Amyloplast

Colourless, double-membrane-bound plastid found in plant cells. Contains starch granules, where starch is synthesised and stored. Contains its own DNA and ribosomes, as it belongs to the plastid family. Lacks the chlorophyll-containing thylakoid system required for photosynthesis.

Synthesises and stores starch from sugars produced during photosynthesis. Stored starch can be hydrolysed into sugars when needed for respiration, growth and other metabolic processes. In specialised root cells, amyloplasts can act as statoliths that settle under gravity, contributing to gravitropism.

Plant cells, particularly starch-storing tissues such as potato tubers, roots and seeds. Absent in animal and prokaryotic cells.

Provides long-term storage of carbohydrates as insoluble starch, which has little effect on the cell's osmotic balance. Stored starch serves as an energy and carbon reserve for growth and metabolism. In specialised cells, amyloplasts help plants detect gravity and regulate the direction of growth.

Insoluble starch granules store carbohydrate compactly with little osmotic effect; dense starch filled amyloplasts settle in gravity sensing cells to help indicate the direction of gravity.