Question

An important characteristic that Hemichordates share with Chordates is
A) Pharynx without gill slits
B) Absence of notochord
C) Ventral tubular nerve cord
D) Pharynx with gill slits

Answer 1

Hint: Hemichordates and chordates are different phylums and have some advanced characteristics as they move up in the phylum. Pharyngeal gill slits are present in both phylum invertebrates in chordates and hemichordata.

Complete step by step answer:
-The animalia has two phylums, hemichordata and chordate. The chordate involves invertebrates and vertebrates. The invertebrates have notochord in tail or larval stage.
-Pharynx with gill slits include segments which act as filters that remove water that has entered during the feeding of the organisms in aquatic animals. This allows the organisms to take food material only into the body and no water inside.
-They are repeated openings of mouth throughout the pharynx which help in filtering out the food . They also helped in respiration of aquatic chordates.
-The notochord is present in both phylum chordata and hemichordata. The notochord functions as a skeleton unlike nerve cord.
-Ventral tubular nerve cord is the same as vertebrate spinal cord in function. The nerve cord functions as the main central nervous system of invertebrates only.

The correct option is D.

Note:
The chordates also include some invertebrates which do not have notochord but has spinal cord. The pharynx with gill slits is seen in both chordates (vertebrates and invertebrates) and hemichordates.