5. why are ecological pyramids shaped as pyramids? (1 point)
because there is a large decrease in the amount of energy or biomass as you move from one trophic level up to the next
because the movement of energy through the biosphere follows a path similar in shape to a pyramid
because decomposers form a wide base of support at the bottom of a food web similar to the base of a pyramid
because a pyramid represents a stable building form that is similar to the structure of a stable ecosystem
6. what is true of matter in ecosystems? (1 point)
nonliving things are essential for carrying out the chemical transformation of certain elements so that living things can use them.
living things can recycle elements within an ecosystem as long as decomposers are present.
matter flows in a one-way direction with a 10% loss at each move up in trophic level.
elements continuously cycle between the physical environment and living organisms.
7. which of the following is a food chain in the food web shown in figure 3–4?
(1 point)
tree, rabbit, hawk, snake
grass, grasshopper, snake, hawk
grass, caterpillar, robin, hawk
tree, deer, mountain lion, fox

Organisms from the higher trophic levels consume organisms from the lower trophic levels. During this process, energy is lost as metabolic heat. Primary producers on the first trophic level contain the greatest amount of energy originally from the sunlight. The next trophic level belongs to primary consumers that consume primary producers which result in less energy. Similarly, secondary consumers eat primary consumers, and energy is lost again. The highest trophic level is tertiary consumers and they contain the least amount of energy.

Q6. The answer is Elements continuously cycle between the physical environment and living organisms.

Biogeochemical cycles are pathways by which chemical substances move through biosphere and geosphere (lithosphere), as well as atmosphere and hydrosphere. In these cycles elements are recycled, they are not lost. They continuously cycle between the physical environment and living organisms.

Q7. The answer is grass, grasshopper, snake, hawk.

Figure 3-4 is not attached, however, the logic food web among all choices wood be: grass, grasshopper, snake, hawk.

Grass belong to the producents. Grasshopper is a primary consumer and it eats producent grass. Snake, as a secondary consumer, eats the primary consumer grasshopper. A terciary consumer hawk eats the secondary consumer snake.