Chapter 27 HW - Biology Honors Prentice Hall Textbook by...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Biology Honors Prentice Hall Textbook by Miller/Levine Chapter 27 HW Period 2 3/5/10 1. D 2. B 3. B 4. C 5. B 6. B 7. C 8. A 9. B 10. C 11. Coelomates contain a coelom, which is a fluid filled body cavity which is lines with tissue derived from the mesoderm. Acoelomates do not contain a coelom. 12. Flat worms do not use a circulatory system, and instead rely on diffusion to transport oxygen and nutrients to their internal tissues, and to remove carbon dioxide and other wastes. They have no gills or respiratory organs. They have flame cells which function in excretion by removing excess water from the body, and they are joined together to form a network of tubes that empties into the outside environment through tiny pores. 13. Planarians feed on recently dead animals, and they have a digestive cavity with a single opening a mouth, through which food and waste pass. They extend the pharynx out of the mouth, and it then pumps food into the digestive cavity or gut. Once inside, food is digested by cells of the gut where digestion and nutrient absorption takes place. Digested food finally diffuses from the digestive cavity into all other body tissues. 14. Flat worms have eye spots, to detect the amount of light available. According to the amount of light in their environment, they move around. Also, they have specialized cells to detect external stimuli, such as chemical found in food or the direction in which water is flowing. 15. The Schistosoma fluke causes schistomiasis in humans, and the Schistosoma eggs clog blood vessels, causing swelling and tissue decay in the lungs, liver, spleen, or intestines. To help stop thi s fluke from affecting humans, tropical areas should improve their sewage systems. 16. Tapeworms have no digestive tract, so they can just absorb food through their cell walls.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 01/02/2012 for the course BIO 101 taught by Professor Dr.chan during the Fall '11 term at Marine Biological Laboratory.

Page1 / 3

Chapter 27 HW - Biology Honors Prentice Hall Textbook by...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online