Cell Theory – Flashcards

A set of Q&A flashcards covering the cell theory, its history, classic and modern postulates, key contributors, and related concepts.

What is the basic unit of life?

The cell.

Who first discovered cells and in what year?

Robert Hooke in 1665 (observed cells in cork with a compound microscope).

In what year was the cell theory formally established and which scientists were key contributors?

1839; Theodor Schwann and Matthias Schleiden (with Rudolf Virchow contributing the third postulate).

What are the classic postulates of the original cell theory?

All living things are made of cells; cells are the basic unit of life; cells arise from pre-existing cells.

Who revised the third postulate of the classic cell theory?

Rudolf Virchow.

What are the main additions of the Modern Cell Theory beyond the original postulates?

Cells contain hereditary information (DNA); energy flow (metabolism) occurs in cells; all cells have similar chemical composition within organisms of similar species; cells come from pre-existing cells.

What did Schleiden and Schwann conclude about plant and animal tissues?

They showed that cells are present in both plant and animal tissues, leading to the idea that all living things are made of cells.

Approximately how many cells are in the adult human body?

About 37.2 trillion cells.

Where do metabolic processes occur in living organisms?

In the cells—the basic unit of life.

If something performs life functions but isn't made of cells, is it alive according to cell theory?

No. Life processes occur in cells, and all living things are made of cells.

Name one early contributor to the cell theory.

Robert Hooke.

Which two scientists are credited with formulating the cell theory in the 19th century?

Theodor Schwann and Matthias Schleiden.

What discovery did Schleiden and Schwann make about tissue composition?

Cells are present in both plant and animal tissues; all living things are made of cells.

What does the phrase 'the cell is the basic unit of life' mean?

All metabolic and life-sustaining activities occur at the cellular level.

Why is the discovery of cells important to biology?

It established the cell theory as a foundational principle, explaining that organisms are composed of cells and that cells are the basic unit of life.

What are the two basic types of cells mentioned?

Prokaryotic and Eukaryotic cells.