Anas Zoology

What are Sponges ? Simple, mostly marine animals, adult sponges live permanently attached to rocks, corals, and shipwrecks. A few species live in freshwater. Sponges belong to phylum Porifera. The Porifera vary in size and shape, from thin sheets to huge barrels, but all have the same basic structure: different types of specialist cells, but no organs. A system of water canal branches through the sponge, and water is drawn into them through tiny pores in the sponges surface. Special chambers or cells lining the water canals trap and engulf bacteria from plankton for food, and waste water exits through large openings called oscula.  Many sponges are classically "spongy", others are rock hard, soft, or even slimy depending on the supporting skeleton, which is made of tiny spicules of silica or calcium carbonate. Spicules vary in shape and number between species and can be used in identification. Calcareous Sponges: Lemon sponge is a calcareous sponge. The skeleton of Calcarea i...

Visit You tube channel for more MCQ's:  https://www.youtube.com/channel/UCDI5O7VNvIby-Faq_ptLefw Previous Year Questions: 1. Identify the part of the seed from the given figure which is destined to form root when the seed germinates. (2024) 1) A     2) B 3) C     4) D Ans. 3 - C Explanation: In the given figure 'C' represents radicle. Radicle is the part of the seed from which roots are formed. 2. Which of the following is an example of actinomorphic flower ? (2024) 1)  Datura          2) Cassia 3) Pisum            4) Sesbania Ans. 1 - Datura Explanation: Datura is an example of actinomorphic (radial symmetry) flower. Cassis, Pisum and Sesbania are examples of zygomorphic (bilateral symmetry) flower. 3. Identify the type of flowers based on the position of calyx, corolla and androecium with respect to the ovary from the given figures (a) and (b)  (2024) 1) (a) Epigynous; (b) Hypogynous...