Biology - Excretory Products and their Elimination Question with Solution | TestHub
Which of the following statements are correct with respect to excretory system?
A. Proto nephridia are present mostly in animals that lack true body cavity.
B. Sponges have contractile vacuoles which collect and discharge waste products.
C. Ants have set of blind ended tubules called as malpighian tubules.
D. True organs of excretion are found in those animals that show bilateral symmetry.
E. Echinodermata have specialized excretory organs, called as green lands.
Options:
Answer:
Solution:
Statement A is correct. Protonephridia are the primary excretory structures found in organisms such as Platyhelminthes, which are acoelomates lacking a true body cavity.
Statement B is incorrect. Contractile vacuoles are typically found in unicellular protozoans for osmoregulation. Sponges are multicellular organisms that lack specialized excretory organs and eliminate waste primarily through simple diffusion.
Statement C is correct. Ants are insects belonging to the phylum Arthropoda. The excretory system of insects consists of blind-ended structures called Malpighian tubules.
Statement D is correct. True excretory organs, such as protonephridia, nephridia, and kidneys, are a feature of bilaterally symmetrical animals. Asymmetrical animals like sponges and radially symmetrical animals like cnidarians lack true excretory organs.
Statement E is incorrect. Echinoderms do not have a specialized excretory system. Nitrogenous waste is eliminated by diffusion through the tube feet or respiratory tree. Green glands are excretory organs found in crustaceans, not echinoderms.
The correct statements are A, C, and D.
