# BIO 100 ASU Cell Structure Osmosis and Diffusion Lab Report

## Description

~~6. Report the “Ending Average Volume (cubic millimeters)” and the (positive or negative) “Percent Differences” that you observed in the osmosis experiment for each salt solution below. (These should be recorded in data Table 1 from the Lab 4 Procedures step 2b.) (8 points)

a. 0% salt solution:

b. 1.75% salt solution:

c. 3.5% salt solution:

d. 7% salt solution:

 0% salt solution 1.75% salt solution 3.5% salt solution 7% salt solution Beginning average volume (cu mm) 4000 mm3 4000 mm3 4000 mm3 4000 mm3 Average Ending average volume (cu mm) Change in volume (cu mm) [calculate as: ending mm3 – beginning mm3 ] Percent difference in volume (this is a positive or a negative % value) [calculate as: (change in volume/4000 mm3) x 100 ]

~~9. Using the appropriate osmotic terms (hypertonic, hypotonic, or isotonic) describe what would happen to each organism in the following settings:

a. A single-celled freshwater protist is placed into a beaker of salt water. (3 points)

b. A salt-water snail is mistakenly put into a freshwater tank. (3 points)

c. A head of lettuce is placed soaked in a sink of salt water. (3 points)

d. A carrot is soaked a sink of distilled, pure water. (3 points)

~~10. Some gardeners kill slugs by pouring salt on them. Given what you have learned about osmosis, explain why this method is effective. (4 points)

~~11. Report the surface-to-volume area ratio for each cube from Procedure step 3a. (6 points)

a. Cube 1:

b. Cube 2:

c. Cube 3:

~~12. Given your calculations from question #11 (for the cubes from Procedures step 3a), which cube would be most efficient at moving materials into and out of the cube? Briefly explain the answer based on the concepts covered in Lab 4. (4 points)

~~13. How does the rate of diffusion and surface-to-volume ratio limit cell size? Explain how your results from Procedure 3b illustrate this relationship. (5 points)

~~14. Two identically sized and shaped boneless skinless chicken breasts are purchased for dinner. One chicken breast is cut into approximately 1-inch pieces, while the second is left whole. Both will be cooked at the same temperature and in the same manner. Using information learned about surface-to-volume ratios, which will cook faster? Justify your response based on Lab 4 concepts. (5 points)

~~15. Researchers have discovered that desert hares lose heat through their ears to cool themselves. Given this and knowledge of surface area-to-volume ratios taught in lab, propose an explanation as to why hares that live in hot climates (such as the desert) have such long, flattened ears. (5 points)

Application Question

~~16. How might the information gained from this lab pertaining to cell structures and diffusion be useful to you, or how can you apply this knowledge to your everyday life as a non-scientist? The application will be graded according to the rubric below. (20 points)