Cell Theory and Early Microscopy

24 question-and-answer flashcards reviewing key people, discoveries, and principles related to the development of cell theory and early microscopy.

What is the fundamental unit of life called?

The cell

List the five traditional biological levels of organization from smallest to largest.

Cells → Tissues → Organs → Organ Systems → Organism

Which Dutch lens-maker invented the first compound microscope (~1590)?

Zacharias Janssen

The word “lens” is derived from the Latin word for what object?

Lentil (lens) because a double-convex lens resembles its shape

Who first used the term “cell,” and in what material did he observe them?

Robert Hooke; thin slice of cork

In what year did Robert Hooke publish his observations in ‘Micrographia’?

1665

From what Latin words does “cell” originate, and what do they mean?

Cella / Cellulae; meaning “small room” or “honeycomb cell”

Who is known as the ‘Father of Microscopy and Microbiology’?

Anton (Antoine) van Leeuwenhoek

Approximately how much magnification did van Leeuwenhoek’s best lenses achieve?

About 270× (almost 300-fold)

What moving microscopic organisms did van Leeuwenhoek call “animalcules”?

Protozoa, bacteria, and other unicellular organisms

Which types of human cells did van Leeuwenhoek first observe?

Red blood cells and sperm cells

What botanical scientist concluded that plants are composed of cells?

Matthias Jakob Schleiden

Which physiologist determined that animals are also composed of cells?

Theodor Schwann

Who first described the cell nucleus in plant cells (1831)?

Robert Brown

Which scientist proposed that “all cells arise from pre-existing cells”?

Rudolf Virchow

State Virchow’s famous Latin phrase summarizing his idea about cell origin.

“Omnis cellula e cellula”

Classical Cell Theory Tenet #1

All living organisms are composed of one or more cells.

Classical Cell Theory Tenet #2

The cell is the basic unit of structure and function in organisms.

Classical Cell Theory Tenet #3

Cells arise only from pre-existing cells.

Modern Cell Theory Addition #4

Cells carry genetic material that is passed to daughter cells during division.

Modern Cell Theory Addition #5

All cells share essentially the same basic structure and chemical composition.

Modern Cell Theory Addition #6

Energy flow (biochemical processes) occurs within cells.

Which scientific debate motivated further microscope investigation into cells?

The debate over spontaneous generation

Why are cells considered the “building blocks of life”?

Because they are the simplest living units and the basis of biological organization