Answer:
A
Explanation:
The dead matter from organisms such as plants and animals that die need to be recycled so the nutrients in the matter are released and used up by other organisms. This is how sustainability is achieved in ecosystems through a cyclical nature of nutrients flow. Decomposition of the dead matter is done by decomposers such as fungi and bacteria. Without them, the dead matter would accumulate while the soil would lack nutrients for plants to grow and for other bacteria to utilize for energy. This would affect the rest of the food chain/web causing the ecosystem to collapse.
During nitrogen fixation, bacteria breaks nitrogen gasses down into a usable form for plants.
There are 7 levels of classification for Animals. Kingdom, Phylum, Classes, Order, Families, Genus, and Species.
