Carbon and water cycle

• How long has life on Earth existed?

  Billions of years
• Why has life on Earth been possible?

  Because it recycles molecules and atoms
• What are some molecules recycled on Earth?

  Water and carbon dioxide
• What happens to atoms over millions of years?

  They can be reused to create organisms
• How many atoms are estimated to be in a human body?

  Six octillion atoms
• Where have the atoms in your body been recycled from?

  Oceans, volcanoes, other animals, and humans
• What are the two cycles covered in the study material?

  • Water cycle
  • Carbon cycle
• What initiates the water cycle?

  Energy from the sun causes evaporation
• What types of water can evaporate in the water cycle?

  Water from lakes, oceans, rivers, and land
• What is transpiration in the water cycle?

  Evaporation of water from plant leaves
• What happens to water vapor in the sky?

  It condenses into clouds
• What is the term for water falling back to Earth?

  Precipitation
• After precipitation, where can water go?

  Into soil, rivers, or be taken up by plants
• What are the main stores of carbon in the carbon cycle?

  • Atmosphere (as carbon dioxide)
  • Plants (in biological molecules)
  • Soil (with microorganisms)
  • Fossil fuels (underground)
  • Animals (in biological molecules)
• What is the primary process in the carbon cycle?

  Photosynthesis
• What do plants and algae convert carbon dioxide into?

  Biological molecules like glucose
• How can carbon return to the atmosphere?

  Through respiration by plants and animals
• What happens to carbon when organisms die?

  It can be decayed or converted into fossil fuels
• What conditions are needed for microorganisms to decay organisms?

  Warm, moist, aerobic conditions
• What do microorganisms release during decay?

  Carbon dioxide during microbial respiration
• What can happen to carbon in anaerobic conditions?

  It can be converted into fossil fuels
• How do humans produce carbon dioxide from fossil fuels?

  By burning fossil fuels
• What is an additional process that releases carbon dioxide?

  Burning plants like logs or biofuels
• What are the key processes in the carbon cycle?

  1. Photosynthesis
  2. Respiration
  3. Decay by microorganisms
  4. Formation of fossil fuels
  5. Burning of fossil fuels
• What is the purpose of the video mentioned in the study material?

  To educate about recycling in ecosystems