2.1 Species & Population

Species

a group of organisms that share common characteristics and that interbreed to produce fertile offspring.

Habitat

the environment in which a species normally lives.

Niche

How an organism reacts and responds in an enviornment

fundamental niche

How an organism would behave in an ideal enviornment without any limiting factors

realized niche

How an organism actualy responds to the enviornment with limiting factors

abiotic factors

temperature, sunlight, pH, salinity, and precipitation

biotic factors

The interactions between the organisms—such as predation, herbivory, parasitism, mutualism, disease, and competition

population

a group of organisms of the same species living in the same area at the same time, and which are capable of interbreeding.

J curve

Increase of population at an exponential rate.

S curve

Population levels out when it reaches the carrying capaciy

Interspecific competion

Competition between two organisms of different species

Intraspecific competition

Competition between two organisms of the same species

Commensalism

Benefits one species, does nothing for the other

Limiting factors

Factors that limit population growth

Ex:

• Food

• Water

• Predator/Prey interactions

Density-Dependent

• Predator-prey

• Competition

• Disease

Density-Independent

• Natural Disaster

• Unusual Weather