Question

What are the main characteristics of these?
platyhelminth
nematode
arthropod
chordata

I know first two are worms, third insects and fourth include humans. but what's the main characteristic of each?

Answer 1

1. Platyhelminthes also known as 'flatworms' are a phylum of triploblastic acoelomate invertebrate animals. The word platyhelminthes comes from the Greek words 'platy' meaning flat and 'helmins' meaning worm.Their worm like bodies are soft, unsegmented, dorsoventrally flattened with bilateral symmetry and resemble ribbons
2.Nematodes are non-segmented worms that are present in a variety of habitats. Many are free-living (such as those that live in the soil), while others are parasitic and must attach themselves to a plant, insect, animal or human host to survive and reproduce. Some common nematodes include roundworms, Ascaris, hookworms and Trichinella. There are a number of characteristics shared by members of this large phylum.
3.main characteristic of arthropods:hard outer body covering called an exoskeleton,Specialized mouth part,Jointed legs,Compound Eyes,Segmented body
4.chordates have following characteristic Notochord, or a rod of vacuolated cells, encased by a firm sheath that lies ventral to the neural tube in vertebrate embryos and some adults,Hollow nerve cord that lies dorsal to the notochord,Pharyngeal pouches,Endostyle - elongated groove in the pharynx floor of protochordates that may develop as the thyroid gland in chordates