HOW DID LIFE BEGIN?
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HOW DID LIFE BEGIN?
The Earth, a planet full of life. All living-beings are basically made up of the same chemical elements. The principal characteristics of living organisms is their being able to reproduce themselves. DNA. The beginning of the Earth’s formation, some 4,500 million years ago. The theories of Alexander Oparin and Miller. The first organisms and their evolution through time. Summary.
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INTRODUCTION
-Charles Darwin’s study of the varied froms of life found in the Galapagos Islands greatly influenced his thinking. He concluded that life could have begun as a process of evolution.
-All living-beings are basically made-up of the same chemical elements.
WHAT IS LIFE?
-All living creatures have a certain number of essential characteristics which are not shared with mineral matter.
-The main characteristic of all living-beings is their capacity to reproduce themselves. Furthermore, they can adapt themselves to their surroundings.
-The genetic matter orders the manufacture of proteins, which are indispensable for carrying out all living functions.
-DNA is a nucleic acid capable of duplicating itself in order to leave exact copies of itself to each of its descendants. All DNA molecules of all living-beings function exactly the same way.
HOW LIFE BEGAN
-The Earth was formed some 4,500 millions years ago, together with the other planets making up our Solar system.
-Alexander Oparin and his theory of life.
-Stanley Miller, assisted by Harold Urey, reproduced in a laboratory, the primitive atmosphere.
-Proteins and nucleic acids formed the first living units
THE FIRST ORGANISMS
-The first living organisms fed upon substances found in the Earth’s primitive oceans.
-The photosysthesis
-The first plants
SUMMARY |
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