7 questions on "The Microbial World - Microorganisms and the Biosphere"

Give a summary about life on earth through the ages.
The earth is 4.6 billion years old. The first cells appeared between 3.8 and 3.9 billion years ago. The atmosphere was anoxic until about 2 billion years ago. Metabolisms were exclusively anaerobic until evolution of oxygen-producing phototrophs, this happened because of the cyanobacteria. Life was exclusively microbial until about 1 billion years ago.
How are the three domains of life connected to each other?
From the last universal common ancestor (LUCA), evolution proceeded to form two domains:
  • Bacteria
  • Archaea

Archaea later diverged to form two domains:
  • Archaea
  • Eukarya
Wat is microbial ecology ?
Hoe micro-organismes ecosystemen beïnvloeden
How are diversity and abundance controlled?
Diversity and abundances of microbes are controlled by resources (nutrients) and environmental conditions (e.g., temp, pH, O2).
How do microbes interact with their physical and chemical environment?
Ecosystems are greatly influenced (if not controlled) by microbial activities. Microorganisms change the chemical and physical properties of their habitats through their activities. For example, removal of nutrients from the environment and the excretion of waste products
How old is earth and when did cells first appear on earth?
The earth is 4.6 billion years old. Cells first appeared between 3.8 and 3.9 billion years ago.
Why were cyanobacteria so important in the evolution of life on earth?
Cyanobacteria were the first bacteria that produced O2.
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