Question

Maximum diversity is found in which of the following phylum?
a. Chordata
b. Arthropoda
c. Protozoa
d. Annelida

Answer 1

Hint: Phylum (animals) is a principal taxonomic category that ranks above the class and below kingdom and it is equivalent to the division in plants. They can be cockroach, butterfly, spider, centipede, millipede etc.

Complete answer: Maximum diversity is found in the phylum Arthropoda. It is the largest animal kingdom with about 9,00,000 species. This phylum is heterogeneous group including a variety of animals differing in structure, habitat and feeding habits.

General Characteristic features of Arthropoda:
- These animals live in a variety of habitats such as oceans (Limulus), fresh water (Daphnia), land (cockroach, locust) and air (Housefly and mosquito).
- Arthropods are the bilaterally symmetrical animals.
- These animals possess organ system level of organization.
- They are the triploblastic animals.
- The body of arthropods is segmented.
- Arthropods are the coelomates/true coelomic animals.
- The digestive tract is complete and has glands and digestion of food is extracellular.
- Respiration through various types of respiratory structures such as gills (prawns and crabs), book lungs (scorpion and spiders), tracheal system (butterfly, cockroach and mosquito).
- The circulatory system is of open type.
- Arthropods are mostly dioecious animals. Males and females have separate sexes.

Hence, the correct answer is option (B).

Note: There is a presence of chitinous exoskeleton in the arthropods and this exoskeleton is shed at regular intervals. The process of shedding of exoskeleton is called ecdysis or moulting. This shedding promotes growth and provides space for the growing organs.