Air pollution is best defined as a. gases or particles present in high enough concentrations in the atmosphere to harm humans, other organisms and structures b. suspended particles of gases that contain small amounts of solids and liquids c. organic chemicals that can vaporize into the air d. any gases in earth's atmosphere in trace amounts e. small particles in the atmosphere arising from volatile organic compounds

Answer;

A. gases or particles present in high enough concentrations in the atmosphere to harm humans, other organisms and structures.

Explanation;

Air pollution is a type of pollution that occurs when harmful or excessive substances such as particulates, gases and biological molecules are introduced into Earth's atmosphere.

The burning of fossil fuels, such as coal, oil, natural gas, and gasoline to produce electricity and power our vehicles is the major cause of air pollution.

organisms that lack symmetry are called asymmetrical and belong to phylum porifera/sponges.

organisms with specialized stinging cells belong to phylum cnidaria. stinging cells are called cnidoblast cells.

cnidarians show two morphological forms : polyp (sessile) and medusa (mobile)

filter feeding is observed in porifera members.  

alternation of generation is observed in coelenterata or cnidaria. there is alternation of asexual polyp form and sexual medusoid form. it is also referred as metagenesis.

hey bro i looked it up on google the structure of the eye-spot in euglena viridie, e. ehrenbergii, and phacus pyriyorme is not as franzé haa described it. the so-called “crystal body” and “lens bodies” were not found in any of the individuals of the species examined by me. as earlier observers have stated, the eye-spot consists simply of a mass of pigment granules arranged in a single layer, and probably embedded in a protoplasmic framework, but the latter could not be seen, and its presence was only inferred from the fact that the pigment granules must be held together in some way, thd the eye-spot as a whole is capable of expansion, and that the pigment granules can be separated from each other.

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