Question

Name various types of plastids present in a cell.

Answer 1

Hint:The term plastid was given by Haeckel. These are light microscopic structures found in plant cells and some protists, e.g. Euglenoids and diatoms.

 Complete answer:
>On the basis of their specific functions and pigments present in them, they are classified into two types- leucoplasts and chromoplasts.
>Leucoplasts- These are largest sized colorless plastids that have no grana and chlorophyll. These are found in the parts of the plants that are not exposed to light, e.g. roots, rhizome, seeds, etc. These are involved in the storage of food.
>There are three types of leucoplasts based on the types of food they store:
1. Amyloplasts- These store starch and are found in grains of rice and wheat and potato tubers.
2. Elaioplasts or Oleoplasts- These store fats and are found in seeds of castor, mustard, groundnut, etc.
3. Aleuroplasts or Proteinoplasts- These store proteins and are found in maize grains.
Chromoplasts- These are pigmented plastids that are found in the plant parts that are exposed to light, e.g. leaves, flowers, etc. These are involved in photosynthesis, pollination and dispersal of seeds or fruits.
On the basis of pigments, these are of three types:
>Chloroplasts or autoplastic- These contain chlorophyll and carotenoids and are found in leaves of green plants.
>Phaeoplasts- These contain xanthophylls and fucoxanthin and are found in brown algae.
>Rhodoplasts- These contain red pigment phycoerythrin and are found in red algae.

Note:Chloroplast is the green colored plastid which was discovered by Anton Van Leuwenhoek and the term Chloroplast was given by Schimper. These are the site of photosynthesis in the plants.