Question 1: Define Xylem and describe its primary function in plants.

Answer: Xylem is a type of vascular tissue in plants responsible for transporting water and minerals from the roots to the leaves.

Question 2: Explain how Phloem contributes to the distribution of nutrients in a plant.

Answer: Phloem transports sugars and organic nutrients produced via photosynthesis from the leaves to other parts of the plant.

Question 3: Describe one mechanism by which Xylem transports water against gravity.

Answer: Xylem uses capillary action and transpiration pull created by water evaporation from leaves to move water upward.

Question 1: Calculate the force (in Newtons) required to lift water 2 meters in a plant's Xylem tube, assuming the density of water is 1000 kg/m³ and gravitational acceleration is 9.81 m/s². Use the formula: Force = mass × gravity, where mass = volume × density. Assume the volume of water moved in this height is 1 mL (0.001 L).

Answer: Force = 0.00981 N

Question 1: Design a simple experiment to test how Xylem function is affected by microgravity conditions. Include the variables you would control and measure.

Answer: The experiment would involve growing plants in a controlled environment with microgravity conditions (such as on a space station). Variables to control include soil type, water amount, light exposure, and plant species. Variables to measure would include water uptake rate, plant height, and xylem vessel integrity over time.

Question 2: Identify two safety precautions that must be considered when conducting plant experiments in a space environment.

Answer: Ensuring proper containment of water to prevent spillage in microgravity and avoiding exposure to any chemicals used in plant growth media that could be hazardous in confined environments.

Question 1: A study reports that in microgravity, the rate of Phloem transport of sugars decreases by 40% compared to Earth conditions. What could be the implications for growing crops on a space station?

Answer: A decrease in Phloem transport could lead to reduced nutrient distribution within the plant, resulting in slower growth, lower crop yields, and potential difficulties in maintaining a sustainable food supply in space.

Question 1: Discuss how the structure of Xylem and Phloem tissues makes them suitable for their functions, especially in the context of space agriculture.

Answer: Xylem vessels are thick-walled and contain lignin, providing structural support and enabling water transport via capillary action and transpiration, which is vital in gravity-dependent environments. Phloem consists of sieve tubes and companion cells, allowing efficient transport of organic nutrients. In space, adaptations such as modified vessel structure could help maintain water and nutrient flow despite microgravity conditions, supporting sustainable plant growth.

Question 1: Explain how understanding plant vascular tissues can contribute to the development of life support systems in long-duration space missions.

Answer: Knowledge of Xylem and Phloem can help engineer efficient plant growth systems that optimise water and nutrient transport in microgravity, ensuring a sustainable food supply and oxygen regeneration for astronauts on long missions.