Draw a line graph on the grid provided, to show the effect of the salt solution on germination. Explain the effect of increasing the salt concentration on seed germination.

Here are the solutions to the questions:

(i) Draw a line graph on the grid provided, to show the effect of the salt solution on germination.

To draw a line graph, specific data points for salt concentration and germination percentage are required. This data is not provided in the image. Therefore, I cannot draw the graph.

(ii) Explain the effect of increasing the salt concentration on seed germination.

Increasing the salt concentration negatively affects seed germination in two main ways:

• Water potential and osmosis: A high salt concentration in the surrounding solution lowers its water potential. This creates a water potential gradient where the water potential outside the seed is lower than inside the seed cells. Consequently, water moves out of the seed by osmosis, or the seed is unable to absorb the necessary water for germination. Seeds require water to activate metabolic processes and swell.
• Enzyme inhibition/denaturation: High salt concentrations can also inhibit or denature the enzymes within the seed. These enzymes are vital for respiration and the breakdown of stored food reserves (like starch and proteins) into usable energy and building blocks for the embryo's growth. Without proper enzyme function, the seed cannot metabolize its food stores, thus preventing germination.