Plant Physiology SAQ's Q & A.docx

What role do root hairs play in a plant\'s nutrient absorption? ANSWER: Root hairs increase the surface area for nutrient absorption from the soil. How does active transport function in plant roots? ANSWER: Active transport moves substances from an area of low concentration to high concentration...

What role do root hairs play in a plant\'s nutrient absorption? ANSWER: Root hairs increase the surface area for nutrient absorption from the soil. How does active transport function in plant roots? ANSWER: Active transport moves substances from an area of low concentration to high concentration using energy. Describe the symbiotic relationship between mycorrhizae and plant roots. ANSWER: Mycorrhizae enhance nutrient absorption for plants while receiving sugars in return. What distinguishes xylem from phloem in terms of living tissues? ANSWER: Xylem tissue is entirely dead, while phloem tissue is composed of living cells. Explain the significance of lignin in xylem tissue. ANSWER: Lignin reinforces xylem cell walls, making them strong, water-resistant, and durable. What is the function of Rhizobium in relation to plant roots? ANSWER: Rhizobium converts atmospheric nitrogen into soluble nitrates usable by plants. Identify the two types of xylem vessels and their characteristics. ANSWER: Xylem vessels have no end walls, facilitating uninterrupted water transport. What transport role does phloem play in plants? ANSWER: Phloem transports sugars produced by photosynthesis from leaves to other plant parts. What role do guard cells play in the plant\'s leaf structure? ANSWER: Guard cells regulate the opening and closing of the stomata, which control gas exchange. How does transpiration contribute to water movement within plants? ANSWER: Transpiration creates tension that helps pull water up through the xylem from the roots to the leaves. Explain the cohesion-tension model in the context of water transport in plants. ANSWER: The cohesion-tension model describes how water molecules stick together, creating tension that aids in the upward movement of water. What is osmosis and how does it relate to root pressure? ANSWER: Osmosis is the movement of water from high to low concentration, and it generates root pressure by drawing water into root hairs. Describe the process of transpiration and its significance for plants. ANSWER: Transpiration is the loss of water vapor from leaves, crucial for cooling the plant and driving water movement. What is the primary function of sieve tubes in plants? ANSWER: Sieve tubes transport food produced by photosynthesis throughout the plant. Identify the primary function of xylem in plant anatomy. ANSWER: Xylem is responsible for the transport of water and minerals from the roots to the leaves. What determines the rate of transpiration in leaves? ANSWER: The rate of transpiration in leaves is influenced by factors such as humidity, temperature, and the opening of stomata. Explain the role of chlorophyll in photosynthesis. ANSWER: Chlorophyll absorbs light energy from the sun, which is crucial for driving the photosynthesis process. What are the two main stages of aerobic respiration? ANSWER: The two main stages of aerobic respiration are glycolysis and the Krebs cycle. What is the relationship between stomata and gas exchange in plants? ANSWER: Stomata facilitate gas exchange by allowing oxygen, water, and carbon dioxide to diffuse in and out of the plant. Describe the function of the cuticle in a leaf. ANSWER: The cuticle prevents water loss from the leaf\'s surface, helping to retain moisture. What occurs during glycolysis, and where does it take place? ANSWER: Glycolysis breaks down glucose into two molecules of pyruvic acid and occurs in the cytosol. What is the role of companion cells in the sieve tube? ANSWER: Companion cells control the activities and regulate the functioning of sieve tubes. How does the structure of leaves enhance photosynthesis? ANSWER: Leaves have a flat structure that maximizes light absorption for efficient photosynthesis. What is the result of the breakdown of pyruvic acid in the mitochondria? ANSWER: Pyruvic acid is converted into acetyl coenzyme A, which enters the Krebs cycle. Explain how water movement in plants is affected by osmotic pressure. ANSWER: Osmotic pressure helps pull water molecules through the xylem cells, facilitating their upward movement in plants. What role does transpiration play in the movement of water in plants? ANSWER: Transpiration creates a negative pressure that pulls water upwards through the xylem. Describe the energy requirements for water transport through the plant\'s xylem. ANSWER: The transport of water through the xylem does not require energy; it occurs passively through physical processes. How does the cohesion of water molecules contribute to water transport in plants? ANSWER: Cohesion allows water molecules to stick together, enabling them to be pulled in a continuous column through the xylem. Identify the relationship between osmosis and water movement in xylem. ANSWER: Osmosis drives water molecules into the xylem and maintains the flow by pulling the next molecule along. What is the significance of the xylem in the plant\'s water transport system? ANSWER: The xylem is essential for conducting water from the roots to the rest of the plant, enabling vital functions.