Ecology

• What is the purpose of using quadrats in ecology?


  To estimate the population size of an organism in different areas
• How do you calculate the mean number of organisms per quadrat?


  Mean = total number of organisms / number of quadrats
• What steps are involved in using quadrats to find the distribution of organisms?


  1. Mark out a line in the study area.
  2. Collect data along the line using quadrats.
  3. Count the organisms.
  4. Repeat the process and find the mean.
  5. Plot graphs to analyze correlations with abiotic factors.
• What does a pyramid of numbers represent?


  It shows the number of organisms at each trophic level in a food chain
• What does a pyramid of biomass represent?


  It shows the mass of living material at each trophic level
• What does a pyramid of energy transfer illustrate?


  It shows the energy transferred to each trophic level in a food chain
• What is the primary source of energy for nearly all life on Earth?


  The energy from the sun
• Why is not all energy passed down through the food chain?

  Because 90% of energy is lost at each trophic level
• If 1000 g of plants are consumed, how much energy is typically passed to the next trophic level?


  100 g of energy is passed, as 10% is transferred
• What are the main steps of the water cycle?

  1. Sun heats water, causing evaporation.
  2. Water vapor cools and falls as precipitation.
  3. Plants release water vapor through transpiration.
  4. Water condenses into droplets forming clouds.
  5. Heavy droplets fall as rain, snow, sleet, or hail.
• What are the key processes in the carbon cycle?


  • Plants use CO2 for photosynthesis.
  • Animals consume carbon compounds from plants.
  • Respiration releases CO2 back into the atmosphere.
  • Decomposition breaks down organic matter, releasing CO2.
  • Combustion of fossil fuels releases CO2.
• What is the role of microorganisms in decomposition?


  They break down dead plants and animals, releasing nutrients and CO2
• What is produced when fossil fuels are burned with insufficient oxygen?

  Carbon monoxide
• How does carbon monoxide affect red blood cells?


  It prevents red blood cells from transporting oxygen
• What are the consequences of deforestation on the environment?


  • Reduces nutrient retention in soil.
  • Increases soil erosion.
  • Alters local climate.
  • Disrupts water cycles.
  • Leads to loss of biodiversity.
• What is the impact of acid rain on ecosystems?


  • Lowers pH of soil and water bodies.
  • Harms aquatic life and plant growth.
  • Can kill trees and other organisms.
• Nitrogen Fixation


  Conversion of atmospheric N2 into a form usable by organisms, e.g., ammonia (NH3) or nitrate (NO3-)
• Ammonification


  Decomposition of organic matter, releasing ammonia (NH3)
• Nitrification


  Conversion of ammonia (NH3) into nitrite (NO2-) and then nitrate (NO3-) by bacteria
• Denitrification


  Conversion of nitrate (NO3-) back into nitrogen gas (N2) by bacteria
• Assimilation


  The process of plants and some microorganisms using nitrate (NO3-) or amino acids to build molecules such as proteins, nucleic acids, and amino sugars
• Lightning Nitrogen Fixation


  Process by which lightning fixes atmospheric nitrogen (N2) into more reactive species, such as nitric oxide (NO) and nitrous oxide (N2O), which can be used by plants.
• examples of greenhouse gases


  water vapour, carbon dioxide, nitrous oxide, methane, CFCs(chlorofluorocarbons)
• Habitat


  a place where and organism lives
• ecosystem


  all the organisms living in a particular area and all non living conditions
• Food webs


  a more complex version of a food web
• primary consumer


  eaten by secondary consumer
• primary consumer


  eaten by secondary consumer eaten by secondary consumer
• producer


  makes own food using energy from sun e.g plants
• population


  all the organisms of one species in a habitat
• secondary consumers


  eaten by tertiary consumers
• community


  all the different species in a habitat
• decomposers in nitrogen cycle


  break down proteins and urea and turn them into ammonia this forms ammonia ions in soil
• food chains


  describes how energy and nutrients move through an ecosystem