37.14--37.23 Flashcards
(12 cards)
Which of the following converts inorganic components of the ecosystem into organic substances?
Producers
What is meant by the following phrase: All organisms “borrow” chemical elements from the earth?
This phrase refers to the fact that the elements in organic matter are eventually returned to the
soil because when an organism dies, decomposers in the soil break down its organic matter.
The two processes that help to sustain and drive ecosystems are ____________ and
______________.
Energy Flow, Chemical Cycling
Net primary productivity is explained by which of the following?
The amount of biomass removed for the plants’ own cellular respiration
Ecosystems vary in their energy efficiency, but as a general rule, ____________% of the energy available at one level is transferred to the next trophic level.
10%
Why do ecosystems tend to have very few tertiary and quaternary predators while having an abundance of different producers and primary consumers?
Only a fraction of the energy in biomass is available to consumers in subsequent trophic levels.
For example, it takes a lot of mice to maintain a population of owls. As such, the population
of tertiary and quaternary consumers is limit
Humans can learn something about our own sustainability from the fact that available energy decreases as you go up in trophic levels. What is a simple solution (that would require no new technology) for how humans could feed more of our species?
We could eat at a lower trophic level (vegetarianism) and have more energy available to us
A quote by a scientist reads: “Three hundred trout are needed to support one man for a year. The trout, in turn, must consume 90,000 frogs that must consume 27 million grasshoppers that live off 1,000 tons of grass.” What is this quote trying to make us aware of?
The quote is trying to make us aware of the idea that less energy is available at successive
trophic levels.
True or false: Certain elements are continuously cycled between biotic and abiotic portions of an ecosystem. If false, make it a correct statement.
True
List four components of the biogeochemical cycles that replenish the abiotic reservoir. Refer to Figure 37.18 on page 753 of your textbook.
a. Nutrients available to consumers
b. Consumers feed on producers
c. Release of chemicals into the environment by producers and consumers
d. Breakdown of organic matter by decomposers
List the sources of carbon in the abiotic reservoirs.
It exists as CO2 in the atmosphere and in fossil fuels and sedimentary rocks. It is also dissolved
in water as various carbon compounds that include CO2
Briefly explain the roles of cellular respiration and photosynthesis in the carbon cycle.
They are chemical opposites of each other: photosynthesis removes carbon from the abiotic
reservoir and incorporates it into organic matter, and cellular respiration removes carbon from
the biotic reservoir and returns it to the abiotic reservoir.
