Foreign invaders have proteins called antigen, which antibodies lock onto to neutralize. The foreign proteins are different from proteins in our own body, so the immune system can recognize them and finally eliminate them.
The nervous system is the major controlling, regulatory, and communicating system in the body. It is the center of all mental activity including thought, learning, and memory. Together with the endocrine system, the nervous system is responsible for regulating and maintaining homeostasis.
<span>b. gravel on the bottom of the aquarium</span>
An ecosystem involves both the biological (plants, animals, human beings) and non-biological (land, water, soil, and atmosphere) community which interacts as a system. More importantly, the living things are very dependent on the abiotic community since it cannot survive by itself. Every animal, plant and human needs the primary physiological needs of water, food and shelter provided by the abiotic system. <span>
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Biotic factors:
Plants
Microorganisms
Macroorganisms
Many reasons including that burning of them (including use in cars) creates greenhouse gases which lead to climate change. There are alternatives becoming available that lower the greenhouse gas emissions...healthier planet!
