Origins of Life Quiz Review Honors Biology

What Should I Study? Miller & Urey – their experiment, what they concluded Sequencing of origins of life to present day Prokaryotic vs. eukaryotic, anaerobic vs. aerobic, heterotrophic vs autotrophic, unicellular vs multicellular Oxygen was NOT present on early earth, formed later from producers… then formed Ozone layer which serves as a protection from the UV light now. Know how this production of oxygen (due to photosynthetic organisms) changed our world!

Compare & Contrast… Abiogenesis Biogenesis a/k/a Spontaneous Generation the idea that life can arise from nonliving material Examples mice come from haystacks; Flies from rotting meat the idea of life arising from other living organisms Examples Cats make cats; humans make humans;

Several scientists tried to disprove one theory… Who were they Several scientists tried to disprove one theory… Who were they? What were they trying to disprove and how did they do it? Redi & Pasteur Abiogenesis (Spontaneous Generation); Redi-meat/jars/flies ; Pasteur–broth/bacteria/swan neck flasks

Which two scientists created the apparatus seen here? Miller & Urey

Sequence these terms POLYMERS PRIMITIVE CELLS SIMPLE ORGANIC COMPOUNDS (MONOMERS) PROTOCELLS (PRE-CELLS)

Sequence these terms POLYMERS 2 PRIMITIVE CELLS 4 SIMPLE ORGANIC COMPOUNDS (MONOMERS) 1 PROTOCELLS (PRE-CELLS) 3

What theory were Miller and Urey Testing? Theory of chemical evolution (Oparin/Haldane) the organic compounds that made the first living cells arose from chemical reactions occurring on primitive earth…

Miller and Urey tried to recreate the atmosphere of… Primitive Earth

What does letter A represent? Be Specific in your description. Represents oceans – boiling due to the high heat conditions of primitive earth Also created water vapor which leads into the next step

What gases were in the chamber “B”? Ammonia, hydrogen and methane Which gas was notably absent? Oxygen!

What were the results of the Miller Urey Experiment? (Letter E) Amino Acids (simple organic compounds)

List 3 examples of energy sources on Primitive Earth Lightning UV Radiation Geothermal/Heat

Compare & Contrast… Primitive Earth Modern Earth Lacked Free O2 Extermely Hot Brown Oceans Pink Skies No life (originally) Abiogenesis…then biogenesis O2 & Ozone Layer Moderate temperatures Blue Oceans Blue Skies Lots o’ life! Biogenesis only

The earliest cells… Unicellular Prokaryotic Heterotrophic Anaerobic The earliest cells likely had RNA as the genetic material.

Conditions for processes that REQUIRE or USE O2 Aerobic Conditions for processes that DO NOT USE O2 ANAEROBIC

Describe the differences between Prokaryotes and Eukaryotes… LACK a nucleus Unicellular Do not have any membrane-bound organelles Smaller, simpler Contain a nucleus Can be unicellular or multicellular Contain membrane-bound organelles Larger, more complex

Timing is everything Important Dates! Be able to sequence these events (each about a billion years apart from each other)… Important Dates! 10-20 billion years ago – Big Bang 4.5 billion years ago – Origin of Earth 3.8 billion years ago – first cells 100,000-200,000 years ago – modern humans (Homo sapiens) origin of the Earth (~4.5bya) prokaryotic heterotrophs (~3.5bya) prokaryotic autotrophs (first evidence of photosynthesis) (~2.5bya) unicellular (single celled) eukaryotes (~1.5bya) multicellular eukaryotes (~0.5bya)

Endosymbiosis (hypothesis on the origin of mitochondria and chloroplasts) https://highered.mheducation.com/sites/9834092339/student_view0/chapter4/animation_-_endosymbiosis.html

Review the BBB Describe the conditions of the early Earth and the early atmosphere. Differentiate between biogenesis and abiogenesis and justify why biogenesis prevails over abiogenesis on modern earth. Explain how the conditions on early Earth may have led to the formation of organic compounds, pre-cells (protocells) and to the first cells. Analyze Miller and Urey’s experiment in terms of its purpose, design and results. Rationalize the heterotroph hypothesis and the endosymbiotic theory. Infer whether the earliest life on Earth was likely aerobic or anaerobic. Weigh the significance of the evolution of autotrophs in changing the conditions on early earth. Provide evidence for the origin of mitochondria and chloroplasts. Construct an approximate sequence/timing of major points in the evolution of life on earth from the origin of Earth through the emergence of the human species. How did life on Earth begin, and how has it changed over time? What are the 3 domains and 6 kingdoms into which all living organisms are classified? How did prokaryotic cells evolve into eukaryotic cells?