Question

1. identify the trophic level with the highest amount of available energy in an ecosystem.
2. explain how the laws of thermodynamics relate to the amount of energy available in an ecosystem.
3. fill in the blank: in a food chain or food web, arrows represent the transfer of

in an ecosystem.

1. identify the ultimate source of energy in an ecosystem.
2. using the food web to the right, identify a producer in this ecosystem.
3. using the food web below, identify a tertiary consumer in this ecosystem.

Explanation:

1. Producers (like plants) have the highest available energy as they capture energy from the sun through photosynthesis and form the base of the food - chain.
2. The first law of thermodynamics (conservation of energy) means energy is transferred in an ecosystem, not created or destroyed. The second law (entropy increases) implies that with each energy transfer, some energy is lost as heat, reducing the amount of available energy at higher trophic levels.
3. In a food - chain or food - web, arrows represent the transfer of energy and nutrients as one organism consumes another.
4. The ultimate source of energy in an ecosystem is the sun. Producers use sunlight for photosynthesis to convert light energy into chemical energy.
5. In the given food - web, plants, seeds, and needles are producers as they can make their own food through photosynthesis.
6. A tertiary consumer is an organism that eats secondary consumers. In the food - web, the red fox can be considered a tertiary consumer as it may eat secondary consumers like the weasel which in turn eat primary consumers.

Answer:

1. Producers
2. The first law shows energy is conserved and transferred, the second law shows energy is lost as heat in transfers reducing available energy at higher levels.
3. Energy and nutrients
4. The sun
5. Plants, seeds, and needles
6. Red fox