biology exaamination on earthworms . correct answers. 2021.

1.Approximately how many segments did the whole earthworm have? 96 2. What is the function of the clitellum, the only organ visible externally on earthworms? 3. It secretes mucus that is important in reproduction The ...

1.Approximately how many segments did the whole earthworm have? 96 2. What is the function of the clitellum, the only organ visible externally on earthworms? 3. It secretes mucus that is important in reproduction The worm alternates between extension and pulling the rest of its body after the extension. It extends the front of its body by contracting its circular muscles making itself _long and thin__. It pulls the rest of its body by contracting its longitudinal muscles, making itself Short and fat. 4. What extends when the front of the earthworm extends and guides the direction in which the earthworm moves? The prostomium 5. How did the earthworm's mode of location compare to the nematode's mode of location? The earthworm contracted and extended, where as nematode moves side to side 6. Which of the following is a correctly labeled image of an earthworm's internal anatomy in cross section? 7. Which of the following is a correctly labeled image of an earthworm's musculoskeletal system in cross section? 8. What feature of the intestine increases its surface area, and hence, an earthworm's ability to absorb nutrients? The typhlosole, an internal fold in the intestine 9. What is the function of the organ outlined in the picture? Excretion of waste 10. Which of an earthworm’s features is highlighted in the picture? 11. On what side of an earthworm are the setae located and how does that location connect to their function? Ventral, because they provide traction during locomotion so they need to be underneath the worm 12. Which of the following is a correctly labeled image of an earthworm’s internal anatomy in longtudinal anterior section? 13. Which of the following is a correctly labeled image of an earthworm’s internal anatomy in longitudinal section? 14. Does the fact that you were only able to identify seminal vesicles in the earthworm longitudinal section slide indicate that the earthworm you examined is male? Why or why not? No earthworms produce eggs and sperm, the ovaries are just too small to see 15. Which of the following is a correctly labeled image of an earthworm’s digestive system in a longitudinal section? 16. Why does the gizzard have more musculature than the crop? The gizzard macerates and crushes food. The crop mostly stores food 17. What are the structures shown in this picture? Septa 18. The dorsal side of an earthworm is muddy brown in color and darker than the ventral side. How might such coloring benefit the organism in its natural habitat? It acts as camo. Blend with dirt. Ventral side hidden 19. Although earthworms do not have large appendages to display bilateral symmetry like right and left arms, they do have a bilateral plan. This is easiest to visualize if you examine the earthworm cross section diagram in the media player and observe the bilateral symmetry of the interior organs. In what direction does the axis of symmetry run (think of what type of sectioning of the animal will leave mirror-image halves)? The axis of symmetry is anteroposterior 20. Which of the following earthworm internal features is appropriately assigned as dorsal or ventral? Ventral nerve cord, dorsal blood vessel 21. Which organ in an earthworm pumps blood? Aortic arches 22. Which is the closest an earthworm has to sensory organs like ears or a nose? Light 23. Why were respiratory organs, similar to lungs or gills, not seen on any of the earthworm slides? Earthworms have no respiratory systems. They absorb oxygen through skin In experiment 1, what was the main type of epithelial tissue you observed in the dermis and epidermis image? Scarified squamous What type of epithelial tissue is pictured below? Simple Column