Broader definitions of chemicals or chemical substances can be found, for example: the term 'chemical substance' means any organic or inorganic substance of a particular molecular identity, including â (i) any combination of such substances occurring in whole or in part as a result of a chemical reaction or occurring in nature.
The major groups of worms include various species of flatworm, annelid, ribbon worm, spiny-headed worm, and aschelminth. Worms typically have an elongated, tubelike body, usually rather cylindrical, flattened, or leaflike in shape and often without appendages.
Annelida. . Members of this phylum may be most familiar: the common earthworm, leech and nightcrawler belong to this group. There are three general types of segmented worms. One group is entirely marine (the polychaetes), while the other two groups are either terrestrial or live in freshwater. Members of this phylum may be most familiar: the common earthworm, leech and nightcrawler belong to this group. There are three general types of segmented worms. One group is entirely marine (the polychaetes), while the other two groups are either terrestrial or live in freshwater.