NEET BIOLOGY

Detailed explanation-1: -Notochord is a mesodermally derived rod-like structure formed on the dorsal side during embryonic development in some animals. Animals with notochord are called chordates and those animals which do not form this structure are called non-chordates, e.g., porifera to echinoderms.

Detailed explanation-2: -Non-Chordates are divided into ten phyla. Those phyla are-Protozoa, Porifera, Cnidaria, Platyhelminthes, Aschelminthes, Annelida, Arthropoda, Mollusca, Echinodermata and Hemichordata.

Detailed explanation-3: -Echinoderms are the most closely related phylum to the phylum Chordata, which includes many complex organisms such as humans. Their shared common ancestor was likely a bilaterally symmetrical organism with a cephalized (centralized in a head region) nervous system.

Detailed explanation-4: -Non-chordates are animals without a notochord. The first phylum under non-chordates is Porifera. The members of this phylum are known as sponges. These are primitive, multicellular, asymmetrical, marine animals with cellular level of organisation.

Detailed explanation-5: -Ans. Porifera, Cyonopera, Platyhelminthes, Aschelminthes, Cyonophera, Annelida, Mollusca, Echinodermata, Hemichordata, and Arthropods are examples of non-chordates found in the phylum. Earthworms, flatworms, sponges, jellyfish, cockroaches, and other creatures are among them.