Question

which one is correctly matched?
(a) Scorpion, Spider, Cockroach-Ventral solid central nervous system.
(b) Cockroach, Locust, Taenia-metameric segmentation.
(c) Liver Fluke-Bilateral symmetry.
(d) Centipede, Prawn, Sea Urchin-Jointed appendages.

Answer 1

Hint: In the above-mentioned groups more than one option is correct. It includes the group that is associated with the nervous system and the other one is associated with body design.

Complete answer:
In the above-mentioned options two of them are correctly matched, they are Scorpion, Spider, Cockroach-Ventral solid central nervous system, and Liver Fluke-Bilateral symmetry.
-The first group includes three animals of the same phylum Arthropoda. These are a Scorpion, Spider, and Cockroach having a ventral solid central nervous system. In this group, both Spiders and Scorpion belong to class-Arachnida but Cockroach belongs to the class Insecta. In invertebrates, the ventral nerve cord is the structure of their central nervous system. Its function is equivalent to the function of the spinal cord vertebrate animals.
-The second group includes Cockroach, Locust, and Taenia. The Cockroach and Locust belong to the phylum Arthropoda and they are having metameric segmentation whereas Taenia is a flatworm, having an unsegmented body. Metameric segmentation is the division of an animal's body excluding the head region. The whole body is divided into several segments each containing the same organs.
-Liver fluke is a flatworm and it has bilateral symmetry.
-In the fourth group, the Centipede and the Prawn belong to the phylum Arthropoda so they bear the jointed appendages, but the Sea Urchin belongs to the phylum Echinodermata, so it has tube feet for locomotion, not the jointed appendages.
So, the correct answer is, 'Scorpion, Spider, Cockroach- ventral solid central nervous system' and also 'Liver Fluke-Bilateral symmetry'.

Note: -The function of the ventral nerve cord in invertebrate animals is similar to the function of the spinal cord of the vertebrate animals.
-Metameric segmentation is most commonly found in Annelid worms (e.g. earthworms). In Arthropods and the embryonic development of all vertebrates., the metameric segmentation occurs internally.