Which of the following descriptions about the organization of an ecosystem is correct?
Species are grouped in populations, which make up communities.
The simplest grouping of more than one kind of organism in the biosphere is a(an)
Which ecological inquiry method is an ecologist using when he or she enters an area periodically to count the population numbers of a certain species?
The algae at the beginning of the food chain in Figure 3-1 are
An organism that uses energy to produce its own food supply from inorganic compounds is called a (an)
Which of the following organisms does NOT require sunlight to live?
The total amount of living tissue within a given trophic level is called the
What animals eat both producers and consumers?
A snake that eats a frog that has eaten an insect that fed on a plant is a
The trophic levels in Figure 3-2 illustrate
the relative number of individual organisms
Only 10 percent of the energy stored in an organism can be passed on to the next trophic level. Of the remaining energy, some is used for the organism's life processes, and the rest is
eliminated as heat.
What is the process by which bacteria convert nitrogen gas in the air to ammonia?
Carbon cycles through the biosphere in all of the following processes EXCEPT
The movements of energy and nutrients through living systems are different because
energy flows in one direction and nutrients recycle
Which is most likely to be a limiting nutrient in a freshwater pond?
Organisms that break down organic matter and return it to the environment are called _____________.
Decomposers and Detritivores
Of the organisms represented in Figure 3-1, the organisms in the oceans with the smalles total biomass are most likely the _________________.
Water can enter the atmosphere through the process of evaporation and _______________.
Living organisms require nitrogen to make _______________, which are used to build proteins.
Describe the role of algae in ocean food chains.
The algae are autotrophs, the producers at the base of the food chain.
Describe the flow of energy among the following members of an ecosystem:docomposers, autotrophs, heterotrophs, and the sun.
Energy flows from the sun to the autotrophs, and from the autotrophs to the heterotrophs. Energy also flows from the autotrophs and the heterotrophs to the decomposers.
Describe the flow of energy to the owl in Figure 3-2 if the tree provides 1500 calories of energy to the insects.
The insects would provide 10 percent (one tenth) of 1500 calories, or 150 calories, of energy to the shrews. The shrews would provide one tenth of 150 calories, or 15 calories to the owl.
What is the most likely explanation for why Figure 3-2 shows only one organism at its base In what way would an energy diagram be different?
The tree at the base has much more available energy than all the insects that live in it. An energy diagram would be broad at the base like a typical pyramid.
Explain how seepage and transpiration in Figure 3-3 are related.
Water seeps through soil and into the ground water. Roots of trees and plants take the water up through their roots. Plants release the water through the process of transpiration. Both seepage and transpiration are parts of the water cycle.
How does a food web differ from a food chain?
A food chain is a series of steps in which organisms transfer energy by eating and being eaten. A food web is a feeding relationship among the various organisms in an ecosystem that forms a network of complex interactions. A food web links together all the food chains in an ecosystem.