EVERYDAY SCIENCE

Detailed explanation-1: -In deuterostomes, blastopore develops into the anus and the mouth is formed later. As the mouth is formed as a secondary opening, these animals are called deuterostomes. ‘Deutero’ means secondary and ‘stoma’ means mouth. Deuterostomes include echinoderms, hemichordates and chordates.

Detailed explanation-2: -In protostomes, the site of gastrulation is said to give rise to the mouth, while in deuterostomes it forms the anus with the mouth arising from a second opening distant to the site of gastrulation.

Detailed explanation-3: -Some examples of deuterostomes include vertebrates (and thus humans), sea stars, and crinoids. In deuterostomy, the developing embryo’s first opening (the blastopore) becomes the anus, while the mouth is formed at a different site later on.

Detailed explanation-4: -In Deuterostomes (“mouth second”), the mouth develops at the other end of the gut (Figure 3) and the anus develops at the site of the blastopore. Protostomes include arthropods, mollusks, and annelids. Deuterostomes include more complex animals such as chordates but also some “simple” animals such as echinoderms.

Detailed explanation-5: -Deuterostomes are animals in which the anus develops before the mouth during the embryonic stage. Most deuterostomes have radial and regulative (no predetermined functions) cleavage, and enterocoely formation of the coelom.