Unit 2 Key Terms

Question 1

Adaptation

Answer 1

a new trait that increases an organism’s fitness (ability to survive and reproduce)

Question 2

Biodiversity

Answer 2

all the different kinds of life you’ll find in one area

Question 3

Ecological Diversity

Answer 3

The variety of terrestrial and aquatic ecosystems found in an area or on the earth

Question 4

Ecological Niche

Answer 4

The totality of an organism’s adaptions, its use of resources, and the lifestyle to which it is fitted.

Question 5

Evolution

Answer 5

(natural selection)
change in the genetic makeup of a population of a species in successive generations; if continued long enough, it can lead to the formation of a new species; affects populations, not individuals

Question 6

Extinction

Answer 6

Complete disappearance of a species from the earth. It happens when a species cannot adapt and successfully reproduce under new environmental conditions or when a species evolves into one or more new species.

Question 7

Generalist Species

Answer 7

a species that has a broad niche and is able to adapt to many environmental conditions. They do not have a limited diet and are able to survive by using a variety of resources.

Question 8

Genetic Diversity

Answer 8

the variety of genes that the variety of species on earth contains; it enables life on earth to adapt to and survive dramatic and environmental changes.

Question 9

Habitat

Answer 9

the natural home or environment for a human, animal, or organism.

Question 10

Natural Selection

Answer 10

organisms that are better adapted to their environment survive and reproduce more offspring
Individuals with adaptations pass them on to offspring & individuals without adaptations die off, which leads to the entire population having the adaptation over time

Question 11

Non-native Species

Answer 11

species that migrate into an ecosystem or are. deliberately or accidentally introduced into an ecosystem by humans

Question 12

Specialist Species

Answer 12

species with a narrow niche and is not adaptable to change in their environment

Question 13

Speciation

Answer 13

Formation of two species from one species because of divergent natural selection in response to changes in environmental conditions; usually takes thousands of years.

Question 14

Species

Answer 14

A group of closely related and interbreeding living things

Question 15

Species Diversity

Answer 15

the number of different species in an ecosystem and the balance or evenness of the population sizes of all species in the ecosystem

Question 16

Species Evenness

Answer 16

a measure of how all of the individual organisms in an ecosystem are balanced between the different species
- indicates if there are one or two dominant species, or if population sizes are well balanced

Question 17

Species Richness

Answer 17

total number of different species found in an ecosystem
- high (r) is generally a good sign of ecosystem health (more species means more quality resources like H2O & soil)

Question 18

Theory of Island Biogeography

Answer 18

After an island is formed, it will soon be inhabited by organisms. The size and distance from the mainland affect the number of species that the island can support. Immigration rates and extinction rates also play a hand in the number of species on the island

Question 19

Ecological Succession

Answer 19

the gradual change an ecosystem experiences over time until it reaches stability
A series of predictable stages of growth that a forest goes through

Question 20

Pioneer Species

Answer 20

appear first, when the ground is simply bare rock or bare soil after a disturbance

Question 21

Population

Answer 21

a group of organisms of the same species, living in the same area

Question 22

Primary Ecological Succession

Answer 22

Succession that starts with an essentially lifeless area where there is no soil or bottom sediment in an aquatic area

Question 23

Range of Tolerance (ecological tolerance)

Answer 23

(range where organisms survive, grow, and reproduce)
range of conditions such as temperature, salinity, pH, or sunlight that an organism can endure before injury or death results
Species and individual organisms both have a range of tolerance for all the different environmental conditions
of their habitat

Question 24

Resilience

Answer 24

the ability of an ecosystem to return to its original conditions after a major disturbance (wind storm, fire, flood, clear-cutting, etc.)

Question 25

Secondary Ecological Succession

Answer 25

begins in an area where the natural community of organisms has been disturbed or destroyed, but the soil remains.