Chapter 25 Flashcards
ecology
involves the relationship of organisms to each other and to their environment
populations
groups of individuals of the same species
plant community
unit composed of all the species of plants occurring in a given area
biotic community
unit composed of all the populations of organisms in a given area
populations vary in
density, in genetic diversity, numbers, and in the total mass of individuals
density
number of individuals per unit volume
biomass
total mass of the living individuals present
communities
composed of populations of different species living together in the same place
producers
capable of carrying on photosynthesis, they store energy that may be released by other organisms
Primary consumers
feed directly on producers
secondary consumers
feed on primary consumers
decomposers
break down organic materials to forms that can be reassimilated by the producers
Trophic efficiency
the percentage of available energy actually transferred from one trophic level to the next
life history
composed of traits that control a species survival and reproduction
Natural cycles
- Water cycle
- carbon cycle
- nitrogen cycle
