Question

COMPLETE ALL THE TABLE

Table 21.1 Summary of Ecdysozoan Characteristics Nematoda Chelicerata Arthropoda Crustacea Hexapoda Symmetry? Cuticle composition? Skeletal system type? Any ciliated cells? Terminal mouth? Segmented Appendages? Muscle in gut? Locomotion mode? Type digestive system? Type circulatory system? Heart present? Type respiratory system? Describe nervous system Describe excretory system Describe body plan Unique features?

Answer 1

Ecdysozoan Characteristics

	Nematoda	Chelicerata	Arthropoda Crustacea	Hexapoda
Symmetry	Head of a nematode exhibits radial symmetry while the body is bilaterally symmetrical while cut (lengthwise) in half it will produce mirror image of the other half of the body	Chelicerata exhibit bilateral symmetry as explained for nematodes.	Crustaceans also exhibit bilateral symmetry	Bilateral symmetry is exhibited in hexapoda
Cuticle Composition	Cuticle in nematode is made of collagen like proteins.	Cuticle is made of chitin and other hardened protein	Cuticle is made of chitin and calcium carbonate makes it more hardened and is called a shell in certain organisms.	Cuticle in hexapoda is chitinous in the procuticle layer with proteins and other substances while the epicuticle is a thin waxy water resistant layer, which lacks chitin.
Skeletal system type	The cuticle covering provides the definite shape for these organisms acting as the exoskeleton. The fluid filled spaces inside the body provide a hydrostatic skeleton to support the muscles.	Exoskeleton made of the thick covering of the cuticle.	Exoskeleton is hard and gives definite shape and support to the organisms	Exoskeleton helps to maintain the shape and structural support.
Any ciliated cells?	Sensory neuron is a ciliated cell in nematodes, but they are not motile.	No ciliated cells	Ciliated cells present. For eg. Chordotonal organs	Ciliated cells present. For eg. Chordotonal organs