Answer: The endosymbiotic hypothesis is that a prokaryotic cell “ate” smaller organelles which evolved into what they are today.…
-Redi, Spallanzani, and Pasteur all used similar experiments to prove that living things are not spontaneously generated and through their experiments they were able to support their hypothesis with scientific reasoning. The experiments preformed were considered valid because of the reproducible outcome in each study.…
Describe at least one of the early research theories about the origins of life on Earth.…
The Primordial Soup Hypothesis, otherwise known as "The Primordial Soup Theory," was developed by the Russian chemist A.I. Oparin and English geneticist J.B.S. Haldane. Oparin & Haldane(1920) formed this idea separately though. In this theory, the basic aspects of life all came from simple molecules that formed in the atmosphere with the addition of oxygen. They believed that Earth had a chemically reducing atmosphere. This produced monomers. These monomers formed a "soup," that developed organic polymers, and the basic building blocks of life, in the oceans or ponds. Neither scientist had any real evidence to support their theory until Stanley Miller & Harold Urey(1953) decided to test their theory. They used a highly reduced mixture of gases- methane, ammonia and hydrogen- to form organic monomers like amino acids. This experiment gave support to the idea Oparin and Haldane had about the atmosphere being exposed to energy producing monomers. They both believed that organic molecules could have spontaneously formed from…
The theory that life began in the distant past from nonliving molecules that became able to reproduce themselves is called:…
* The slow accumulation of these molecules in the early oceans over a long period of time formed the prebiotic soup.…
1. The Cell Theory: Robert Hooke observed cells. All organisms are composed of cells that have DNA.…
1. The four stages of hypothesis for the origin of life on Earth by chemical evolution is…
BSC2011C Final Review Unit 1 Review Ch. 25, 22, 23, 24, 26, 19, 27 Ch. 25 1. Life is metabolism and heredity. Metabolism is the mechanism that creates order and complexity from chaos, by acquiring and expending energy. Heredity is the ability of an organism to copy itself and it is broken down into: i. Multiplication, ii. Inheritance, iii. Variation. 2. DNA codes via RNA for 20 of naturally occurring amino acids. Amino Acids are the building blocks of proteins and bodies. DNA stores and transmits hereditary information, but proteins do most of the work. DNA IS THE UNIVERSAL DIGITAL CODE FOR LIFE. To replicate and synthesize proteins, DNA relies on the pre-existence of protein molecules and RNA molecules. 3. RNA is the bridge between DNA and proteins, via mRNA for transcription and rRNA for translation. Thus, RNA can survive on its own while DNA relies on the existence of RNA and proteins, with them DNA is helpless. 4. The 4 points of “first life” are: 1. The Abiotic (non-living) synthesis of small organic molecules, such as amino acids and nucleotides. 2. The joining of these small molecules into macromolecules, including proteins and nucleic acids. 3. The packing of these molecules into “protobionts,” droplets with membranes hat maintained an internal chemistry different from that of their surroundings. 4. The origin of self-replicating molecules that eventually made inheritance possible. 5. The first cells to develop occurred in this order: Monomers > Polymers > Protobionts > RNA ‘world’ > DNA protobionts > first cell. 6. Fossils are the evidence of life and evolution. Organisms trapped in sediment > remain mineralized with hard and soft parts. 7. Fossils can be dated by two methods: Radiometric dating & Magnetism. In Radiometric dating, the age is based on the decay of radioactive isotopes. A radioactive “parent” isotope decays to a “daughter” isotope at a constant rate. The rate of decay is expressed by the half-life, the time requires for 50% of the parent…
This theory states that everything existed as a speck or “seed” of themselves. The seeds came from all over the universe and traveled through space from one location to another. Some people believe this is how life on Earth began. There are three variations of this hypothesis. They are Interstellar (flying rocks from other planets spread the seed material from one solar system to another), interplanetary (Seeds are spread one planet to another in the same solar system, and Directed panspermia (spreading of seeds from extraterrestrials to Earth). Recent Indian and British researchers were able to get samples from the stratosphere that contained living cells. Another example to support this theory is another scientist found extraterrestrial bacteria inside a meteorite that scientists think is over four-billion years old. Anaxagoras reasoning behind his theory is that he wondered why flesh isn’t made out of flesh and where did we come from? So he answers himself saying a being from another world made us and put us here. Different scientists have tested this panspermia hypothesis by sending microbes into space and seeing if they can stand reentry into earth’s…
They found that the methane had converted to simpler carbon compounds, including H2 cyanide, which combined into more complex molecules with carbon bonds, including the amino acids, which are building blocks of proteins. This experiment is significant because it shows that the key molecules of life could have formed the atmosphere in early earth. (Yahoo answers)…
Thesis: social and cultural diff b/w human groups are expressions of fundamentally diff biological stocks (races)…
The Cambrian explosion is named for the geologically sudden appearance of numerous metazoan body plans some 540 million years ago (James W. Valentine et al. 1999). In Earth’s pre-history during the Cambrian period many animal phyla suddenly appear in fossil records and introduced more complex organisms. “For that the evolution of the planet Earth is described by the co-evolution of the geosphere biosphere system” (Werner Von Bloh et al. 2003). A sudden increase of biomass and rapid cooling had occurred without much explanation but that caused the widespread of the introduction of more complex organisms and multicellular life. A compilation of the patterns of fossil and molecular diversification, comparative developmental data, and information…
“Every time we ask a question, we’re generating a possible version of life.” (Epston, D.,1995, Cowley & Springen, p. 74, as cited in Freedman, J. & Combs, G., 1996, p. 113)…
Chapter 1 Humans and the Microbial World A Glimpse of History Science of microbiology born in 1674 Antony van Leeuwenhoek (1632–1723) • Made simple magnifying glass • Studied lake water • Observed ‘animalcules’ Robert Hooke • Also credited with discovery • Described ‘microscopical mushroom’ (common bread mold) in 1665 1 Importance of Microorganisms…