Invertebrates (AIPMT)

Cliona contains siliceous and monoaxon spicules.

Alternation of generation is observed in Adamsia (coelenterate). Reproduction is asexual in polyp and sexual in medusa stages.

Coelenteron is septate in Carybdea.

Tentacles bear colloblasts in Cestus sps.

Convulata has rod-like structures in the cells of the epidermis called rhabdites.

Its body cavity is lined by nucleated peritoneum.

Calanoida is a copepod and larvae of copepods bear naupliar eye. It is an unpaired median eye.

Obelia is diploblastic and has radial symmetry.

Phasmids are absent in anticoma.

In Leucosolenia, asconoid type of canal system is found. In this, the water current reaches the spongocoel after passing through the ostia and goes out through the osculum.

Goalith birdeater has a maximum lifespan of all the invertebrates given here. Its lifespan is 15-25 years.

Crab has antennal glands for excretion. These glands are located in the head.

Masticatory apparatus called Aristotle lantern is present in sea urchins. It consists of 5 strong and sharp teeth.

Water bear is a tardigrade. It is a water-dwelling, eight-legged and segmented micro-animal. It can survive in extreme conditions and thus, is known as the toughest organism.

Mayfly has parabolic superposition compound eye type. In parabolic superposition compound eye type, the parabolic surfaces of the inside of each facet focus light from a reflector to a sensor array.