Prokaryotic cells are characterized by the absence of a defined nucleus and are typically smaller than eukaryotic cells. Examples include bacteria and archaea.

Eukaryotic cells have a well-defined nucleus surrounded by a nuclear membrane. They are found in animals, plants, fungi, and protists.

The nucleus is the organelle that contains DNA, the genetic material of the cell. It regulates cellular activities by controlling gene expression.

Ribosomes are the sites of protein synthesis in the cell. They can be free in the cytoplasm or attached to the rough endoplasmic reticulum.

The endoplasmic reticulum (ER) has two forms: the rough, which is covered with ribosomes and involved in protein synthesis, and the smooth, which participates in lipid synthesis and carbohydrate metabolism.

The Golgi apparatus is the organelle responsible for the modification, packaging, and distribution of proteins and lipids for exocytosis or delivery to other organelles.

Mitochondria are known as the powerhouses of the cell. They are responsible for the production of ATP through the process of cellular respiration.

Chloroplasts are present in plant cells and some protists. They are the site of photosynthesis, where light energy is converted into chemical energy in the form of glucose.

Lysosomes contain digestive enzymes that break down complex molecules such as proteins, lipids, and carbohydrates, as well as old, damaged organelles.