LAB 4
LAB 4
1. Answer the following questions:
a. List four cell structures that are common to both plant and animal cells. (4 points)
b. What structures are unique to plant cells? (2 points)
c. What structures are unique to animal cells? (2 points)
2. List five structures observed in the cell images and provide the function of each structure. (5 points)
A. Structure 1 and function
B. Structure 2 and function
C. Structure 3 and function
D. Structure 4 and function
E. Structure 5 and function
3. William is observing a single-celled organism under a microscope and notices that it has a nucleus and is covered in small, hair-like structures.
A. Provide a probable name for this organism (1 point)
B. Explain why William came to this conclusion. (2 points)
4. Where in the cell are the chloroplasts located? (5 points)
5. In the Spirogyra cells observed on the virtual microscope, about how many circular green chloroplasts were seen in a single cell at 40X magnification? (2 points)
6. What were the percent differences between the volumes of the potatoes in the osmosis experiment for each salt solution? (8 points)
a. 0%
b. 1.75%
c. 3.5%
d. 7%
7. What extraneous variables might have affected how the results came out in the osmosis experiment? Describe three. (6 points)
8. In osmosis, which direction does water move with respect to solute concentration? (2 points)
9. Answer the following questions:
a. Explain what would happen to a freshwater unicellular organism if it were suddenly released into a saltwater environment. Use the terms isotonic, hypotonic and hypertonic in the answer. (3 points)
b. What would happen if a marine organism were placed in freshwater? (3 points)
10. A student purchases and weighs 5 pounds of carrots from a local grocery store. She notices that the grocery store constantly sprays its produce with distilled water. After returning home, she weighs the carrots again and discovers that they weigh only 4.2 lbs. They also no longer seem as crisp and taut. Provide a possible explanation for why the carrots weighed more at the store, based on the information learned in this lab. (5 points)
11. People always say that leeches can be removed from the body by pouring salt on them. Based on what the student learned about osmosis, provide an explanation that supports or refutes this information. (5 points)
12. What is the rate of diffusion for the potato cubes from the surface-to-volume experiment (procedure 3b)? (6 points)
A. Cube 1
B. Cube 2
C. Cube 3
13. Assume the potato cubes are cells. Which cube would be most efficient at moving materials into and out of the cube? Briefly explain the answer. (4 points)
14. From what was observed in the potato procedure, how do the rate of diffusion and surface-to-volume ratio limit cell size? (5 points)
15. One night, Hans decides to cook a hamburger and spaghetti with meatballs. To test ideas of surface-to-volume ratios, he makes a quarter pound hamburger and a quarter pound meatball and cooks them at the same temperature. Which food item will cook the fastest and why? (5 points)
16. While watching a special on animals, Brianna discovers that hares tend to lose heat through their ears. Based on this and what is known about surface-to-volume ratios, propose an explanation as to why hares that live in hot climates (such as the desert) have large, extended ears. (5 points)
17. (Application) How might the information gained from this lab pertaining to cell structures and diffusion be useful to a student employed in a healthcare related profession? (20 points)