EVERYDAY SCIENCE

Detailed explanation-1: -Roundworms, hookworms, and heartworms are all members of phylum Nematoda, and they are all common canine maladies. Most dogs will become infected with at least one species of nematode at some point in their life.

Detailed explanation-2: -Parasitic nematodes (Fig. 3.41 A, C, D, and E) include heartworms that infect domestic dogs and the hookworms and pinworms that commonly infect small children.

Detailed explanation-3: -The organisms belonging to the phylum Nematoda are also known as “roundworms”. There are 28000 species of Nematoda identified till date. They are unsegmented vermiform animals.

Detailed explanation-4: -Nematodes that commonly parasitise humans include ascarids (Ascaris), filarias, hookworms, pinworms (Enterobius), and whipworms (Trichuris trichiura). The species Trichinella spiralis, commonly known as the ‘trichina worm’, occurs in rats, pigs, bears, and humans, and is responsible for the disease trichinosis.

Detailed explanation-5: -The animals we call “worms” actually belong to nine different phyla. The most common worms are found in three of those phyla: Platyhelminthes, Nematoda, and Annelida. All worms are invertebrates, having no bones. Most worms have head and tail ends, as well as simple organs.