which group of animals belong to the
phylum
Authwboda, bered on the characteristics
features like jointed
affendages & exoskeleton and bi or
tri segmented sody?
Answers
Explanation:
On a pleasant evening, you decide to go to a park. However, you end up having painful itchy eruptions on the skin. Clearly, you were bitten by an insect. After all, insects are everywhere. They belong to a group of animals called the Phylum Arthropoda, which form the largest percentage of the world’s organisms. They make up about 80 percent of the known species of animals! It is quite hard to escape them.
Answer:
→ Phylum arthropoda contains invertebrates with jointed appendages. ( Arthros - joint, poda - foot or appendage)
→ It is the largest phylum in Kingdom Animalia with over 90000 species.
→ These animals inhabit a variety of habitat and are cosmopolitan.
→ They posess a true coelom and has a blood filled cavity called as haemocoel.
→ They are bilaterally symmetrical and triploblastic.
→ Their body is divided into head, thorax and abdomen.
→ Their body is metamerically segmented.
→ Digestive system has specialised structures such as crop or gizzard or protrusible pharynx.
→ The circulating blood is called as haemolymph and the respiratory pigment is erythrocruorin.
→ Gaseous exchange is through special structures such as gills, book lungs, book gills and trachea.
→ Excretion is through green glands or coxal glands. Nephrida is absent in these organisms.
→ They have a double ventral nerve cord with a dorsal nerve ring.
→ They have sensory organs like antennae, simple and compund eyes, sensory hairs, statocysts etc.
→ Fertlization is internal and the organisms are dioecius. Development may be direct or indirect.
→ The subphylums of these class are:
- Trilobitomorpha: This is an extinct class. They were mostly marine animals. Example: Dalmanites, Triarthus
- Chelicerata: It includes the class Merostomata and Arachnida. Some examples are : Limulus, Spider etc
- Onychophora: This includes the terrestrial, primitive worm like organisms. Example:Peripatus
- Mandibulata: This includes the classes Crustacea, Chilopoda, Diplopoda, Pauropoda, Symphylla, Insecta. Some of the examples are Daphnia, Cypris, Grasshopper, Julus, Scutigerella etc.