Answers

2015-12-19T07:08:00+05:30
Hydra /ˈhaɪdrə/ is a genus of small, fresh-water animals of the phylum Cnidaria and class Hydrozoa, native to the temperate and tropical regions. Biologists are especially interested in Hydra because of their regenerative ability -- they appear .Sponges are animals of the phylum Porifera (/pɒˈrɪfərə/; meaning "pore bearer"). They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through them, consisting of jelly-like mesohyl sandwiched between two thin layers of cells.ot to age or die of old age.

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2015-12-20T12:48:52+05:30
Spicules , Osculum , Internal water circulatory system.
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