Tag: animal diversity - i (inverterbrate phyla)

Ctenophore phylum which includes Comb jellies exhibit Biradial symmetry. It is when the organism can be divided up into equal parts, but with two planes only. Hence option C is correct.

Comb jellies are not strong swimmers. They are typically planktonic animals, transparent and unpigmented and most swim by the synchronous beating of the eight rows of comb plates. Hence, option C is correct.

Ctenophora is considered as a small phylum. The phylum contains very few genera and only about 80 species. This group includes a set of marine animals. These organisms are commonly called as comb jellies. Earlier, this phylum was placed under Coelenterata. Hatschek placed it under a separate phylum. 

Biradial symmetry and lack of cnidoblasts are characteristics of phylum Ctenophora. They have adhesive structure, known as coloblasts instead of cnidoblasts. Both Ctenoplana and Beroe are ctenophores. Hence, option C is correct.

The ctenophores are diploblastic with a biradial symmetry or modified radial  (with an underlying bilateral symmetry), which is a bit different than the radial symmetry typical of cnidarian.

Sea Walnut (Pleurobrachia) belongs to the phylum Ctenophora. These organisms are radially symmetrical, diploblastic, marine, and exhibit bioluminescence.

Boroe is a type of comb jelly and has a body structure that is transparent and sac like with a mouth at one end. The gastrovascular channels are beneath the cilia and the animal lacks any tentacles otherwise. So, the correct answer is 'Boroe.

Comb jellies are oval-shaped animals with eight rows of tiny comb-like plates that they beat to move through the water.  They are gelatinous animals belonging to the phylum of animals that live in marine waters worldwide, ctenophora.
Thus, the correct answer is option D.

Ctenophora, commonly known as comb jellies, is a phylum whose members are exclusively marine and live only in salt water, unlike groups such as Annelida, Arthropoda, and Mollusca which have many terrestrial and freshwater species.

Ctenophores, also called the comb-jellies, exhibit bioluminescence. The enzyme called photoprotein is present in them in which luciferin is combined with oxygen. When the calcium changes the shape of the ptotoprotein, light is given off.