Radial symmetry is not found in adults of phylum: [2023]
Coelenterata
Echinodermata
Ctenophora
Hemichordata
(4)
Adults of hemichordates have bilateral symmetry.
Consider the following features: [2019]
(A) Organ system level of organisation
(B) Bilateral symmetry
(C) True coelomates with segmentation of body
Select the correct option of animal groups which possess all the above characteristics:
Annelida, Mollusca and Chordata
Annelida, Arthropoda and Chordata
Annelida, Arthropoda and Mollusca
Arthropoda, Mollusca and Chordata
(2)
Mollusca shows organ system level of organisation with unsegmented body (except Neopilina, which is a segmented mollusc), having distinct head, muscular foot, and visceral hump. They usually show bilateral symmetry, but some molluscs (example: Pila) become asymmetrical due to torsion.
Which of the following animals are true coelomates with bilateral symmetry? [2019]
Adult Echinoderms
Aschelminthes
Platyhelminthes
Annelids
While trying to find out the characteristic of a newly found animal, a researcher did the histology of adult animal and observed a cavity with presence of mesodermal tissue towards the body wall but no mesodermal tissue was observed towards the alimentary canal. What could be the possible coelome of that animal? [2025]
Acoelomate
Pseudocoelomate
Schizocoelomate
Spongocoelomate
(2)
In pseudocoelomates, the body cavity is not entirely lined with mesoderm, instead, mesodermal tissue is present along the body wall but not towards the gut.
• Schizocoelomates are animals whose coelom or body cavity develops middle from a split in the mesoderm, the middle germ layer of the embryo.
• In acoelomates, coelom is absent.
Spongocoel is a central cavity found in Sponges.
