APES test - Primary Productivity and Energy Flow

biomass pyramid

Diagram representing the biomass in each trophic level of an ecosystem Each higher trophic level contains less biomass than the previous trophic level; also related to the abundance of organisms at each trophic level

dissolved Oxygen

Measure of water quality indicating free oxygen dissolved in water; important for fish and other aquatic animals

light and photosynthesis in water

Most red light is absorbed in the upper 1m of water, and blue light only penetrates deeper than 100m in the clearest water. photosynthesizers have had to adapt mechanisms to address the lack of visible light.

biomass

The dry weight of all organic matter within the organisms of a food chain/web

net primary productivity

The energy available to consumers; determined by subtracting the energy used by plants from the total energy transformed by the process of photosynthesis (gross primary productivity).

gross primary productivity

a measure of the total amount of light energy that was captured and converted into chemical energy (organic compounds) during photosynthesis (includes the accumulated mass on the plant and the mass energy the plant has used to grow/stay alive)

food web

a model of an interlocking pattern of food chains that depicts the flow of energy and nutrients in two or more food chains.

what affects DO

amount of decomposition and DO used by decomposers, temperature (warm temp, lower DO)

primary consumers or herbivores

animals that eat producers, feeding mostly on green plants

consumers or heterotrophs

cannot produce their own nutrients

decomposers

consumers that release nutrients from the dead bodies of plants and animals and return them to the soil, water, and air for reuse by producers, mushrooms, for example.

Energy flow in a food web/chain __________ at each succeeding organism in a chain or web.

decreases

resource (niche) partitioning

division of resources to reduce interspecific competition (between two different species- owl and hawk)

detritus feeders

feed on the wastes or dead bodies of other organisms.

The greater the number of trophic levels in a food chain, the ________ loss of usable energy.

greater

ecological pyramid

helps one visualize the fact that in an ecological system there needs to be many producing organisms at the bottom of the pyramid to be able to sustain just a couple of organisms at the top (not an effective transfer because not every organism / not every part of each organism is eaten)

what happens to most energy from the sun?

it is reflected by ozone or clouds

laws of thermodynamics

laws that explain the loss of energy that occurs when energy moves from lower to higher trophic levels

Where does the energy go as it moves through a food chain?

lots of the energy is used for life functions, such as manufacturing food or breaking down/burning food molecules. Thermal energy (heat) is produced as a result of the burning of these food molecules.

Producer or autotroph

make the nutrients they need from compounds and energy obtained from their environment through a process called photosynthesis

in the transfer of energy from one trophic level to the next, __________ of the energy is passed on.

only about 10%

numbers pyramid

shows how many organisms are needed at each trophic level (The total number of plants in a particular area would generally be higher than the number of herbivores that the plants support and the number of herbivores would be higher than the number of higher order carnivores.)

trophic level

the level assigned every type of organism in an ecosystem, depending on its source of food or nutrients.

The pyramid of energy flow visualizes ______________________________________________. The lower levels of the trophic pyramid support ________ organisms.

the loss of usable energy through a food chain; more

photosynthesis

the process by which plants produce nutrients from solar energy. They convert carbon dioxide, water, and energy to glucose and oxygen.

aerobic respiration

uses oxygen to convert glucose (or other organic nutrient molecules) back into carbon dioxide and water