In Hydra waste material of food digestion and nitrogenous waste material are removed respectively from:

Correct answer: C. Mouth and body wall

  • A. Mouth and mouth
  • B. Body wall and body wall
  • C. Mouth and body wall
  • D. Mouth and tentacles

Explanation

In Hydra, indigestible residues are egested through the mouth as there is no anus. Egestion occurs by a sudden squirt due to muscular contraction of body, so that the debris is thrown at a distance. Hydra has neither blood or blood vessels, nor organs of excretion. Due to thinness of the body wall and circulation of water in gastrovascular cavity, most cells of the body remain freely exposed to the surrounding water. Therefore, excretion of waste nitrogenous matter (chiefly ammonia) occurs directly by diffusion through cell membranes in the outside world.

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About Kingdom Animalia

Animals are multicellular, heterotrophic eukaryotes whose cells lack cell walls and chloroplasts, with specialised tissues in most groups. Coverage includes body symmetry, tissue layers, coelom, segmentation and levels of organisation, plus major phyla such as Porifera, Cnidaria, Platyhelminthes, Annelida, Arthropoda, Mollusca and Chordata.

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