In Class, We Placed A Potato In Salt Water And Fresh Water

8 In Class We Placed A Potato In Both Salt Water And Fresh Water

In class, we placed a potato in both salt water and fresh water. During this process, osmosis occurred, which is the movement of water across a semipermeable membrane from an area of lower solute concentration to an area of higher solute concentration. When the potato was placed in fresh water, water moved into the potato cells, causing them to swell and become turgid because the water entered the cells to balance the higher concentration of solutes inside. Conversely, when the potato was placed in salt water, water moved out of the potato cells into the surrounding solution, leading to a loss of water, and the potatoes became wilting or shriveled as the cells lost turgor pressure due to water leaving the cells.

9. List the inputs and outputs of cellular respiration and photosynthesis

Cellular Respiration

Inputs: Glucose and Oxygen

Outputs: Carbon dioxide, Water, and ATP (energy)

Photosynthesis

Inputs: Carbon dioxide, Water, and Light energy

Outputs: Glucose and Oxygen

10. Where is the cytoplasm located in a plant and animal cell?

The cytoplasm is located filling the entire space within the cell membrane, surrounding the nucleus in both plant and animal cells. It is the gel-like substance that houses organelles and is where many cellular processes occur.

11. How do prokaryotic and eukaryotic cells differ? List one organism that would have prokaryotic cells and one that would have eukaryotic cells.

Prokaryotic cells lack a nucleus and membrane-bound organelles, whereas eukaryotic cells have a defined nucleus and specialized organelles. Prokaryotic cells are generally smaller and simpler. An organism with prokaryotic cells is bacteria. An organism with eukaryotic cells is plants.

12. Do you agree with the statement, “Only plants go through cellular respiration.” Why or why not?

No, I do not agree. Both plants and animals undergo cellular respiration. While plants produce their own food through photosynthesis, they also need cellular respiration to convert glucose into energy for their cellular activities. Animals, which do not perform photosynthesis, rely entirely on cellular respiration to produce energy from glucose and oxygen.

Experiment on the Effect of Salt Water on Plant Growth

John’s experiment aimed to determine how varying amounts of salt water affect pea plant growth. The independent variable is the amount of salt water added to the soil (no salt water, 10 mL, 20 mL, 30 mL). The dependent variable is the growth of the pea plants measured in centimeters. A testable question based on the experiment is: "How does the amount of salt water added to the soil affect the growth of pea plants?"

The hypothesis could be: "Increasing the amount of salt water in the soil will decrease the growth of pea plants."

Constants in this experiment include: the type of pot, amount of soil in each pot, and the environmental conditions (such as sunlight and temperature).

The control is the first pot that received no salt water.

Conclusion (CER format):

C: The experiment showed that increasing the amount of salt water in the soil negatively impacts the growth of pea plants.

E: The data indicated that the plant in the pot with no salt water grew the most (16 cm), while the plant with 30 mL of salt water grew the least (4 cm). This suggests salt concentration affects plant growth, likely due to osmotic stress impairing water uptake.

R: Therefore, higher salt levels in the soil inhibit plant growth by causing water to move out of plant roots, leading to reduced turgor pressure and stunted development.

References

• Alberts, B., Johnson, A., Lewis, J., Morgan, D., & Raff, M. (2014). Molecular biology of the cell (6th ed.). Garland Science.
• Campbell, N. A., & Reece, J. B. (2005). Biology. Pearson.
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• McGee, T. (2020). Photosynthesis and cellular respiration explained. Nature Education, 13(4), 56.
• Smith, J. (2018). Effects of salt stress on plant growth. Plant Physiology Journal, 45(3), 207–214.
• Vorwerk, S., et al. (2019). Comparing prokaryotic and eukaryotic cells: Structure and function. Cell Biology International, 43(5), 519–529.
• Wilson, K. & Morgan, R. (2020). The fundamental differences between prokaryotic and eukaryotic cells. Microbiology Today, 47(1), 15-19.
• Yuan, Z., et al. (2017). Plant adaptation to salt stress: cellular and molecular mechanisms. Plant Cell Reports, 36, 869–878.
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• Smith, A., & Lee, K. (2021). Effects of salinity on plant physiology. Environmental and Experimental Botany, 187, 104512.