Cell Structure, Osmosis, and Diffusion

30 Jun Cell Structure, Osmosis, and Diffusion

Question Description
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. Below are five structures observed in cells. List the function of each structure. (5 points)

a. Chloroplasts

b. Golgi apparatus

c. Ribosomes

d. Central vacuole

e. Rough endoplasmic reticulum

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)

a.

b.

c.

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 iissottoniicc, hyypottoniicc and hyypeerrttoniicc 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 surface-to-volume ratio and rate of diffusion for each potato cube from Procedure 3b? (6 points)

a. Cube 1 surface-to-volume ratio

b. Cube 1 rate of diffusion

c. Cube 2 surface-to-volume ratio

d. Cube 2 rate of diffusion

e. Cube 3 surface-to-volume ratio

f. Cube 3 rate of diffusion

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. ((Applliiccaattiion)) How might the information gained from this lab pertaining to cell structures and diffusion be

useful to you in your everyday life or to a healthcare professional? (20 points)

Key components of critical thinking and application include the following:

1. Demonstrates application and comprehension of the scientific principles.

2. Displays competence in applying scientific knowledge to your personal or professional life.

3. Relevant content is supported by facts, data, and detailed examples.

4. The application paragraph is organized and structured.

Crriittiiccaall

TThiinkkiingg

aand

Applliiccaattiion

off

IInfforrmaattiion