Tag: phylum hemichordata

Statement 'c' is incorrect because Branchiostoma (Amphioxus) belongs to Cephalochordata, not Hemichordata. Statements a, b, and d are biologically accurate.

The proboscis gland (also known as the glomerulus) in Balanoglossus is the primary excretory organ responsible for filtering waste products.

Hemichordates share significant developmental and anatomical similarities with Echinoderms, particularly in their larval stages (e.g., tornaria larva vs. bipinnaria larva).

Balanoglossus is a ciliary feeder that captures food particles from the water or sediment, which is a form of phagotrophic nutrition.

The velum is a muscular fold found in the pharynx of cephalochordates like Amphioxus (also known as Branchiostoma).

Hemichordates were historically considered a sub-phylum of Chordata, but are now a separate phylum that serves as a link between non-chordate invertebrates and true chordates.

In chordates, the notochord is a flexible, rod-shaped structure that develops during the embryonic stage. It is located dorsally to the alimentary canal and ventrally to the dorsal central nervous system (spinal cord).

The proboscis gland is the primary excretory organ in Balanoglossus. Protonephridia are not the primary excretory structures in adult hemichordates.

Balanoglossus is known to undergo physiological changes during starvation, including the reduction of body size as it metabolizes its own tissues.

A Protochordate belongs to any two invertebrate subphyla of the phylum Chordata- the Tunicates (sea squirts, salps, etc.) and the Cephalochordates (amphioxus). Like the remaining subphylum of the chordates, the Vertebrata, the protochordate has a hollow dorsal nerve cord, gill slits and a stiff supporting rod, the notochord, the forerunner of the backbone. The protochordate differs chiefly from the vertebrates in not having a backbone. Hence, they have bilateral symmetry, coelom, and a circulatory system. However, they lack jointed appendages