Essential Idea:  There is an unbroken chain of life from the first cells on Earth to all cells in organisms alive today.

• Outline answer to each objective statement for topic 1.5
• Quizlet study set for this topic

At SHS, Topic 1.5 is taught in the following class unit(s):

• Concepts of Biology
• Prokaryotic Cells
• Eukaryotic Cells

1.5.U1  Cells can only be formed by division of preexisting cells.

• Discuss implications of all cells being formed from preexisting cells.​​

1.5.U2  The first cells must have arisen from non-living material.

• Outline the four processes needed for the spontaneous origin of cells on Earth.
• Outline the experiments of Miller and Urey into the origin of organic compounds.
• Define polymerization, monomer and polymer.
• Outline two properties of RNA that would have allowed it to play a role in the origin of life.
• ​Outline why fatty acids were likely the primary component of the membrane of early cells.

1.5.U3  The origin of eukaryotic cells can be explained by the endosymbiotic theory.

• State the endosymbiosis theory.
• Outline the major events in the origin of eukaryotic cells.
• Describe the evidence for the endosymbiotic theory.​

1.5.A1  Evidence from Pastuer’s experiments that spontaneous generation of cells and organisms does not now occur on Earth.

• Define spontaneous generation.
• Describe Pasteur’s experiments about spontaneous generation.
• ​Explain why Pasteur’s experiments did not support the idea of spontaneous generation. ​

1.5.NOS  Testing the general principles that underline the natural world- the principles that cells only come from pre-existing cells needs to be verified.​

• Outline historical thinking about spontaneous generation.
• Summarize the Redi experiment.
• Summarize the Spallanzani experiment.
• List reasons why biologists now universally accept that cells only come from preexisting cells.