Plastids are double-membrane organelle which are found in the cells of plants and algae. Plastids are responsible for manufacturing and storing of food. These often contains pigments that are used in photosynthesis and different types of pigments that can change the color of the cell.Plastids

Common Plastids –

  • Chloroplasts
  • Chromoplasts
  • Gerontoplasts
  • Leucoplasts

Types of PlastidsTypes of PlastidsChloroplastsChloroplasts are the most known plastids which are responsible for photosynthesis. These are covered with thylakoids where the process of photosynthesis occurs.

Chromoplasts– is a name given to an area for all the pigments to be kept and synthesized in the plant. These can be usually found in flowering plants, aging leaves and fruits. Chloroplasts convert into chromoplasts. Chromoplasts are carotenoid pigments that allow different colors that you see in leaves and fruits. The main reason for its structure and the color for attracting pollinators.

Gerontoplasts – These are basically chloroplasts that goes with the aging process.  Geronoplasts refers to the chloroplasts of the leaves that helps the beginning to convert into different other organelles when the leaf is no longer using photosynthesis usually in autumn month.

Leucoplasts – These are the non-pigmented organelles which are colorless. They are usually found in most of the non-photosynthetic parts of the plant like roots. They acts as a storage sheds for starches, lipids, and proteins depending on the needs of plant. They are mostly used for converting amino acids and fatty acids.

Leucoplasts are of three types:

  • Amyloplasts – Amyloplasts are greatest among all three – Amyloplasts, proteinoplasts and elaioplasts and are easily charged with storing starch.
  • Proteinoplasts – Proteinoplasts helps in storing the proteins that a plant needs and can be typically found in seeds.
  • Elaioplasts -Elaioplasts helps in storing fats and oils that are needed by the plant.

Inheritance of plastids

There are many plants which are inherited from the plastids from just single parent. Angiosperm inherits plastids from the female gamete while there are many gymnosperms who will inherit plastids from the male pollen. Algae inherit plastids from one parent only. The inheritance of the plastid DNA seems to be 100% uniparental. In hybridisation, the inheritance of plastid seems to be more erratic.

Practise This Question

The plant shown below contains fibrous root.