match (amyloplast-starch, elaioplast-oil, aleuroplast-protein) and the trap that leucoplasts store food but do NOT store pigments like xanthophyll.
