Unit 2

Question 1

Behavioral adaptations

Answer 1

something an animal does usually in response to some type of external stimulus in order to survive.

Question 2

Biodiversity

Answer 2

the variety of life in the world or in a particular habitat or ecosystem.

Question 3

Ecological tolerance

Answer 3

the range of abiotic conditions in which a species can survive.

Question 4

Ecosystem services

Answer 4

Ecosystem services are the many and varied benefits to humans provided by the natural environment and from healthy ecosystems. Such ecosystems include, for example, agroecosystems, forest ecosystem, grassland ecosystems, and aquatic ecosystems.

Question 5

Generalist species

Answer 5

Species that can live in many different types of environments, and have a varied diet

Question 6

Genetic adaptations

Answer 6

A biological characteristic with a heritable basis that improves reproduction and/or survival and results from evolution by natural selection.

Question 7

Genetic diversity

Answer 7

the range of different inherited traits within a species.

Question 8

Habitat diversity

Answer 8

the range of habitats present in a region.

Question 9

Indicator species

Answer 9

an organism whose presence, absence or abundance reflects a specific environmental condition.

Question 10

Island biogeography

Answer 10

a field within biogeography that examines the factors that affect the species richness and diversification of isolated natural communities.

Question 11

Supporting species

Answer 11

a species on which other species in an ecosystem largely depend, such that if it were removed the ecosystem would change drastically.

Question 12

Natural climate changes

Answer 12

the sun’s intensity, volcanic eruptions, and changes in naturally occurring greenhouse gas concentrations.

Question 13

Pioneer species

Answer 13

Pioneer species are hardy species that are the first to colonize barren environments or previously biodiverse steady-state ecosystems that have been disrupted, such as by wildfire

Question 14

Primary succession

Answer 14

happens when a new patch of land is created or exposed for the first time.

Question 15

Secondary succession

Answer 15

a previously occupied area is re-colonized following a disturbance that kills much or all of its community

Question 16

Specialist species

Answer 16

animals that require very unique resources.

Question 17

Species diversity

Answer 17

the number of different species present in an ecosystem and relative abundance of each of those species.

Question 18

Species richness

Answer 18

the number of species within a defined region

Question 19

How many species are estimated to exist on Earth?

Answer 19

10 million

Question 20

Two savanna communities both contain 15 plant species. In community A, each of the 15 species is represented by 20 individuals. In community B, 10 of the species are represented by 12 individuals; the remaining 5 species are each represented by 3 individuals. Which statement best describes the two communities?

Answer 20

Community A has a higher species evenness.

Question 21

Phylogeny is

Answer 21

the branching pattern of evolutionary relationships

Question 22

Which of the following is used to calculate Shannon’s Index of diversity?
I. The proportion of individuals in each species

II. The total number of species

III. The number of individuals in each species

Answer 22

l and II only

Question 23

Which evolutionary effect results in reduced genetic variation in a community?

Answer 23

The founder effect

Question 24

Which of the following is the best example of critical habitat?
Many species of hawk rely on trees to spot prey and would be less successful at hunting if there was logging.

Ponds are preferred foraging grounds for bull frogs, and if they were developed on, the frogs would need to forage in nearby rivers, which have less available food.

Wetland and riparian ecosystems are vital foraging and breeding grounds for the endangered whooping crane.

Alaska Native American tribes sustain their communities with wild salmon, and the salmon rely on specific river habitats to repopulate.

Nomads in the Sahara have long relied on scattered oases as a source of food and water for their camel herds.

Answer 24

Wetland and riparian ecosystems are vital foraging and breeding grounds for the endangered whooping crane.

Question 25

What is the approximate proportion of amphibian species worldwide that are at risk of extinction?

Answer 25

1 in 3

Question 26

How does the 6th mass extinction significantly differ from the other 5 mass extinctions that have occurred throughout the history of Earth?

Answer 26

Human activities (overhunting, habitat destruction, greenhouse gases, etc.) are the primary contributing factor in the 6th mass extinction, which was not the case for the other events.

Question 27

In the 1960s, Robert MacArthur and E.O. Wilson came up with one of the most prominent theories in the field of ecology—Island Biogeography Theory. This theory describes the balancing of which two processes?

Answer 27

Immigration and extinction

Question 28

what are the 5 fingers of evolution?

Answer 28

small population, non-random mating, mutualism, gene flow, adaptation.

Question 29

The gray wolf is a keystone species because..

Answer 29

They cull herds of bison, elk, and caribou
They keep coyote populations down
They provide meat for scavengers such as ravens and bald eagles

Question 30

one reason some people were opposed to reintroduction of gray wolves to Yellowstone National Park was…

Answer 30

Leave park and attack rangers
They would kill too many big game animals
Mining and logging companies would have to halt operations

Question 31

Ecological benefits of reintroducing wolves to Yellowstone include..

Answer 31

Growth aspen and cottonwoods near stream banks
Decrease in coyote population

Question 32

What is not an economic service provided by forests?

Answer 32

Mining

Question 33

Old-growth forests can be described by all of the following except..

Answer 33

A clear forest floor