Earth Science

Life on Earth

Population Size

Study Tip
The prefix a- means “not” or “opposite”, and the root “bio” means alive. Thus, biotic factors are living factors, and abiotic factors are not.

Population Size

  • Biotic and abiotic factors determine the population size.
  • Biotic factors include the amount of food avalible and the number of organisms that use this food.
  • Abiotic factors are temperature, space, water, and sunlight.
  • For a population to grow, there must be enough resources and no major problems.
  • A population may shrink if the biotic and the abiotic factors change.
Study Tip
The prefix a- means “not” or “opposite”, and the root “bio” means alive. Thus, biotic factors are living factors, and abiotic factors are not.

Carrying Capacity

  • The carrying capacity is when the number of births equals the number of deaths.
  • The carrying capacity is the greatest number of organisms of that species that the habitat can support.
  • The carrying capacity depends on biotic and abiotic factors of the habitat.

Limiting Factors

  • Limiting Factors are the parameters that limit the growth of the population.
  • The limiting factors determine the carrying capacity of a species.
  • There are abiotic and biotic factors to how large of a population an environment can support.
  • A limiting factor could be any abiotic or biotic factor.
Carrying Capacity
The size of a population is dependent on many different factors.
Concept Check
  • What is an example of an abiotic factor? A biotic factor?
  • What does the carrying capacity mean?