LS7B Week 9

In the example of the giant kelp forests on the Pacific coast, a rise in the otter population would have what effect on the kelp populations?

Kelp populations would increase due to a decrease in sea urchins.

What is generally true about biomass and energy as we move from one trophic level to the next? -They both increase. -Organisms at one trophic level always consume all of the resources from the level below them. -Biomass increases but energy decreases. -Not all energy is transferred to the next trophic level. -All of the energy stored initially in organic molecules by the primary producers will be available to the secondary consumers.

Not all energy is transferred to the next trophic level.

A gardener treats his plants with pesticides, killing any aphids. Once the aphids die, what likely happens to the mutualistic bacteria inhabiting their digestive tracts?

The bacteria would likely die without their mutualistic aphids, as this is an example of an obligate relationship.

Which factors contribute MOST to intraspecific competition?

a species' rate of reproduction and the carrying capacity of the environment

When two species compete for resources, the fitness of:

both species will decline.

A species that is involved in a facultative mutualism with another:

can utilize a variety of different resources

When both participants in a species interaction develop adaptations in direct response to one another, in the long term this could progress into:

coevolution

The sum total of the populations that live in a given area is called a(n):

community

Which of the following is a type of interaction in which BOTH parties are harmed?

competition

Benefits associated with symbiotic relationships might include all of the following EXCEPT:

competitive exclusion

Which group in a food web is responsible for returning inorganic compounds back to the environment?

decomposers

You decide to plant a garden in your backyard. You dig up a strip of grass in a sunny spot. When you have finished digging up the grass, but you haven't planted anything, you have created a(an) _____ in the lawn. -ecological disturbance and a new community -None of the answer options is correct. -ecological disturbance -new community

ecological disturbance

A(n) _____ is a community of organisms and the physical environment it occupies.

ecosystem

Keystone species can have significant influences over several populations in a community through their:

effect on high amounts of biomass and energy transfer between populations.

Predator/prey relationships are always linear, with one species affecting only one other in the community. (T/F)

false

The sequence of species that colonize a recently disturbed area through succession is unpredictable. (T/F)

false

A _____ depicts the flow of carbon through an ecosystem, whereas a _____ depicts the transfer of energy.

food web; trophic pyramid

Imagine that a scientist takes a group of Anolis lizards and introduces them into an enclosure at a research facility in continental South America. He notes that the lizards thrive in this new environment. The fact that Anolis lizards could survive in habitats outside of the Caribbean is a reflection of their _____ niche; their _____ niche is determined by predation and resource availability.

fundamental; realized

A species that has a disproportionately large effect on a community is called a _____ species.

keystone

A mutualism in which the survival of one or both participants is dependent on the other is:

obligate

Which of the following is a good predictor of biodiversity in terrestrial ecosystems? -prey species in a community -pollinator species in a community -predator species in a community -plant species in a community

plant species in a community

Measuring its costs and benefits in terms of energy spent and/or gained, which interaction(s) involve(s) one individual gaining and one individual losing?

predation

Organisms that take up inorganic nutrients and convert them to organic molecules such as carbohydrates and proteins are called:

primary producers

The broadest level in a trophic pyramid is primarily composed of:

primary producers

The _____ of a species is usually the result of predation, competition, and other types of interaction between species.

realized niche

Overlap of niches can be minimized through:

resource partitioning

Which of the following is expected to reduce competition among individuals?

resource partitioning

Measuring its costs and benefits in terms of energy spent and/or gained, mutualism:

results in gain for both individuals

Following a disturbance, the process by which species replace each other over time is/are called:

succession

Close interactions that have evolved over time between species are called:

symbioses

Energy flow through ecosystems can be depicted using a(n):

trophic pyramid

Niches are dynamic, and are affected by interactions among species. (T/F)

true

Symbiotic relationships are subject to natural selection. (T/F)

true

The fact that diverse types of Anolis lizards inhabit (or hunt in) different levels of the tree canopy is the result of the effects of resource partitioning.

true

While food chains show linear energy transfer between organisms, food webs depict more realistically what occurs in an ecosystem. (T/F)

true

While biodiversity includes the number of species in a given area, it also includes: -unique phylogenetic lineages. -overall number of trophic levels in a food web. -amount of primary productivity. -abiotic factors that define the community.

unique phylogenetic lineages