Download PAGE 21 All living things are composed of cells. Some organisms

***CELLS (CELL THEORY)***
PAGE 21
All living things are composed of cells. Some organisms only contain one cell, while others have billions of
cells. The processes essential for the survival of organisms are performed by the cells.
THE CELL THEORY
1. All living things are made up of one or more cells.
2. Cells are the basic units of structure and function in organisms.
3. All cells come from preexisting cells.
WHO FIGURED OUT THE CELL THEORY AND HOW DID THEY DO IT?
During the last four centuries, improvements in the microscope and the development of other techniques
have made it possible for biologists to observe and study cells. The cell theory was developed from the
work of a number of scientists.
Anton van Leeuwenhoek (1632-1723) made powerful simple microscopes that he used to study samples
of living material. Van Leeuwenhoek was the first to see sperm cells, bacteria, and protozoa.
Robert Hooke (1635 – 1703) made compound microscopes that he used to observe thin slices of cork. He
used the term “cells” for the small compartments that make up cork.
Robert Brown, in 1831, concluded from his studies that all plant cells contain a nucleus.
Matthias Schleiden, in 1838, concluded that all plants are made up of cells.
Theodor Schwann, in 1839, concluded that all animals are made up of cells.
Rudolph Virchow, in 1855, concluded that all cells arise only from preexisting cells.
DRAW A CARTOON STRIP BELOW SHOWING ONE PART OF THE CELL THEORY
***CELLS (TYPES – NUMBER - EUKARYOTE VERSUS PROKARYOTE)***
Cells are the basic units of ________________________.
Cells can only be observed under a ______________________________.
Basic Types of Cells
Animal cell
Plant cell
Bacteria cell
Number of Cells
Unicellular - ________________________________________________________
Multicellular - _______________________________________________________
Cells May Be Prokaryotic or Eukaryotic
_________________ = include ______________ & lack a _______________ or membranebound structures called ___________________.
_________________ = include most other cells & have a _______________ and membrane-bound
organelles. (____________, ____________, & _______________)
Prokaryotes
Nucleoid region contains ______________
Cell ____________ & cell _________
Contain _______________ (no membrane) to make proteins in their ______________
Eukaryotes
Contain 3 basic cell structures:
1. __________________
2. __________________
3. ____________________________________________________
Two main types of eukaryotic cells = 1. ____________ CELL 2. _________________CELL