Differences between Mitochondria and Plastids:
Mitochondria and plastids are two types of organelles found in eukaryotic cells, each with distinct functions and characteristics. Here are the key differences between the two:

Structure:
- Mitochondria are rod-shaped organelles with a double membrane structure. They have an outer membrane and an inner membrane with folds called cristae.
- Plastids, on the other hand, have a double membrane structure as well. They contain their own DNA and ribosomes, similar to mitochondria.

Function:
- Mitochondria are known as the "powerhouses" of the cell because they are responsible for producing energy in the form of ATP through cellular respiration.
- Plastids are involved in processes such as photosynthesis, storage of starch, and synthesis of pigments like chlorophyll.

Types:
- Mitochondria are present in almost all types of eukaryotic cells and are essential for cellular respiration.
- Plastids are found only in plant cells and some protists. They include chloroplasts (responsible for photosynthesis), chromoplasts (store pigments), and amyloplasts (store starch).

Pigments:
- Mitochondria do not contain pigments and are not involved in photosynthesis.
- Plastids, particularly chloroplasts, contain chlorophyll, a green pigment that is essential for capturing light energy during photosynthesis.

Endosymbiotic Theory:
- Mitochondria are believed to have evolved from ancient aerobic bacteria that were engulfed by a primitive eukaryotic cell.
- Plastids are thought to have evolved from ancient photosynthetic bacteria that were also engulfed by a eukaryotic cell.
In conclusion, while both mitochondria and plastids are important organelles in eukaryotic cells, they have distinct structures, functions, and evolutionary origins that set them apart from each other.