Plastid

Definition

Plastids are double-membrane organelles found in the cells of plants and algae. They are involved in the synthesis and storage of food and can differentiate into various types based on function, such as chloroplasts for photosynthesis.

5 Must Know Facts For Your Next Test

1. Plastids contain their own DNA, which is similar to bacterial DNA, supporting the endosymbiotic theory.
2. Chloroplasts, a type of plastid, are essential for photosynthesis in plants and algae.
3. Plastids can differentiate into several forms including chloroplasts, chromoplasts (which synthesize pigments), and leucoplasts (involved in the storage of starches).
4. The development of plastids involves both nuclear-encoded and plastid-encoded genes.
5. Plastid division is independent but often coordinated with cell division.

Review Questions

• What is the primary function of chloroplasts?
• How does the presence of their own DNA support the endosymbiotic theory for plastids?
• Name two other types of plastids besides chloroplasts and their functions.

Related terms

Chloroplast: A type of plastid that contains chlorophyll and is responsible for photosynthesis.

Endosymbiotic Theory: A theory that explains how eukaryotic cells may have evolved from prokaryotic cells through a symbiotic relationship.

Leucoplast: A type of colorless plastid involved in the storage of starches, oils, or proteins.