Characteristics of Communities

Question 1

What is ecology?

Answer 1

The study of interactions of organisms with another and their physical environment.

Question 2

What are abiotic factors?

Answer 2

Nonliving factors that affect and surround the organisms (water, air, sunlight, dirt)

Question 3

What are biotic factors?

Answer 3

Living organisms

Question 4

What is a population?

Answer 4

All the living organisms of one species (interbreeding) in one area.

Question 5

What is a community?

Answer 5

All living organisms in a given area

Question 6

What is a niche?

Answer 6

Role the organism plays in the ecosystem

Question 7

What is a biosphere?

Answer 7

The portion of earth in which all living things exist.

Question 8

What is an ecosystem?

Answer 8

The community (all the living organisms in a given area) and the abiotic factors.

Question 9

What is biodiversity?

Answer 9

Number of different species and their abundance.

Question 10

What is species richness?

Answer 10

The number of species living in 1 habitat

Question 11

What is a habitat?

Answer 11

The natural home of a living organism

Question 12

What happens to species richness as you approach the equator?

Answer 12

It increases

Question 13

What is a foundation species?

Answer 13

A “base” organism. It is abundant and maintains the habitat

Question 14

What is a keystone species?

Answer 14

The main source of biodiversity that can influence the presence of other organisms

Question 15

What is an invasive species?

Answer 15

A non-native species that when introduced in a specific habitat can have bad effects and alter the community.

Question 16

What is interdependence?

Answer 16

the dependence of two or more organisms on each other.

Question 17

What is interspecific competition?

Answer 17

When multiple species compete for the same space and resources.

Question 18

What is intraspecific competition?

Answer 18

When individuals from the same species compete

Question 19

What happens during eutrophication?

Answer 19

There is very low Dissolved Oxygen (D.O.) and very high Biological Oxygen Demand (B.O.D.).

1. Excessive nutrients are flushed from land into the water
2. These pollutants cause lots of algae growth
3. Algae blooms and prevents O2 from reaching other plants. The plants die and the O2 in the water is low.
4. Dead plants are broken down by decomposers which use up even more O2.
5. O2 levels reach a point where life is not possible.

Question 20

How is population regulated?

Answer 20

Number of births + immigration = number of deaths and emigration

Question 21

What is population density?

Answer 21

Population size

Question 22

What is immigration?

Answer 22

Organisms enter an area

Question 23

What is emigration?

Answer 23

Organisms leave an area

Question 24

What happens during exponential growth (J curve)?

Answer 24

Population grows unchecked

Question 25

What happens during logiStic growth (S curve)?

Answer 25

Pressure begins because of environmental resistance (rainfall, acidity, food, competition)

Question 26

What are limiting factors?

Answer 26

Environmental factors that put pressure on population

Question 27

What is the carrying capacity?

Answer 27

the number of organisms that an environment can support without environmental decay. Helps pop. level our and become stable.

Question 28

What is B.O.D.?

Answer 28

A measure of the amount of oxygen required to remove waste. (How much oxygen the decomposers need)

Question 29

What is D.O.?

Answer 29

the amount of oxygen available to living aquatic organisms

Question 30

What are density-dependent factors?

Answer 30

Factors that depend on population size (food supply, parasites, disease, competition, predation)

Question 31

What are density-independent factors?

Answer 31

Factors that do not depend on population size and only exist because of the environment (rainfall, floods, acidity, drought)