Spicules are minute sharp-pointed structures that are typically present in large numbers, like fine particles of ice. Which of the following organisms consists of monoaxon spicules?

Alternation of generation is observed in which of the following?

Coelenteron is a sac like gastrovascular cavity of cnidarians or ctenophores. It is septate in which of the following organisms?

Colloblasts are special cells that are found in the tentacles of some organisms and are used to capture prey. Which of the following organisms has colloblasts?

In certain organisms, rhabdites are rod-like structures in the cells of the epidermis or underlying parenchyma. Which of the following organisms has rhabdites?

The body-cavity of which of the following organisms is lined by nucleated peritoneum?

Naupliar eye is found in the larva of which of the following?

Which of the following tissue-grade organisms is diploblastic and has radial symmetry?

Phasmid refers to a pair of unicellular caudal sensory pouches found in nematodes. They are not found in which of the following organisms?

Most sponges can be classified on the basis of their canal systems. Which of the following types of canal system is present in Leucosolenia?

Which of the following invertebrates has the maximum life span?

Which of the following arthropods has antennal glands for excretion?

Which of the following organisms has a masticatory apparatus called Aristotle lantern for biting the food?

Water bear has been designated as the world's toughest animal. It is a/an

Superposition eyes are found in some arthropods. Which of the following arthropods consists of parabolic superposition eyes?