The Cell

Copyright Pearson Prentice Hall Early Microscopes In 1665, Robert Hooke used an early compound microscope to look at a thin slice of cork, a plant material. Cork looked like thousands of tiny, empty chambers. Hooke called these chambers “cells.”

Copyright Pearson Prentice Hall The Cell Theory In 1838, Matthias Schleiden concluded that all plants were made of cells. In 1839, Theodor Schwann stated that all animals were made of cells. In 1855, Rudolph Virchow concluded that new cells were created only from division of existing cells. These discoveries led to the cell theory.

 Consist of 3 major parts ◦ 1. All living things are made of cells ◦ 2. Cells are the basic unit of structure and function ◦ 3. All cells come from pre-existing cells

 Is the basic unit of structure and function  Is the basic living structure of life  Hooke and Leewenhoek individually helped to identify and comprehend the existence of the cell. Their work opened doors for others.  R. Virchow  M. Schleiden  T. Schwann

 Even though there are various types of cells, all have characteristics that demonstrate evolutionary development.  1. Cell membrane(plasma) ◦ serves as a barrier of protection ◦ Serves to support the cell ◦ Regulates what enters and leaves the cell  2.Cytoplasm –jelly like substance that is encased within the walls of the cell membrane. In more advanced cells it houses organelles  3. Hereditary Information- at some point all cells contain either DNA or RNA  4. Ribosomes-synthesize or make proteins

 Cells fall into 2 broad groups which are easily distinguishable.  Prokaryote  Eukaryote

 Common Characteristic include: ◦ They are single celled organisms ◦ They DO NOT have a nucleus ◦ Genetic information in found in the cytoplasm ◦ They DO NOT contain membrane organelles (mitochondria, vacuoles, etc.) ◦ Usually referred to as BACTERIA ◦ Oldest of the cell types ◦ Most can live in extreme conditions and habitats

 Common characteristics include: ◦ They have the ability to become multicellular ◦ They HAVE a defined nucleus: (houses DNA) ◦ They HAVE membrane bound organelles that have specialized functions ◦ Most commonly subdivided into plant and animal cell but also includes some protist and fungi.

Copyright Pearson Prentice Hall The cell theory states that new cells are produced from  nonliving material.  existing cells.  cytoplasm.  animals.

Copyright Pearson Prentice Hall One way prokaryotes differ from eukaryotes is that they  contain DNA, which carries biological information.  have a surrounding barrier called a cell membrane.  do not have a membrane separating DNA from the rest of the cell.  are usually larger and more complex.

 Students will create a booklet about cells that should include the following information: ◦ Create a cover sheet that includes  Title ( Cytology Booklet)  Name  Date  Class Period ◦ Page 1 should include a labeled and colored diagram of a BACTERIA (Prokaryotic) CELL ◦ Page 2 should include a labeled and colored diagram of an ANIMAL CELL ◦ Page 3 should include a labeled and colored diagram of a PLANT CELL ◦ Page 4 should include a chart of organelles with their functions ◦ Worksheet pp (issued by teacher) ◦ An article critique about cells (article of your choice)

Cell PartFunction Plant/Animal/Prokaryote Ex: nucleus Controls all cell functions Found in plant, animal cells only