Tube feet are extensions of the water vascular system. In sea stars, they help in locomotion, attachment, feeding, and manipulating prey. This MCQ belongs to the Echinodermata topic in Animal Diversity-I and is written to test concept understanding rather than memorized wording.
Many cephalopods possess an ink sac that releases ink as a defensive mechanism. It can confuse predators while the animal escapes by jet propulsion or hiding. This MCQ belongs to the Cephalopoda topic in Animal Diversity-I and is written to test concept understanding rather than memorized wording.
Correct Answer: D. segmentation improves locomotion
Explanation:
Segmentation allows localized muscle contraction and independent movement of body regions. In annelids, it improves burrowing, crawling, and functional specialization along the body. This MCQ belongs to the Annelida topic in Animal Diversity-I and is written to test concept understanding rather than memorized wording.
Insects use a tracheal respiratory system made of tubes opening through spiracles. Oxygen reaches tissues directly, reducing reliance on blood for oxygen transport. This MCQ belongs to the Insecta topic in Animal Diversity-I and is written to test concept understanding rather than memorized wording.
The madreporite is a sieve-like plate that connects the water vascular system with the external seawater. It helps regulate fluid entry into the system. This MCQ belongs to the Echinodermata topic in Animal Diversity-I and is written to test concept understanding rather than memorized wording.
Metamerism is segmentation of the body into repeated units called metameres. It is a major feature of annelids and supports efficient movement and organ specialization. This MCQ belongs to the Annelida topic in Animal Diversity-I and is written to test concept understanding rather than memorized wording.
Correct Answer: D. separate sexes and external fertilization often occur
Explanation:
Many polychaetes have separate sexes and external fertilization, often producing trochophore larvae. This contrasts with many oligochaetes, which are hermaphroditic. This MCQ belongs to the Polychaeta topic in Animal Diversity-I and is written to test concept understanding rather than memorized wording.
Book lungs are respiratory organs found in many arachnids. Their stacked lamellae increase surface area for gas exchange in air. This MCQ belongs to the Arachnida topic in Animal Diversity-I and is written to test concept understanding rather than memorized wording.
Adult echinoderms usually show pentaradial symmetry, commonly arranged in five parts. Their larvae, however, are bilaterally symmetrical. This MCQ belongs to the Echinodermata topic in Animal Diversity-I and is written to test concept understanding rather than memorized wording.
The osculum is the large excurrent opening of a sponge. Water enters through many small ostia, passes through internal chambers, and exits through the osculum. This MCQ belongs to the Porifera topic in Animal Diversity-I and is written to test concept understanding rather than memorized wording.
Cnidarians possess a gastrovascular cavity with one opening. It functions in digestion and distribution of nutrients, but it is not a complete digestive tract. This MCQ belongs to the Cnidaria topic in Animal Diversity-I and is written to test concept understanding rather than memorized wording.
Fasciola hepatica is the liver fluke, a trematode parasite of sheep and other mammals. It has economic importance because it can damage livestock health and productivity. This MCQ belongs to the Trematoda topic in Animal Diversity-I and is written to test concept understanding rather than memorized wording.