Answer:
1.) D, biotic and abiotic parts
2.) Trophic level
3.) 90%
Explanation:
1.) Ecosystem refers to the interaction of the biotic components of a community with each other, and also with the abiotic components. Biotic components refers to the part of the ecosystem that has life in them e.g plants, animals and microbes while the abiotic components refer to the part that have no life in them e.g. climate, temperature, soil, sun etc. Hence, an ecosystem consists of the biotic and abiotic parts.
2.) Organisms in an ecosystem derive energy by feeding on one another. This feeding chain is called FOOD CHAIN. However, organisms exist in each step of the food chain. This step occupied by organisms is referred to as FOOD LEVEL or TROPHIC LEVEL. The first trophic level is occupied by organisms called PRODUCERS, followed by primary, secondary and tertiary CONSUMERS.
3.) As organisms feed on one another in the food chain. They obtain energy for their life processes. However, as one organism consumes another, about 90% of the energy is lost to heat when the organism performs its own biological/metabolical functions. Only about 10% of the energy is available for the next trophic level. Hence, as the trophic level increases, the available energy decreases.
