Question

calories at one level, only 1,000 are transferred to the next. this 10% energy and material transfer rule can be depicted with an ecological pyramid that looks like the one below.
this pyramid helps one visualize the fact that in an ecological system there need to be many producing organisms at the bottom of the pyramid to be able to sustain just a couple of organisms at the top. in looking at the pyramid, can you guess how much larger the volume of each layer is as compared to the one just above it? take a guess. it might not look like it but they are close to 10 times larger.
a basic pyramid shape often represents a typical food chain or food web. the pyramid represents the decrease in the amount of energy, the number of organisms and the biomass from the producer to the high - order consumer levels. the decrease in the numbers and in the biomass represent the fact that, due to energy loss, fewer organisms can be supported at each successive trophic level.
pyramid of energy
energy is lost between each link in a food chain. much of the potential energy at each level never reaches the next level. where does the energy go as it moves through a food chain? some of the energy that enters a food chain is used as each organism carries out its life functions (i.e foraging, metabolic processes, reproduction, predator/prey behavior, etc.). producers manufacture their own food source directly from sunlight by the process of photosynthesis. in order to carry out life functions, consumers acquire energy through the ‘burning’ or breaking down of food molecules they consume (eat). thermal energy (heat) is produced as a result of the burning of these food molecules. more than half of the energy from each food molecule is lost as heat. only about 10% - 20% of energy at each trophic level is available to pass on to the next level. in other words, at each level there is only about 10% available energy to put on new biomass (growth).
pyramid of numbers
the loss of energy at each trophic level also explains why there are usually fewer organisms in each higher trophic level. the total number of plants in a particular area would generally be higher then the number of herbivores that the plants support and the number of herbivores would be higher than the number of higher order carnivores.
pyramid of biomass
biomass is the total mass of dry organic matter per unit of area. each higher trophic level contains less biomass than the previous trophic level. therefore a diagram or graph that represents the amount of biomass at each trophic level would also produce the basic pyramid shape. biomass is related to the abundance of organisms at each trophic level.
human impact on food chains and webs
humans have the ability to have a great impact on ecosystems. living organisms are a significant portion of any ecosystem, therefore any activity that affects an ecosystem is also likely to affect the organisms within that ecosystem. if organisms are affected the food chains/webs that the organisms are a part of will also feel the effects

Explanation:

The content is about ecological pyramids (energy, numbers, biomass) and food chains/webs, which falls under Biology (a subfield of Natural Science) as it deals with ecological systems and organisms' energy flow.

Answer:

Natural Science - Biology