Question

Blastopore develops into the anus in

• A. protostomes
• B. deuterostomes
• C. pseudocoelomates
• D. acoelomates

Answer 1

The correct option is B deuterostomes

The opening of the archenteron in the gastrula stage of embryo is called the blastopore.

In Protostomes, blastopore develops into the mouth. Anus develops later. As the mouth is formed first, these animals are called protostomes. ‘Proto’ means first and ‘stoma’ means mouth. Protostomes include annelids, arthropods and molluscs.

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.