U3- Vocabulary

Biology Unit 3

Population

A GROUP of ORGANISMS from the SAME SPECIES LIVING TOGETHER in ONE PLACE at ONE TIME and INTERBREEDING.

Carrying Capacity

When a population reaches its maximum size.

Exponential Growth

OCCURS WHEN NUMBERS INCREASE BY A CERTAIN FACTOR EACH SUCCESSIVE TIME PERIOD.

Logistic Growth

Occurs when there are factors such as food, water disease and predation that limit the growth of the population.

Immigration

MOVEMENT OF INDIVIDUALS INTO A POPULATION.

Emigration

MOVEMENT OF INDIVIDUALS OUT OF A POPULATION.

Density Dependent Factors

Conditions affected by the size of the population. Nesting sites, food, and water are examples of these factors.

Density Independent Factors

Conditions that affect a population equally regardless of population size. Weather and natural disasters are examples of D.I. factors.

Abiotic Factor

A non-living part of an ecosystem that shapes its environment.

Biotic Factor

A living organism that shapes its environment

Mutualism

Symbiosis that is beneficial to both organisms involved.

Herbivore

An animal that mainly eats plants.

Omnivore

An animal that eats food of both plant and animal origin.

Parasitism

The practice of living as a parasite in or on another organism.

Commensalism

An association between two organisms in which one benefits and the other derives neither benefit nor harm.

Competitive Exclusion

Two species competing for the same resources cannot coexist. The inevitable death of on of them.

Ecological Succession

The process by which the mix of species and habitat in an area changes over time.

Pioneer Species

A group of species that are the first to colonize a new habitat created by a previous disturbance.

Climax Community 

The highest level of ecological succession that a group of plants can reach.

Invasive Species 

An organism that causes ecological or economic harm in a new environment where it is not native

Trophic Level

The position of an organism in the food chain.

Producer

Organisms that make their own food

Heterotroph

An organism that eats other plants or animals for energy and nutrients.

Autotroph

An organism that can produce its own food using light, water, carbon dioxide, or other chemicals.

Consumer (1°, 2°, 3°, 4°)

An organism that cannot produce its own food and must eat other plants and/or animals to get energy.

Detritivore

A type of heterotroph, or organisms that consume dead and decaying organic matter called detritus to obtain energy and nutrition.

Decomposer

An organism that breaks down dead organic material

Food Web

All of the food chains in an ecosystem.