Plant Physiology MCQ's Q & A PDF

What process is primarily responsible for pulling water through the plant? A. Capillary action B. Transpiration C. Cohesion D. Evaporation ANSWER: B Which factor does not play a direct role in the movement of water through xylem cells? A. Tension B. Photosynthesis C. Transpiration D. Osmos...

What process is primarily responsible for pulling water through the plant? A. Capillary action B. Transpiration C. Cohesion D. Evaporation ANSWER: B Which factor does not play a direct role in the movement of water through xylem cells? A. Tension B. Photosynthesis C. Transpiration D. Osmosis ANSWER: B How does a water molecule\'s movement through the xylem begin? A. By gravitational pull B. By active transport C. Due to osmotic pressure D. Through passive diffusion ANSWER: C What ensures that the next water molecule is pulled through the xylem after one is moved? A. Cohesion of water molecules B. Soil moisture levels C. Presence of chlorophyll D. Temperature changes ANSWER: A What is the main effect of transpiration on water movement? A. It reduces the amount of water in the xylem. B. It creates a negative pressure that pulls water up. C. It stops the flow of nutrients in the xylem. D. It increases pressure in the root zone. ANSWER: B What is the primary function of root hairs in plants? A. Photosynthesis B. Nutrient absorption C. Water storage D. Gas exchange ANSWER: B Which of the following correctly describes active transport in plant roots? A. Movement from high to low concentration without energy B. Passive diffusion of nutrients C. Movement from low to high concentration with energy D. Water absorption through osmosis ANSWER: C What role do mycorrhizae play in plant nutrition? A. They produce hormones for root growth B. They increase root surface area for nutrient absorption C. They convert sunlight into energy D. They provide structural support to roots ANSWER: B Which statement correctly differentiates xylem from phloem? A. Xylem has a nucleus, while phloem does not B. Xylem tissue is living, while phloem tissue is dead C. Xylem conducts water and minerals, while phloem conducts sugars D. Xylem transports sugars, while phloem transports water ANSWER: C What is a significant structural characteristic of xylem tissue? A. Living tissue with dense cytoplasm B. Ability to perform photosynthesis C. Contains sieve tubes for transport D. Presence of lignin for reinforcement ANSWER: D How does Rhizobium benefit its relationship with plants? A. By providing water for the plant B. By increasing light absorption C. By fixing atmospheric nitrogen into soluble nitrates D. By absorbing sugars from the roots ANSWER: C Which tissue in plants is considered non-living at maturity? A. Parenchyma B. Phloem C. Collenchyma D. Xylem ANSWER: D Which component of phloem is responsible for transporting sugars? A. Companion cells B. Root hairs C. Xylem vessels D. Sieve tubes ANSWER: D What is the primary function of sieve tubes in plants? A. Facilitating gas exchange in leaves B. Storing chlorophyll for photosynthesis C. Transporting water from roots to leaves D. Transporting food produced by photosynthesis ANSWER: D Which process occurs in the cytosol and does not require oxygen? A. Electron transport chain B. Glycolysis C. Photosynthesis D. Krebs cycle ANSWER: B Which component of chloroplasts is responsible for absorbing light energy? A. Granum B. Thylakoid membrane C. Chlorophyll D. Stroma ANSWER: C What is produced during the Krebs cycle that is essential for the electron transport chain? A. NADH B. Glucose C. Acetic acid D. Acetyl coenzyme A ANSWER: A Which part of the leaf structure plays the main role in photosynthesis? A. Spongy mesophyll B. Cuticle C. Palisade mesophyll D. Upper epidermis ANSWER: C What is the ultimate source of energy for photosynthesis? A. Oxygen B. Water C. Solar energy D. Chlorophyll ANSWER: C During aerobic respiration, which intermediate product is formed from the breakdown of glucose? A. Acetyl coenzyme A B. Lactic acid C. Pyruvic acid D. Citric acid ANSWER: C What is primarily responsible for the transport of water and minerals from the roots to the leaves of a plant? A. Xylem B. Cortex C. Epidermis D. Phloem ANSWER: A Which component of the leaf structure is responsible for regulating the opening and closing of stomata? A. Lower epidermis B. Guard cells C. Vascular tissue D. Spongy mesophyll ANSWER: B What drives root pressure in plants? A. Osmosis B. The gravity effect C. Transpiration D. Photosynthesis ANSWER: A What is the primary function of stomata in leaves? A. Photosynthesis B. Gas exchange C. Nutrient absorption D. Transporting water ANSWER: B How does the cohesion-tension model describe the movement of water in plants? A. It includes the interaction of water molecules and their adhesion to plant surfaces. B. It suggests that water is pushed through the xylem by root pressure alone. C. It proposes that water molecules move independently of each other. D. It relies solely on capillary action. ANSWER: A What is transpiration primarily driven by? A. Pressure buildup in roots B. Evaporation of water from leaf surfaces C. Absorption of sunlight D. Active transport of minerals ANSWER: B