biology topic 9 - ecosystems + material cycles

• What is an individual part of a species called?

  Individual
• How do populations interact in a habitat?

  They create a community
• What is an ecosystem?

  Interaction of a community with abiotic parts
• Why do organisms compete for resources?

  They need the same resources to survive
• What do plants compete for?

  Light, space, water, and mineral ions
• What do animals compete for?

  Space, food, water, and mating partners
• What is an abiotic factor?

  A non-living factor in the environment
• How does light intensity affect a community?

  It affects the rate of photosynthesis
• Why is temperature important for plants?

  It affects the rate of photosynthesis
• Why do plants and animals need moisture?

  Both need water to survive
• How does soil pH affect plants?

  It affects the rate of decay and nutrient uptake
• What is the effect of wind intensity on plants?

  It affects the rate of transpiration
• How do carbon dioxide levels affect plants?

  They affect the rate of photosynthesis
• Why are oxygen levels important for aquatic animals?

  Most fish need high oxygen concentrations
• What is a biotic factor?

  A living factor in the environment
• How does food availability affect a community?

  More food allows for successful breeding
• What happens when a new predator is introduced?

  It can disrupt the existing population balance
• How do new pathogens affect populations?

  They can wipe out populations quickly
• What is competition in a community?

  Better-adapted species outcompete others
• What does interdependence mean in a community?

  Organisms depend on each other for services
• What can happen if a species is removed from a community?

  It can greatly affect other populations
• What characterizes a stable community?

  Biotic and abiotic factors are balanced
• What is parasitism?

  A relationship where one benefits at another's expense
• What is mutualism?

  A relationship where both species benefit
• How does a tapeworm affect humans?

  It steals nutrients and can cause malnutrition
• What is commensalism?

  No damage is caused to either species
• How do lichens benefit from their relationship?

  Algae provide sugars; fungi offer protection
• What are the steps to estimate the number of organisms using quadrats?

  1. Divide the area into equal squares.
  2. Randomly select a square.
  3. Place a quadrat in the square.
  4. Count the organisms in the quadrat.
  5. Repeat and average the results.
  6. Multiply by total squares for estimate.
• What do pyramids of biomass show?

  Relative biomass at each trophic level
• What happens to biomass as you move up trophic levels?

  There is less biomass at higher levels
• How much energy do producers transfer for photosynthesis?

  About 1% of incident light energy
• What percentage of biomass is transferred to the next trophic level?

  Approximately 10%
• Why is not all biomass consumed by animals?

  Some cannot be digested or are waste
• How do humans positively interact with ecosystems?

  By maintaining habitats and raising awareness
• What is a negative human interaction with ecosystems?

  Production of greenhouse gases
• What is eutrophication?

  Excessive growth of plant life depleting oxygen
• How can chemicals from farming affect ecosystems?

  They can leak and cause eutrophication
• What is the role of replanting hedgerows?

  To preserve habitats and biodiversity
• What are positive human interactions with ecosystems?

  Maintaining rainforests and raising public awareness
• What are negative human interactions with ecosystems?

  Production of greenhouse gases and introducing non-indigenous species