Population Ecology

• What is a species?

  A group of organisms capable of interbreeding, producing fertile offspring.
• What defines a population?

  A group of the same species that occupies the same habitat at the same time.
• What is a community in ecological terms?

  Groups of different species populations that interact with each other within a specific habitat.
• What is a habitat?

  The environment in which a plant/animal species normally occurs.
• What does natality refer to in population ecology?

  The increase of a population due to the number of births in a given season.
• How is population size defined?

  Number of individuals found in a specific population at a specific time.
• What is mortality in the context of population ecology?

  The death rate within a population.
• What is immigration in population ecology?

  One-way movement of species into a specific area.
• What is emigration?

  One-way movement of a species out of a specific area.
• What factors influence population size?

  Immigration, emigration, natality, and mortality.
• What is the equation for calculating population change?

  Population change = (Births + Immigration) - (Deaths + Emigration)
• What does it mean if births and immigration are greater than deaths and emigration?

  Population size would increase.
• What does it indicate if births and immigration are less than deaths and emigration?

  Population size would decrease.
• What is a closed population?

  A population where only natality and mortality influence population size (no migration taking place).
• How is population density defined?

  The number of individuals in a population per unit area.
• What are the direct methods used to determine population size?

  • Census
  • Aerial photography
• What are the indirect methods used to estimate population size?

  • Mark and recapture
  • Quadrants
• What is the mark and recapture method?

  It involves capturing, marking, and releasing a sample of the population, then recapturing to estimate size.
• What is the Petersen Index Formula used for?

  To determine the size of the population.
• In the Petersen Index Formula, what does N represent?

  N represents the total number of individuals in a given population.
• In the Petersen Index Formula, what does M represent?

  M represents the number of animals captured and marked in the first sample.
• In the Petersen Index Formula, what does C represent?

  C represents the number of individuals captured in the second sample.
• In the Petersen Index Formula, what does R represent?

  R represents the number of individuals marked in the second sample.
• What precautions should be taken when using the mark and recapture method?

  The sample must be large enough, markings must last, and should not harm organisms.
• What is environmental resistance in population ecology?

  Factors that contribute to fluctuations in population size, limiting growth.
• What is carrying capacity?

  The maximum population size that can be sustained over time by a particular environment.
• What happens when the carrying capacity is exceeded?

  Environmental resistance increases, and population numbers decrease.
• What are density dependent factors?

  Factors that have a direct correlation to the size of the population in an area.
• How does food availability affect population size?

  As population increases, food resources become less available, leading to competition and decline.
• How does space affect population size?

  Lack of space reduces the birth rate in females, leading to a decrease in population size.
• How does predation affect population size?

  As prey population increases, predators increase, leading to a cyclical fluctuation in both populations.
• What are density independent factors?

  Factors that limit the size of populations regardless of the number of individuals.
• What is geometric growth also known as?

  Exponential growth.
• What characterizes geometric growth curves?

  They are J-shaped and characteristic of microorganisms and insects.
• What are the three distinct phases of geometric growth curves?

  Lag phase, exponential growth phase, and extinction/death phase.
• What is a logistic growth curve also known as?

  Sigmoid growth curve.
• What characterizes logistic growth curves?

  They are S-shaped and do not exceed carrying capacity.
• What are the four distinct phases of logistic growth curves?

  Lag phase, exponential growth phase, decelerating growth phase, and equilibrium phase.
• What is predation?

  Predators actively hunt, kill, and consume prey to meet their energy requirements.
• What is competition in ecological terms?

  An interaction between individuals in a community over scarce resources.