- Plastids are present in most of the plant cells and absent in animal cells.
- They are usually spherical or discoidal in shaped and double membrane bound organelles.
- They also have their own DNA and ribosomes.
Plastids are of three types:
- Chloroplasts: These are the green coloured plastids containing chlorophyll. Chloroplasts aid in the manufacture food by the process of photosynthesis.
- Chromoplasts: These are the colourful plastids (except green colour).
- Leucoplasts: These are the colourless plastids.
Chloroplasts trap solar energy and utilise it to manufacture food for the plant.
Chromoplasts impart various colours to flowers to attract insects for pollination.
Lecuoplasts help in the storage of food in the form of starch, proteins and fats.