Cytology - the study of cells

Mr. FemiaBiology

Important scientists – Robert Hooke

• 1665 - Named cells after the small boxy rooms that monks live in

Robert Hooke

• He first saw and named "cells" while he was experimenting with a new instrument we now call a "microscope."

• Used cork slices • He saw tiny box-like

shapes.

Anton van Leeuwenhoek

• 1670 - First scientist to observe living cells

• Father of microscopy

Anton van Leeuwenhoek

• Saw life in pond water

• First to observe• Sperm• Red blood cells• Gunk from teeth

Leeuwenhoek's microscope was very rudimentary

Matthias Schleiden

• 1830 – German Botanist• All plants are made of

cells"One who wishes to be a

botanist or zoologist without a microscope, is at least as great a fool as one who wants to observe the heavens without a telescope”

Thomas Schwann

• 1830 - German• Worked with Schleiden• Discovered all animals

are made of cells

“The Cell Theory”

• 1. All organisms are composed of one or more cells

• 2. The cell is the basic unit of organisms

• 3. All cells come from preexisting cells

Cytology – the study of cells

Three basic parts of a cell

• 1 cytoplasm• 2 nucleus• 3 cell membrane

Two Kinds of Cells 1. Prokaryotic Cells

• Small• Simple • No nucleus• Bacteria

Eukaryotic cells - all other cellsThese include

• protists• fungi• plants• animals

• Have a nucleus

• Cells contain structures called organelles.

Prokaryotic vs. Eukaryotic

Plasma membrane

• All cells are surrounded by a plasma membrane.

• It separates the contents of the cell from its environment.

• It regulates the passage of molecules into and out of the cell.

Microvilli

• Cells that are specialized for absorption (ex: intestinal cells) have folds in the plasma membrane called microvilli that increase the surface area.

Pseudopodia are temporary extensions of the plasma membrane used for movement or to engulf particles. Pseudopodia can be seen in the Amoeba below.

Cell Wall

• The cell wall functions to support and protect the cell.

• Plants have cell walls composed of cellulose; fungi have walls composed of chitin.

Nucleus The nuclei can be seen in the photograph of human cheek cells • The largest organelle

Cytoplasm – the material enclosed by the plasma membrane, excluding the nucleus

Cilia and Flagella

• Hair-like structures projecting from the cell that function to move the cell by their movements. They contain cytoplasm and are enclosed by the plasma membrane.

Cells the basic unit of living organisms• Observe and draw

• Prokaryotic & Eukaryotic• Label

• Nucleus• Cell membrane• Cytoplasm