Question

Choose the correct match

| Urochordata| Hemichordata | Cephalochordata
---|---|---|---
1.| Chordata| Chordata| Non Chordata
2.| Marine| Fresh water| Fresh water
3.| Notochord in larva| Ciliary feeder| Ciliary feeder
4.| Closed circulatory| Open circulatory| Closed circulatory

A. 1
B. 2
C. 3
D. 4

Answer 1

The phylum chordata includes a large group of different animals. Different characteristics such as notochord, spinal cord hollow tubular nerves, and pharyngeal gill slits unite these different animals under the same type. Hemichordata provides an overview of the relationship between chordates and non chordates.

Complete answer:
Like many other types, the taxonomic division of the Phylum Chordata is a problem. Opinions differ on this particular aspect. The systematic status of half-chord data has long been controversial. In recent years, the half chord dates have been separated from the Phylum Chordata and assigned a separate phylum.

Hemichordata:
They are bilaterally symmetrical deuterostome animals. The circulatory system is simple and well developed; closed type; usually with contractile vesicles and two longitudinal vessels, one dorsal and one ventral, connected by the lateral vessels and sinuses. Elimination via a single glomerulus in the proboscis. The primitive nervous system, consisting mainly of the intraepidermal nerve plexus. . The sexes are separate or united. External fertilization. Development is mostly indirect through free-floating tornaria larvae. Direct development can also be found. It includes exclusively marine animals. The members of this phylum are ciliary feeders.

Chordata :
The phylum chordata includes a large group of different animals, from ascidians to humans. Different characteristics such as notochord, spinal cord hollow tubular nerves, and pharyngeal gill slits unite these different animals under the same type.
Division of Chordata:
• Subphylum Cephalochordata
• Subphylum Urochordata
• Subphylum Vertebrata (Craniata)

Urochordata:
This subtype is also known as a tunicate because an adult's body is caught in a skin test or tunic made from an organic substance called cellulose called tunicin. The notochord exists only in the tail of the larva and disappears as an adult. The dorsal tubular nerve cord is located inside the larva. It is replaced by the dorsal ganglion in adults. Urochordates have an open circulatory system.

Cephalochordata:
Both adults and larvae are motile. The notochord extends to the front end of the body. The notochord is preserved throughout life. More and better developed pharyngeal gill slits. Atria are also present. The tail exists throughout life. Cephalochordates have a closed circulatory system . . The members of this phylum are ciliary feeders

Hence, the correct answer is option (C).

Additional information:
Hemichordates have long been considered the lowest group of Chordata that make up the notochord, nerve cord, and pharyngeal gill slits, the main feature of the phylum chordata. Modern workers claim that the notochord of the half-chord data is not an actual notochord, and that the central nervous system, which contains longitudinal ventral nerve chains, exhibits characteristics of the major invertebrate phyla.
In Urochordates larva shows retrogressive metamorphosis .

Note: Let’s summarise all the point above to answer the given question
Urochordata: Chordate, Marine, Notochord is present only in larval tail, Open circulatory system
Cephalochordata: Chordate, Marine, Ciliary feeder, ,Closed circulatory system
Hemichordate: Non-chordate, Marine, Ciliary feeder, Open circulatory system