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Plant physiology is the study of how plants function and grow, encompassing a wide range of processes such as photosynthesis, respiration, nutrient absorption, and more. The study of plants and their behaviour, including their responses to environmental stimuli, is typically referred to as “plant physiology” or “botany.” In this article, we’ll explore and provide detailed answers to help you understand these fundamental concepts.
Top 25 Questions Related to Plant Physiology
Q1. What is plant physiology?
Ans. Plant physiology is the study of how plants function, including their growth, development, and response to environmental factors.
Top 25 Questions on Plant Physiology Video Session
Q2. What is photosynthesis, and how does it work?
Ans. Photosynthesis, occurring in chloroplasts, is the pivotal process through which green plants, algae, and certain bacteria transform sunlight, carbon dioxide, and water into glucose and oxygen. It relies on chlorophyll’s light absorption to split water molecules, generating oxygen and essential chemical compounds that culminate in glucose production. This fundamental process sustains oxygen levels and fuels energy for diverse life forms on our planet.
Q3. What is transpiration?
Ans. Transpiration is the loss of water vapour from plant leaves through tiny pores called stomata, which helps in nutrient uptake and cooling.
Q4. What is the role of plant hormones?
Ans. Plant hormones, also known as phytohormones, play a crucial role in regulating various growth and developmental processes in plants. They control activities like cell division, elongation, differentiation, and responses to environmental stimuli. Plant hormones include auxins, gibberellins, cytokinins, abscisic acid, and ethylene, each with specific functions in processes such as seed germination, root and shoot growth, flowering, and stress responses, ensuring plants adapt to their surroundings and maintain their overall health and survival.
Q5. How do plants absorb nutrients?
Ans. Plants absorb nutrients through their roots via a process called active transport, utilising specialised transport proteins to uptake essential minerals and water from the soil. This allows them to fuel growth and maintain their vital functions.
Q6. What is the importance of soil pH for plant growth?
Ans. Soil pH is essential for plant growth as it impacts nutrient accessibility. Plants generally flourish within a slightly acidic to neutral pH range (approximately 6 to 7). Extreme pH levels can hinder nutrient absorption, resulting in stunted growth and reduced vitality. Maintaining the appropriate soil pH guarantees that plants can obtain vital nutrients for their best growth.
Q7. What is the role of gibberellins in plant growth?
Ans. Gibberellins promote stem elongation, fruit development, and seed germination in plants.
Q8. What are the effects of excess fertiliser use on plants?
Ans. Over-fertilization can lead to nutrient imbalances, soil degradation, and environmental pollution.
Q9. What is the role of the plant cell wall?
Ans. The plant cell wall provides structural support and protection, allowing cells to maintain their shape.
Q10. How do plants defend themselves against herbivores and pathogens?
Ans. Plants employ physical barriers, chemical toxins, and signaling molecules to deter herbivores and pathogens.
Q11. What is the difference between anaerobic and aerobic respiration in plants?
Ans. Aerobic respiration in plants occurs in the presence of oxygen and produces energy more efficiently, yielding more ATP. In contrast, anaerobic respiration occurs in the absence of oxygen and is less efficient, producing less ATP and often leading to the accumulation of toxic byproducts like ethanol.
Q12. How do plants adapt to environmental stress?
Ans. Plants adapt to stress through mechanisms like drought tolerance, cold resistance, and altering their growth patterns.
Q13. What is the role of chlorophyll in photosynthesis?
Ans. Chlorophyll molecules capture light energy and convert it into chemical energy, initiating the photosynthesis process.
Q14. What are stomata, and what is their function?
Ans. Stomata are small openings in plant leaves that regulate gas exchange, including the uptake of carbon dioxide and release of oxygen.
Q15. How do plants respond to light and gravity?
Ans. Plants exhibit phototropism (growth towards light) and gravitropism (response to gravity) through hormone-controlled growth.
Q16. What is the role of mycorrhizal associations in plants?
Ans. Mycorrhizal fungi form symbiotic relationships with plant roots, enhancing nutrient absorption and plant health.
Q17. How do plants transport water and nutrients from roots to leaves?
Ans. The transpiration-cohesion-adhesion mechanism allows water and nutrients to move from roots to leaves through the xylem.
Q18. What is the significance of plant reproduction?
Ans. Plant reproduction ensures the continuation of species through processes like pollination, seed formation, and vegetative propagation.
Q19. What are the main functions of plant roots?
Ans. Plant roots serve vital roles in a plant’s life. They anchor the plant securely in the soil, providing stability and support. These roots also act as nature’s nutrient sponge, absorbing water and essential nutrients to fuel the plant’s growth and overall health. Additionally, roots function as a storage unit, storing carbohydrates and other valuable resources to ensure the plant’s continuous nourishment and development.
Q20. How do plants respond to environmental cues like temperature and photoperiod?
Ans. Plants exhibit phenotypic plasticity, adjusting their growth and development in response to changing environmental conditions.
Q21. What is the role of nitrogen fixation in plants?
Ans. Nitrogen-fixing bacteria help convert atmospheric nitrogen into a usable form for plants, promoting their growth.
Q22. What is the relationship between light intensity and plant photosynthesis?
Ans. Light intensity directly affects the rate of photosynthesis, with plants requiring adequate light for optimal growth.
Q23. How do plants respond to water stress?
Ans. Plants employ strategies like closing stomata and adjusting their growth to conserve water during drought conditions.
Q24. What is the role of abscisic acid in plant stress responses?
Ans. Abscisic acid helps plants respond to stress by regulating stomatal closure and initiating protective mechanisms.
Q25. How do plants sense and respond to gravity?
Ans. Plants sense gravity through specialised cells called osteocytes in their roots and stems, which contain dense organelles called statoliths. When these statoliths settle due to gravity, they trigger signals that guide the plant’s growth and orientation, allowing it to respond by growing roots downward and shoots upward.
Conclusion
Plant physiology is a fascinating field that delves into the intricate mechanisms governing the life and growth of plants. Understanding how plants function, from photosynthesis to hormonal regulation and responses to environmental cues, is crucial not only for agricultural and ecological purposes but also for our planet’s overall well-being. Plants are the foundation of terrestrial ecosystems, providing food, oxygen, and countless resources. By exploring these top 25 questions and answers on plant physiology, we gain valuable insights into the remarkable adaptations and processes that allow plants to thrive in diverse environments and sustain life on Earth. Studying plant physiology is not only a scientific endeavour but also an appreciation of the incredible complexity and resilience of the plant kingdom.
Frequently Asked Questions on Plant Physiology
What is plant physiology?
Plant physiology is the study of how plants function, including their growth, development, and response to environmental factors.
What is photosynthesis, and how does it work?
Photosynthesis is the process by which plants convert sunlight, carbon dioxide, and water into glucose and oxygen. It occurs in chloroplasts and is essential for sustaining life on Earth.
What is transpiration?
Transpiration is the loss of water vapour from plant leaves through tiny pores called stomata, which aids in nutrient uptake and cooling.
What are plant hormones, and what roles do they play?
Plant hormones, also known as phytohormones, regulate various growth and developmental processes in plants, including cell division, elongation, and responses to environmental stimuli.
How do plants absorb nutrients?
Plants absorb nutrients through their roots via a process called active transport, utilising specialised transport proteins to uptake minerals and water from the soil.
