Question

17) Where is the pharyns on the Planariad? 18) Could you identify the extended pharynx? What did it look like? What purpose does it serve? 19) Using the lowest power on the compound microscope, observe the prepared slide of a whole Planaria. Label the following on the mouth, ventral nerve cord drawing below: cerebral ganglion, eyespot, gut, pharyns, 20) Examine the Planaria body for possible digestive tract openings. How many openings to the digestive tract are present? 21) Using the compound microscope, observe the prepared slide of a cross-section of a Planaria. draw and label: eiliated epidermis, gut, gut lining, pharynx 22) What kind of body cavity do you find in Planaria: acoelomate, eucoelomate, or pscudocoelomate? 23) How do you think the body of a Planaria is supported?
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Answer 1

17. Pharynx on the Planaria is located on the underside of the worm halfway down towards the tail.

18. Yes the extended Pharynx can be identified. The extended Pharynx is looks like a straw or a tube. The planarian eats by using its long, highly muscular pharynx. This protrudes through the mouth in the presence of food. The tip is placed against the food and soft or disintegrating particles of tissue are sucked up into the main gastrovascular cavity by the muscles in the pharynx.

20. Planaria have a single-opening digestive system (incomplete) with branches that transport nutrients to all parts of the body

22. The Planaria have an acoelomate body cavity. Space, where a body cavity would be present, is taken up by 3 layers of skin (ectoderm, mesoderm, endoderm). The space the mesoderm takes up leaves no room for a body cavity

23. The body of Planaria is supported by Hydrostatic skeleton

Mouth Que 19. Ventral nerve cord Gut Pharynx Eye Spot Cerebral Ganglion 0 Que 21. Cilia ut umen Ventral