Photo AI
Agricultural Science students study the general structure and function of plants - Leaving Cert Agricultural Science - Question c - 2009
Question c
Agricultural Science students study the general structure and function of plants. (i) Describe the functions of xylem tissue and phloem tissue. (ii) Explain the di... show full transcript
Worked Solution & Example Answer:Agricultural Science students study the general structure and function of plants - Leaving Cert Agricultural Science - Question c - 2009
Step 1
Describe the functions of xylem tissue and phloem tissue.
Answer
Xylem tissue has several critical functions:
- Transport of Water: It transports water and dissolved minerals from the roots to the rest of the plant.
- Support: The cell walls of xylem tissue provide structural support to the plant, helping it maintain its upright position.
Phloem tissue, on the other hand, is responsible for:
- Translocation of Food: It transports organic nutrients, particularly sugars produced through photosynthesis, from the leaves to other parts of the plant.
- Movement of Growth Regulators: Phloem is also involved in the transport of hormones and other growth regulators within the plant.
Step 2
Explain the difference between transpiration and translocation.
Answer
Transpiration is the process by which plants lose water vapor from their aerial parts, primarily through stomata in the leaves. This loss of water helps in nutrient uptake and maintains temperature.
Translocation, in contrast, refers to the movement of nutrients and other substances, particularly sugars, throughout the plant via phloem. Thus, while transpiration deals with water loss, translocation focuses on nutrient distribution.
Step 3
Describe an experiment to show water movement in a plant stem.
Answer
To demonstrate water movement in a plant stem, follow these steps:
- Plant Selection: Choose a healthy plant and place it in water.
- Cutting the Stem: Cut the stem at an angle underwater to prevent air blockage.
- Adding Dye: If desired, add a colored dye to the water to visualize the flow.
- Observation: Over time, observe the movement of water by cutting a cross-section of the stem and noting the presence of the dye in the xylem cells. This will show how water moves through the stem, indicating the transportation pathways. Finally, draw conclusions based on your findings.