NEET BIOLOGY

Detailed explanation-1: -leech, (subclass Hirudinea), any of about 650 species of segmented worms (phylum Annelida) characterized by a small sucker, which contains the mouth, at the anterior end of the body and a large sucker located at the posterior end. All leeches have 34 body segments.

Detailed explanation-2: -Leeches are annelids or segmented worms, and although closely related to the earthworms, are anatomically and behaviourally more specialised.

Detailed explanation-3: -Organisms like headlouse, leech, etc. are found attached to the outer surface of the body of other living organisms (host) and receive nourishment from the host. Therefore, leeches are called sanguivores or ectoparasites, where the organism lives by ingesting fresh blood from the host body.

Detailed explanation-4: -Leeches are segmented parasitic or predatory worms that comprise the subclass Hirudinea within the phylum Annelida. They are closely related to the oligochaetes, which include the earthworm, and like them have soft, muscular segmented bodies that can lengthen and contract.