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20 Cards in this Set

  • Front
  • Back
amino acid
Carbon-chain molecule that is the building block of protein. (p. 476)
Cambrian period
A geological period 0.6 to 0.5 billion years ago during which life on Earth became diverse and complex. Cambrian rocks contain the oldest easily identifiable fossils. (p. 478)
chemical evolution
The chemical process that led to the growth of complex molecules on primitive Earth. This did not involve the reproduction of molecules. (p. 480)
A body within a living cell that contains genetic information responsible for the determination and transmission of hereditary traits. (p. 477)
deoxyribonucleic acid
The long carbon-chain molecule that records information to govern the biological activity of the organism. DNA carries the genetic data passed to offspring. (p. 476)
See deoxyribonucleic acid.
Drake equation
The equation that estimates the total number of communicative civilizations in our galaxy. (p. 490)
Special protein that controls processes in an organism. (p. 476)
A unit of DNA - or sometimes RNA - information responsible for controlling an inherited physiological trait. (p. 477)
life zone
A region around a star within which a planet can have temperatures that permit the existence of liquid water. (p. 486)
Miller experiment
An experiment that reproduced the conditions under which life began on Earth and manufactured amino acids and other organic compounds. (p. 478)
Offspring born with altered DNA. (p. 475)
natural selection
The process by which the best traits are passed on, allowing the most able to survive. (p. 475)
primordial soup
The rich solution of organic molecules in Earth's first oceans. (p. 480)
Complex molecule composed of amino acid units. (p. 476)
ribonucleic acid
Long carbon-chain molecules that use the information stored in DNA to manufacture complex molecules necessary to the organism. (p. 477)
See ribonucleic acid.
The Search for Extra-Terrestrial Intelligence. (p. 489)
A layered fossil formation caused by ancient mats of algae or bacteria, which build up mineral deposits season after season. (p. 481)
water hole
The interval of the radio spectrum between the 21-cm hydrogen radiation and the 18-cm OH radiation. Likely wavelengths to use in the search for extraterrestrial life. (p. 489)