Ecosystems

• What is the definition of a habitat?

  The environment in which an organism lives
• How is a population defined in ecological terms?

  The total number of organisms of the same species living in the same geographical area
• What is a community in ecological terms?

  The populations of all the different species that live in the same habitat
• What does the term biotic refer to?

  The living organisms in an environment
• What are abiotic factors?

  The nonliving parts of an environment
• What is an ecosystem?

  Both the biotic and abiotic parts of an environment and how they interact
• What do living organisms require from their surroundings?

  A supply of materials such as water
• Why do living organisms have to compete with each other?

  Because resources are often in short supply
• What resources do plants compete for?

  Light, space, water, and mineral ions in the soil
• What resources do animals compete for?

  Food, water, mating partners, and territory
• What is interdependence in an ecological context?

  The dependence of different species on each other
• How do lions and zebras demonstrate interdependence?

  Lions eat zebras, showing a predator-prey relationship
• How do plants depend on animals?

  Many plants depend on bees for pollination and birds for seed dispersal
• What happens if a species disappears from a community?

  It can affect the whole community, leading to food shortages for other species
• What is a stable community?

  A community where the populations of different species remain fairly constant
• What does it mean for populations to be in balance in a stable community?

  Populations of organisms are balanced with each other and with abiotic resources
• What abiotic resource is mentioned as being important in a stable community?

  Water
• What are the consequences of interdependence in a community?

  • Species depend on each other for food and resources
  • Disappearance of one species can affect the entire community
  • Example: Without bees, many plants would not be pollinated
• What are the two main types of factors that affect a community?

  Biotic and abiotic factors
• What are biotic factors?

  Biotic factors are the living parts of an environment.
• What are abiotic factors?

  Abiotic factors are the nonliving parts of an environment.
• What are the four different biotic factors that can affect a community?

  1. Availability of food
  2. Arrival of a new predator
  3. Competition between species
  4. New pathogens
• How does the availability of food affect a community?

  If the availability of food falls, then the number of organisms in that community will also fall.
• What effect can the arrival of a new predator have on a prey species?

  The arrival of a new predator can cause the population of a prey species to fall.
• How can competition between species affect populations?

  If a species is outcompeted, its population can fall to the point of extinction.
• What happens if a new pathogen emerges in a community?

  If an infectious disease emerges and spreads, it can wipe out a population of a species.
• What are the seven different abiotic factors that can affect a community?

  1. Light intensity
  2. Temperature
  3. Water
  4. pH and mineral content of the soil
  5. Wind intensity and direction
  6. Carbon dioxide levels
  7. Oxygen levels
• How does light intensity affect plants?

  If light intensity is too low, the rate of photosynthesis falls, and plants grow more slowly.
• What impact does temperature have on species distribution?

  A change in temperature can cause the distribution of species to change, leading to migration or disappearance.
• Why is water considered a major abiotic factor?

  Both plants and animals need water to survive.
• How does soil pH affect plant growth?

  Many plants cannot grow in soil that is too acidic or too alkaline.
• What minerals do plants need from the soil?

  Plants need certain minerals, such as nitrate, to make amino acids for proteins.
• How can wind intensity and direction affect plants?

  Strong winds can cause plants to lose water, affecting their growth.
• What should you be able to describe by the end of the video on adaptations?

  How organisms are adapted to living in the natural environment
• Why are carbon dioxide and oxygen important for plants and animals?

  Carbon dioxide is needed for photosynthesis, while oxygen is needed for respiration.
• What types of adaptations are mentioned in the study material?

  Structural, behavioral, and functional adaptations
• How can low levels of dissolved oxygen in water affect aquatic organisms?

  Low levels of dissolved oxygen can be harmful to aquatic organisms, such as fish.
• What is meant by an extremophile?

  An organism adapted to live in extreme conditions
• Where can students find questions on biotic and abiotic factors?

  In the vision workbook linked in the video.
• Are specific examples of adaptations required in the exam specification?

  No, specific examples are not required