Spongin is a fibrous protein that forms a flexible skeleton in some sponges. It differs from hard mineral spicules and gives certain sponges an elastic texture. This MCQ belongs to the Porifera topic in Animal Diversity-I and is written to test concept understanding rather than memorized wording.
Metagenesis is alternation of generations between polyp and medusa phases in some cnidarians. Obelia is a standard example used to explain this life-cycle pattern. This MCQ belongs to the Cnidaria topic in Animal Diversity-I and is written to test concept understanding rather than memorized wording.
Proglottids are repeated segments of a tapeworm containing reproductive organs. Mature and gravid proglottids help produce and release large numbers of eggs. This MCQ belongs to the Platyhelminthes topic in Animal Diversity-I and is written to test concept understanding rather than memorized wording.
Nematodes mainly have longitudinal muscles and lack circular muscles. Their movement is a whip-like thrashing produced against the elastic cuticle and pseudocoelomic fluid. This MCQ belongs to the Nematoda topic in Animal Diversity-I and is written to test concept understanding rather than memorized wording.
Most bivalves are filter feeders. Their gills function in both gas exchange and food collection, while the radula is absent. This MCQ belongs to the Bivalvia topic in Animal Diversity-I and is written to test concept understanding rather than memorized wording.
Sponges show cellular level organization. Their cells perform specialized functions, but they are not organized into true tissues, organs, or organ systems. This MCQ belongs to the Porifera topic in Animal Diversity-I and is written to test concept understanding rather than memorized wording.
Cnidarians are diploblastic animals because they develop from two germ layers. The mesoglea lies between epidermis and gastrodermis but is not a true mesodermal layer. This MCQ belongs to the Cnidaria topic in Animal Diversity-I and is written to test concept understanding rather than memorized wording.
Many flatworms, especially parasitic forms like tapeworms, are hermaphroditic. This increases reproductive success when mates are limited inside a host. This MCQ belongs to the Platyhelminthes topic in Animal Diversity-I and is written to test concept understanding rather than memorized wording.
Rotifers possess a corona, a ciliated crown that helps in locomotion and feeding. The beating cilia may appear like rotating wheels under the microscope. This MCQ belongs to the Rotifera topic in Animal Diversity-I and is written to test concept understanding rather than memorized wording.
Entamoeba histolytica causes amoebiasis or amoebic dysentery. The parasite invades the intestinal wall and may produce ulcers, abdominal pain, and blood or mucus in stool. This MCQ belongs to the Entamoeba histolytica topic in Animal Diversity-I and is written to test concept understanding rather than memorized wording.
Gemmules are resistant internal buds produced by many freshwater sponges. They allow survival during harsh conditions and can develop into new sponges when conditions improve. This MCQ belongs to the Porifera topic in Animal Diversity-I and is written to test concept understanding rather than memorized wording.
Cnidarians have a nerve net, a diffuse nervous arrangement suitable for radial animals. It coordinates simple movements and responses without forming a centralized brain. This MCQ belongs to the Cnidaria topic in Animal Diversity-I and is written to test concept understanding rather than memorized wording.
