20 CELL BIOLOGY CONCEPTS

PRERNA FOR IAS

20 CELL BIOLOGY CONCEPTS

1. Cell Theory

Cell Theory is one of the fundamental principles of biology. It states that all living organisms are composed of one or more cells, the cell is the basic structural and functional unit of life, and all cells arise from pre-existing cells. Proposed by Matthias Schleiden and Theodor Schwann and later expanded by Rudolf Virchow, this theory revolutionized biological science. Cells perform all essential life processes, including metabolism, growth, and reproduction. Whether an organism is unicellular like bacteria or multicellular like humans, cells are the building blocks of life. Cell Theory forms the foundation of modern biological understanding.

2. Prokaryotic Cell

Prokaryotic cells are simple, primitive cells that lack a true nucleus and membrane-bound organelles. Their genetic material is present in a nucleoid region instead of a nucleus. Bacteria and archaea are examples of prokaryotic organisms. These cells are usually smaller and structurally simpler than eukaryotic cells. Despite their simplicity, prokaryotes carry out all essential life processes such as metabolism, growth, and reproduction. They often possess structures like cell walls, ribosomes, flagella, and plasmids. Prokaryotic cells reproduce mainly through binary fission and play important ro