Send the link below via email or IMCopy
Present to your audienceStart remote presentation
- Invited audience members will follow you as you navigate and present
- People invited to a presentation do not need a Prezi account
- This link expires 10 minutes after you close the presentation
- A maximum of 30 users can follow your presentation
- Learn more about this feature in our knowledge base article
AP Biology: The Origin of Life
Transcript of AP Biology: The Origin of Life
Enduring understanding 1.D: The origin of living systems is explained by natural processes
Essential knowledge 1.D.1: There are several hypotheses about the natural origin of life on Earth, each with supporting scientific evidence.
Essential knowledge 1.D.2: Scientific evidence from many different disciplines supports the models of the origin of life.
The Origin of Life
Basic Theory on the Origin of Life
Four Main Stages
1. Small organic molecules were synthesized from inorganic compounds (amino acids, nucleotides, etc.)
2. Macromolecules were formed from the joining of these small molecules.
3. Droplets containing a membrane with an internal chemistry that was different from the external called protobionts, were packed with these molecules.
4. Inheritance was made possible from the emergence of self-replicating molecules.
Oparin and Haldane
Characterized early Earth’s atmosphere to be compacted with water vapor, carbon dioxide, methane, ammonia, nitrogen, hydrogen and hydrogen sulfide.
The atmosphere of primitive earth combined with lighting and UV radiation is thought to have formed organic compounds.
- The early Earth atmosphere was chemically reducing.
- The exposure of energy to the inorganic compounds within the atmosphere
How Scientists Can Determine the History of Life
Fossil record: the sequence in which fossils appear in the layers of sedimentary rocks
- incomplete considering that this method favors those who existed in abundance and for a long period of time and had hard bones or shells.
Relative dating - using the layers of the fossil record to determine when organisms were fossilized
- half life - the time it takes for a substance to reduce by half.
Hillis, David M.. Principles of life. Sunderland, MA:
Sinauer Associates ;, 2012. Print.
Holtzclaw, Fred W., Theresa Knapp Holtzclaw, Neil A.
Campbell, and Jane B. Reece. AP* biology: to
accompany Biology, Campbell, Reece, 8e AP* edition. San Francisco:
Pearson Benjamin Cummings, 2008. Print.
Earth was formed approximately 4.6 billion years ago, 3.8 billion years ago life was formed
The earliest of organisms were mostly unicellular and microscopic.
All organisms came from the same origin.
Origin of Life Theory
1. Primitive Earth provided inorganic precursors from which organic molecules could have been synthesized due to the presence of available free energy and the absence of a significant quantity of oxygen.
2. In turn, these molecules served as monomers or building blocks for the formation of more complex molecules, including amino acids and nucleotides.
3. The joining of these monomers produced polymers with the ability to replicate, store and transfer information.
4. These complex reaction sets could have occurred in solution (organic soup model) or as reactions on solid reactive surfaces.
5. The RNA World hypothesis proposes that RNA could have been the earliest genetic material.