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Can You Define The General Characteristics Of Animals Belong To The Phylum Arthropoda?

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Shumaela Rana Profile
Shumaela Rana answered
Jointed legs are present on their body and thus they are named as arthropoda (arthro means jointed and poda means foot). These animals have versatile habitat and are found in air, water and on land. The bodies of these animals are also segmented but these segments are external. Their bodies are covered with the hard shell made up of chitin, forming and exoskeleton.

Common examples are prawn, crab, spider, scorpion, centipede, millipede and insects. One third of this phylum consists of insects. Their bodies externally divided into three segments head, thorax and abdomen. In addition three pairs of legs and two pairs of wings are also present; which help them in flying. Two prominent antennas are present on head. Examples are butterflies, house fly, mosquito, grass hopper etc. Some arthropods posses four pairs of legs on their body as spider, scorpion etc. Some arthropods are worms with elongated body. Their bodies are divided into many segments.

Each segment has one or two pairs of legs for example millipede, centipede. Arthropods pass through various stages of development before they reach their adult stage by the process of metamorphosis. This process is of two types; (I) Complete Metamorphosis (ii) incomplete metamorphosis. Complete metamorphosis is the process can be observed in the life cycle of house fly, mosquito, butterfly etc. There are three stages of incomplete metamorphosis and these are egg, nymph and adult animal.
saima jabeen Profile
saima jabeen answered
Arthropods are multicellular, triploblastic, bilaterally symmetrical, metamerically segmented, schizocoelous, protostomous invertebrate metazoans.

Cephalization of some anterior segments of the arthropods from the head is present.
Externally the body is covered with a thick tough, non living, chitinous and protective cuticle, forming the exoskeleton. Exoskeleton is non-living and cannot grow. Appendages are segmental, paired, lateral and jointed and variously modified as jaws, gills and legs etc.
Arthropods are triploblastic animals have true coelom.

Arthropods possess separate striated muscles. More than one pair of jaw is present.
Circulatory system is open, capillaries are absent and arteries open into irregular spaces called sinuses. Malpigian tubules or coelomoducts are the excretory organs that excrete ammonia, urates, amines or guanine. Nervous system is of anneidian type. Compound eye with mosaic vision is well developed. Cilia and flagella are entirely absent.

Sexes are usually separate (dioecious), but a few are hermaphrodite. Sexual dimorphism is usually evident. Parthenogenesis is common in some groups. Gonads and their ducts usually paired. Fertilization is internal and development include complete, incomplete or no metamorphosis. Parental care often well marked.

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