Describe the expected observations and explanations when a cocoyam stalk is placed in water, a salt solution, and sodium hydroxide.

Here are the expected observations and explanations for the cocoyam stalk in each solution:

• Solution X (Water):

  • Observation: The cocoyam stalk will become turgid (firm and rigid) and may straighten or increase slightly in length.
  • Explanation: Water is a hypotonic solution relative to the plant cells. Water molecules will move from the solution (higher water potential) into the cells of the cocoyam stalk (lower water potential) by osmosis. This influx of water increases the turgor pressure inside the cells, making the stalk firm.

• Solution Y (Salt solution):

  • Observation: The cocoyam stalk will become flaccid (soft and limp) and may shrink or bend.
  • Explanation: A concentrated salt solution is a hypertonic solution relative to the plant cells. Water molecules will move out of the cells of the cocoyam stalk (higher water potential) into the surrounding salt solution (lower water potential) by osmosis. This loss of water causes the cells to lose turgor and undergo plasmolysis, making the stalk flaccid.

• Solution Z (Sodium hydroxide):

  • Observation: The cocoyam stalk will likely soften significantly, show signs of disintegration, and may appear damaged or mushy.
  • Explanation: Sodium hydroxide is a strong base that is highly corrosive. It will chemically damage and break down the cell walls, cell membranes, and proteins within the plant cells. While some initial osmotic effects might occur, the primary effect will be chemical denaturation and cell lysis, leading to the destruction of the tissue rather than a simple osmotic response like turgidity or plasmolysis.