AP BIOLOGY

Detailed explanation-1: -If the plant lacks water, stomata will close because there will not be enough water to create pressure in the guard cells for stomatal opening; this response helps the plant conserve water.

Detailed explanation-2: -On a hot, dry day (or after several days with no rain or watering), transpiration causes more water to be lost than is coming in, and the water balance within the plant can get thrown off. The dehydrated collapsing cells in the leaves and stems can no longer remain erect, and the plant begins to wilt.

Detailed explanation-3: -Wilting diminishes the plant’s ability to transpire and grow. Permanent wilting leads to plant death. Symptoms of wilting and blights resemble one another. The plants may recover during the night when evaporation is reduced as the stomata closes.

Detailed explanation-4: -Water enters a plant through its stem and travels up to its leaves. When a plant is properly hydrated, there is enough water pressure to make the leaves strong and sturdy; when a plant doesn’t get enough water, the pressure inside the stems and leaves drops and they wilt.

Detailed explanation-5: -2.3. Transpiration is a process that involves loss of water vapour through the stomata of plants. The loss of water vapour from the plant cools the plant down when the weather is very hot, and water from the stem and roots moves upwards or is ‘pulled’ into the leaves.