PlaMids are both region or species specific. These are as follows
(i) Proplastids These are colourless, rounded but amoeboid plastid precursors, found in meristematic and newly formed cells of plants. It has a double membrane envelope that surrounds a colourless matrix, containing DNA, ribosomes and reserve food. A few vesicles and lamellae also occur in the matrix.
(ii) Leucoplasts These are colourless plastids that occur in non-green plant cells commonly near the nucleus. They are as follows
(a) Amyloplasts These leucoplasts store starch, e.g., Tuber of potato, grain of rice and wheat.
(b) Elaioplasts These store fats, e.g., Rose.
(c) Aleuroplasts They are protein storing plastids, e.g., Castor endosperm.
(iii) Chromoplasts These are non-photosynthetic coloured plastids which synthesise and store carotenoid pigments. They appear, orange, red or yellow in colour. These mostly occur in ripe fruits (tomato and chillies) carrot roots, etc.
(iv) Chloroplasts These are photosynthetic plastids, which are green in colour and found in the
leaves of all green plants. They have lamellae organised in the form of grana.