science chapter 4

If the primary producers produce 50,000 energy units, about how much of this energy is available to the secondary consumers

500 energy units

dentrification

Conversion of nitrates into nitrogen gas, which is released into the atmosphere

Photosynthesis

Plants use the sun's energy to convert water and carbon dioxide into sugars

nitrogen fixation

Process of converting nitrogen gas into ammonia

To represents all of the energy in the food chain. which modifications to the arrows, would be MOST useful to include

add arrows from each organism to its environment, to show the energy lost as heat

limiting nutrient

any nutrient whose supply limits productivity is called what

consumers

are organisms that rely on other organisms for energy and nutrients

primary producers

are the first producers of energy-rich compounds that can be used later by other organisms

a group of students is developing models of the carbon cycle and the nitrogen cycle. How should cellular respiration be included in these models.

cellular respiration should be included in the carbon cycle only because the process transfers carbon from the biosphere to the atmosphere

nutrients

elements an organism needs to live

a pond ecosystem is home to a community of algae, insects, snails and a variety of fishes and birds. the pond is part of a wildlife preserve and is adjacent to a new housing development. Which of these events would most likely cause the greatest change to the pond ecosystem?

fertilizer is washed regularly into the pond from nearby lawns

How does energy flow through an ecosystem?

in a one way stream, from primary producers through various consumers

food chain

is a series of organisms in which energy is transferred from one organism to another

a carnivore obtains energy by eating other animals. which of the following shows the process by which energy flows to a carnivorous animal

light energy-plant-herbivore-carnivore

biogeochemical cycle

matter flows from one trophic level to another, and elements are recycled within and among ecosystem

heterotrophs

must acquire energy from other organisms, usually by eating them

autotrophs

organisms that can capture energy from nonliving sources and convert it into forms living cells can use

Which of explains the role of plants in the carbon cycle

plants transfer carbon dioxide in the atmosphere to carbohydrates in the biosphere

Chemosynthesis

process in which chemical energy is used to produce carbohydrates

scientists use various models, such as energy pyramids, to study the transfer of energy in ecosystems. They use other models, such as biochemical cycles, to study the transfers of matter in ecosystem. Which describes biogeochemical cycles, but not energy pyramids?

show an endless cycle

The diagram is a pyramid of biomass for a meadow ecosystem. the triangular shape of the diagram is useful for explaining which relationship among the trophic levels

the amount of living organic matter decreases at each trophic level in this ecosystem

what can be inferred about the source energy for the algae

the energy source is sunlight, which the algae take in by photosynthesis.

Phytoplankton

tiny floating algae

biomass

total amount of living tissue within a given trophic level