Question

The connecting link between chordates and non-chordates is
A. Peripatus
B. Balanoglossus
C. Sphenodon
D. Tachyglossus

Answer 1

The connecting connection is defined by an organism that has two community characteristics. As an intermediate organism between two classes, it will function. It is used by a single organism to study the characteristics of both types.

Complete answer: The connecting link between chordates and non-chordates is Balanoglossus. Since the properties of the notochord and pharyngeal are found in Balanoglossus. Chordates have certain characteristics that are normal. The dorsal heart is located in non-chordates. A dorsal heart is also borne by Balanoglossus. That's the reason why both chordates, as well as non-chordates, have certain features of Balanoglossus. This is the reason why it is the connecting link between chordates and non-chordates. Connecting links between two groups include Peripatus-Annelida and Arthropoda, Sphenodon-Amphibian and Reptiles, Tachyglossus-Reptiles and Mammals, Balanoglossus-Chordates and Non-Chordates, Sphenodon-amphibian and reptiles. The connecting link between the amphibians and reptiles is Sphenodon. The connecting element between reptiles and mammals is Tachyglossus.
Hence, option B is the right answer.

Additional information: Difference between chordates and non-chordates:
i. Chordates are warm-blooded, whereas, non-chordates are cold-blooded.
ii. Chordates respire through lungs or gills, whereas, non-chordates respire through body surface or gills.
iii. Haemoglobin is present in chordates, while non-chordates have hemolymph.
iv. Chordates have a closed circulatory system, whereas, non-chordates have an open system.

Note: Balanoglossus is an ocean-dwelling worm. It is a deuterostome that resembles Ascidians or sea squirts, in that it possesses branchial openings or gill slits. In Balanoglossus, the heart is dorsal, which resembles characteristics of non-chordates.