Evolution of Life, Prokaryotic Species (Bacteria)

• What are stromatolites?

  Fossilized cyanobacteria
• When did the Big Bang occur?

  13.8 billion years ago
• When did Earth form?

  4.5 billion years ago
• When did life appear on Earth?

  3.8 to 3.5 billion years ago
• What are the two domains of early life?

  Bacteria and Archaea
• What does abiogenesis mean?

  Life arising from non-living matter
• Who believed in spontaneous generation of life?

  Aristotle
• What did Francesco Redi disprove?

  Spontaneous generation
• Who coined the term 'cell'?

  Robert Hooke
• What hypothesis gained acceptance in the 19th century?

  Biogenesis
• What is the view on life development presented in the lecture?

  Life is a property of carbon chemistry
• What is the Cell Theory?

  Cells are the basic unit of life
• What are the common features of life according to Cell Theory?

  • Cellular organization
  • Sensitivity to stimuli
  • Growth and metabolism
  • Reproduction
  • Regulation and homeostasis
  • Heredity (genetic information in DNA)
• What is cellular organization?

  Molecules in membranes create an internal environment
• Why do cells need to respond to stimuli?

  To survive in their environment
• What is metabolism?

  Chemical reactions in a cell
• Why must cells reproduce?

  To survive as all cells are finite
• How long do nerve cells last in the cerebral cortex?

  A lifetime
• What is homeostasis?

  Regulation of the internal environment
• What is the role of DNA in heredity?

  Encodes genetic information for life
• What are the stages in the development of life?

  1. Formation of organic compounds
  2. Polymerisation and replication
  3. Enclosure of polymers in membranes
  4. Evolution of the prokaryotic cell
• What was the composition of the primeval atmosphere?

  Nitrogen and carbon dioxide with water vapor
• What did Stanley Miller and Harold Urey's experiments demonstrate?

  Production of organic compounds from inorganic ingredients
• What energy source was postulated for forming complex carbon compounds?

  Electrical discharges in the atmosphere
• What did Miller and Urey simulate in their experiments?

  Lightning strikes in the primeval atmosphere
• What was a flaw in Miller and Urey's experiments?

  Assumed significant methane in the atmosphere
• Where are hydrothermal vents found?

  At mid-ocean ridges where tectonic plates meet
• What do chemosynthetic bacteria use for growth?

  Chemical energy from oxidation reactions
• What is the significance of chondrites in the study of life origins?

  They contain numerous amino acids
• Why are amino acids important?

  They are the building blocks of proteins
• What do cells require for greater control of chemical reactions?

  Membranes to constrain molecules
• What is the "bubble hypothesis"?

  Organic compounds bond on surface-films of bubbles
• What are protobionts?

  Membrane-bounded droplets formed from organic compounds
• What properties did stable protobionts have?

  Self-assemble, split, and form new droplets
• What are ribozymes?

  Enzymes found in ribosomes that link amino acids
• What do ribonucleotides comprise?

  A phosphate group, ribose sugar, and nucleobase
• What can ribonucleotides be converted to?

  ATP for cell signaling and function
• What role do polymers of ribonucleotides play?

  Act as genetic material and enzymes
• What are prokaryotes?

  Unicellular organisms without a nucleus
• What is the Greek meaning of prokaryote?

  Before nucleus