Cell: The Unit of Life

Vocabulary flashcards based on the lecture notes covering cell discovery, history of cell theory, and basic cellular classification.

Cell

The fundamental structural and functional unit of all living organisms; any structure less than a complete cell does not ensure independent living.

Unicellular organisms

Organisms capable of independent existence and performing the essential functions of life, such as Amoeba and Diatoms.

Multicellular organisms

Organisms that consist of more than one cell, for example, plants and animals.

Robert Hooke

The scientist who studied and discovered the cell from a thin slice of cork, though this was a 'dead cell'.

Antonie Von Leeuwenhoek

The first person to observe living cells capable of moving, including bacteria, protozoa, spermatozoa, and red blood corpuscles.

Matthias Schleiden

A German botanist who, in $1838$, observed that all plants are composed of different kinds of cells which form the tissues of the plant.

Theodor Schwann

A German zoologist who, in $1839$, identified the 'Plasma membrane' and concluded that the presence of a cell wall is a unique character of plant cells.

Cell Theory

A theory formulated by Schleiden and Schwann, later modified by Virchow, stating that all living organisms are composed of cells and products of cells, and all cells arise from pre-existing cells.

Rudolf Virchow

The scientist who in $1855$ first explained that cells divided and new cells are formed from pre-existing cells ($Omnis\,cellula-e\,cellula$).

Viruses

An exception to cell theory, these are composed of nucleoprotein particles and are not considered either living or non-living.

Eukaryotic cells

Cells that possess membrane-bound nuclei and other distinct membrane-bound organelles like the Endoplasmic Reticulum (ER) and mitochondria.

Prokaryotic cells

Cells that lack a membrane-bound nucleus and lack membrane-bound organelles.

Cytoplasm

A semi-fluid matrix that occupies the volume of the cell and serves as the main arena of cellular activities in both plant and animal cells.

Organelles

Distinct structures within eukaryotic cells, such as the Golgi complex, lysosomes, mitochondria, microbodies, and vacuoles.

Ribosomes

Non-membrane bound organelles found in all cells, including both eukaryotic and prokaryotic cells.