Week 9 Thursday

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. Kelp populations would be totally unaffected by the otter population. Kelp populations would decrease due to increased predation by otters. Kelp populations would increase due to an increase in sea urchins. Kelp populations would decrease due to an increase in sea urchins.

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

The sum total of the populations that live in a given area is called a(n): habitat. ecosystem. interaction. community.

community

Which group in a food web is responsible for returning inorganic compounds back to the environment? primary consumers primary producers tertiary consumers decomposers secondary consumers

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 new community None of the answer options is correct. ecological disturbance and a new community

ecological disturbance

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

ecosystem

Keystone species can have significant influences over several populations in a community through their: roles as prey species for predator populations in the community. effect on high amounts of biomass and energy transfer between populations. large body sizes. ability to leave their environment relatively unchanged. avoidance of antagonistic interactions.

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. True False

false

The sequence of species that colonize a recently disturbed area through succession is unpredictable. True False

false

A _____ depicts the flow of carbon through an ecosystem, whereas a _____ depicts the transfer of energy. food web; niche niche; food web food web; trophic pyramid trophic pyramid, food web

food web; trophic pyramid

A species that has a disproportionately large effect on a community is called a _____ species. linchpin central engineer producer keystone

keystone

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

plant species in a community

Organisms that take up inorganic nutrients and convert them to organic molecules such as carbohydrates and proteins are called: predators. heterotrophs. consumers. herbivores. primary producers.

primary producers

The broadest level in a trophic pyramid is primarily composed of: secondary consumers. tertiary consumers. primary consumers. primary producers.

primary producers

Following a disturbance, the process by which species replace each other over time is/are called: ecosystem engineers. succession. competition. disturbances. keystone species.

succession

Energy flow through ecosystems can be depicted using a(n): trophic pyramid. food web. ecosystem. food chain. Calvin cycle.

trophic pyramid.

While food chains show linear energy transfer between organisms, food webs depict more realistically what occurs in an ecosystem. True False

true

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

unique phylogenetic lineages.

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

Not all energy is transferred to the next trophic level.