Correct Answer - Option 3 : Excretion
Explanation-
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Excretion is the process by which the body removes unnecessary compounds from the body using excretory organs.
- Organisms use different organs to remove excreta.
- Specialized cells called flame cells help in osmoregulation and excretion in Platyhelminthes.
Thereby flame cells are concerned with excretion.
Different organisms use different types of organs to remove excreta.
- Unicellular Animals / Amoeba – Diffusion through the surface of the body.
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Platyhelminthes/ Flatworms – Flame cells
- Roundworms/Earthworms – Nephridia
- Arthropods/ Cockroaches – Malpighian tubules
- Crustaceans / Prawns – Antennal glands / Green Glands
- Vertebrates – Kidney
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Excretion is the process of removal of nitrogenous wastes from the body of an organism.
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Nitrogenous waste can be divided into three groups based on its toxicity.
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Ammonia – animals secreting ammonia are called Ammoneotelic
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Urea - animals secreting Urea are called Ureotelic
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Uric acid - animals secreting Uric acid are called Uricotelic
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Excretion is performed by a specialized group of cells or organs called excretory organs.
| Ammonia |
Urea
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Uric Acid
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Highly toxic
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Moderate toxic
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Not very toxic
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Highly soluble
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Moderately soluble
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Very less soluble
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Excreted mainly by aquatic invertebrates, Osteichthyes(bony fishes and tadpole)
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Excreted by Chondrichthyes (Sharks and rays), terrestrial amphibians, and mammals
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Excreted by insects, reptiles, and all birds
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