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Bio 105 Chapter 18 Quiz

Terms in this set (15)

Stages of the Origin of Life
Stage 1. Organic monomers; Stage 2. Organic polymers; Stage 3. Protocells; Stage 4. Living cells
Stage 1. Organic monomers
Simple organic molecules, called monomers, evolved from inorganic compounds before the existence of the first cells. Amino acids, the basis of proteins, and nucleotides, the building blocks of DNA and RNA, are examples of organic monomers.
Stage 2. Organic polymers
Organic monomers were joined, or polymerized, to form organic polymers, such as DNA, RNA, and proteins.
Stage 3. Protocells
Organic polymers became enclosed in a membrane to form precursors to the first cells, called protocells or protobionts
Stage 4. Living cells
Protobionts acquired the ability to self-replicate, as well as other cellular properties
The Primordial Soup Hypothesis
...
Iron-sulfur world hypothesis
Dissolved gases such as carbon monoxide, ammonia, and hydrogen sulfide rise from thermal vents and pass over iron and nickel. The resulting sulfides act as catalysts to drive the evolution of organic molecules from inorganic molecules.
Extraterrestrial Origins Hypothesis
Meteorites carrying organic molecules seeded the Earth with organic molecules.
The Protein-First Hypothesis
Amino acids present in shallow puddles along ocean shores are heated by the sun to form proteinoids with catalytic properties.
The RNA-First Hypothesis
Organic monomers evolve into RNA, which functions as a catalyst to direct the formation of other molecules.
The remains and traces that provide evidence of past life are called
fossils
Typically when an organism dies, their body becomes _________. However, sometimes the organism is buried quickly or in a manner so that this process does not occur, and instead, the organism becomes ____________ .
decomposed, fossilized
Often, the shell, bones, and ____________ of organisms undergo this process.
teeth
The study of these ____________ and the information that they can provide is called ____________ .
fossils, paleontology
Most of these ____________ are found in ____________ rock, formed by the gradual settling of ____________ into layers called ____________ .
fossils, sedimentary, sediment, stratum
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