Unit 3: Cell Theory, Types, Structures & Functions
Test Study Guide
Cell Theory and Scientists
There were many different scientists that had an influence in the discovery of cells. The invention and improvement of the microscope
played a key role in the development of our understanding of cells. Below, you will find a list of scientists involved and their contributions to the
scientific community.
1. Robert Hooke- British scientist, who in 1665, built a microscope and looked at cork from a plant. He described the cork as looking like
hundreds of boxes, and named these boxes “cells” which means “little boxes”.
2. Anton van Leeuwenhoek- Dutch merchant, in 1673, built a microscope to look at pond scum. He saw many small creatures swimming
around and named them “animalcules” which means “little animals”. He also was the first person to see bacteria.
3. Matthias Schleiden- German scientist, in 1838, made the observation and conclusion that all plant parts are made of cells. He came to this
conclusion after looking at thousands of plant slides and reading about other scientists’ research.
4. Theodor Schwann- German scientist, in 1839, stated that all animal tissues are made of cells. He concluded this after studying numerous
animals under the microscope. He also wrote the first two parts of the cell theory:
a. ALL ORGANISMS ARE COMPOSED OF ONE OR MORE CELLS.
b. THE CELL IS THE BASIC UNIT OF LIFE IN ALL LIVING THINGS.
5. Rudolf Virchow- German scientist, in 1858, saw that cells could not develop from anything except other cells. He then wrote the third part
of the cell theory:
a. ALL CELLS COME FROM EXISTING CELLS.
CELL THEORY
1. ALL ORGANISMS ARE COMPOSED OF ONE OR MORE CELLS. (Schwann)
2. THE CELL IS THE BASIC UNIT OF LIFE IN ALL LIVING THINGS. (Schwann)
3. ALL CELLS COME FROM CELLS. (Virchow)
Cell Organelles: the structures in cells
Organelle
Cell (plasma) membrane
Nucleus
Ribosomes
Endoplasmic Reticulum
Function
Covers the cell, keeps cytoplasm
Where you enter and exit a city,
in, semi-permeable
the city limits
Control center; stores DNA, largest City hall or the mayor of a city
Picture
*Found in all cells
*Found in most eukaryotic c ells
and most visible organelle
who runs the city
Read genetic material to make
The hard working factory
proteins
workers
*Found in all cells
Makes lipids and other materials, breaks
The transportation system like
*Found in
down hazardous materials, delivery
the roadway/highways
system
Golgi Apparatus
City Equivalent…
Packages proteins for shipment
Packages and ships like the
within the cell and out of the cell
UPS or FEDEX
Eukaryotic Cells
*Found in
Eukaryotic Cells
Lysosomes
Breaks down and disposes of
Trash collector
waste
Mitochondria
Chloroplast
Vacuole
*Found in Eukaryotic Cells
Power plant that provides
cell’s energy, needs oxygen
energy to the homes in the city
Contains chlorophyll, uses sunlight to
Solar powered plants that use
*Found in
make sugar through photosynthesis
sunlight and convert to energy
plant cells
Stores water and other liquids,
Water tower/ food bank
*Found in all
Wall around city
*Found in Plants, algae
plants have large vacuoles
Cell Wall
*Found in all
Makes ATP for cell from sugar, ATP is the
Hard outer-covering, provides strength
and support to cell membrane
Eukaryotic Cells
eukaryotic cells
Fungi, and Bacteria
*Things ALL cells have in common:
-DNA
-cell membrane
-cytoplasm
-ribosomes
Eukaryotic Cells (all organisms except bacteria) have nuclei, have membrane covered organelles, have
linear DNA, and can reproduce sexually and/or asexually
Animal Cell:
Has Centrioles
Small Vacuoles
No Cell Wall
Plant Cell:
Has chloroplasts
Has large vacuole
Has Cell Wall
Prokaryotic Cells (bacteria) have no membrane-covered organelles,
Circular DNA, usually reproduce asexually, and are unicellular