1. Skeleton of sponges is made of spicules or spongin fibres. Spicules are formed of calcium carbonate and silica.

    Skeleton of sponges is made of spicules or spongin fibres. Spicules are formed of calcium carbonate and silica.

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  2. Bilateral symmetry is a type of symmetry found in most animals in which appendages and organs of the body are paired and where the body can be divided into two equal halves by a section passing through midsagittal plane, e.g., Fish, Frog, Rat, Human beings, etc. It is an adaptation of motile life stRead more

    Bilateral symmetry is a type of symmetry found in most animals in which appendages
    and organs of the body are paired and where the body can be divided into two equal halves by a section passing through midsagittal plane, e.g., Fish, Frog, Rat, Human beings, etc. It is an adaptation of motile life style.

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  3. Enterocoelom is a true coelom which develops as lateral pouches from the embryonic gut (archenteron), e.g., Echinodermata and Chordata. This. cavity is lined by cells of mesodermal origin.

    Enterocoelom is a true coelom which develops as lateral pouches from the embryonic gut (archenteron), e.g., Echinodermata and Chordata. This. cavity is lined by cells of mesodermal origin.

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  4. Pseudocoelom is false body cavity which is generally endodermal in origin and not lined by mesoderm.

    Pseudocoelom is false body cavity which is generally endodermal in origin and not lined by mesoderm.

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  5. They are animals having two germinal layers in the embryo, the outer ectoderm and the inner endoderm, e.g., porifera and cnidaria

    They are animals having two germinal layers in the embryo, the outer ectoderm and the inner endoderm, e.g., porifera and cnidaria

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