What is photosynthesis in crops?
Photosynthesis is the process by which green crop plants convert sunlight into food using carbon dioxide and water.
Why is photosynthesis important for crop growth?
Photosynthesis produces glucose, providing energy required for crop growth, development, yield formation, and survival.
Which pigment is essential for photosynthesis in crops?
Chlorophyll is the primary green pigment enabling crops to absorb sunlight for photosynthesis.
Where does photosynthesis occur in crop plants?
Photosynthesis mainly occurs in chloroplasts of green leaves and young green stems.
What raw materials are required for photosynthesis?
Photosynthesis requires sunlight, carbon dioxide, water, and chlorophyll to produce food in crops.
What is the end product of photosynthesis?
The main products are glucose and oxygen, supporting crop metabolism and atmospheric balance.
Why are leaves called food factories of crops?
Leaves contain chloroplasts that manufacture food through photosynthesis, supplying energy to entire crop plants.
How does sunlight affect photosynthesis in crops?
Higher light intensity increases photosynthesis up to an optimum level, beyond which efficiency declines.
What role does carbon dioxide play in photosynthesis?
Carbon dioxide provides carbon atoms necessary for glucose synthesis during photosynthesis in crops.
How do stomata help photosynthesis?
Stomata regulate gas exchange, allowing carbon dioxide entry and oxygen release during photosynthesis.
Why is water essential for photosynthesis?
Water supplies hydrogen ions and electrons required for glucose formation during photosynthesis.
Which wavelength of light is most effective for photosynthesis?
Red and blue wavelengths are most effective for driving photosynthesis in crop plants.
What happens during the light reaction of photosynthesis?
Light energy splits water molecules, releasing oxygen and producing energy-rich molecules.
What occurs during the dark reaction of photosynthesis?
Carbon dioxide is fixed into glucose using energy produced during light reactions.
What is the Calvin cycle?
The Calvin cycle is the biochemical pathway converting carbon dioxide into sugars in crops.
How does temperature affect photosynthesis?
Photosynthesis increases with temperature up to an optimum, then declines due to enzyme denaturation.
Why do crops appear green?
Chlorophyll reflects green light while absorbing red and blue wavelengths for photosynthesis.
Which crops show high photosynthetic efficiency?
C4 crops like maize and sugarcane show higher photosynthetic efficiency than C3 crops.
What are C3 crops?
C3 crops fix carbon dioxide directly into a three-carbon compound during photosynthesis.
What are C4 crops?
C4 crops initially fix carbon dioxide into four-carbon compounds, reducing photorespiration losses.
What is CAM photosynthesis?
CAM plants fix carbon dioxide at night, conserving water in arid conditions.
Why is photosynthesis lower during drought?
Water stress causes stomatal closure, limiting carbon dioxide intake and reducing photosynthesis.
How does nitrogen affect photosynthesis?
Nitrogen is essential for chlorophyll synthesis and enzyme activity in photosynthesis.
Why is magnesium important for photosynthesis?
Magnesium is a central atom in chlorophyll molecules, essential for light absorption.
How does iron influence photosynthesis?
Iron supports chlorophyll formation and electron transport during photosynthesis.
What is photorespiration?
Photorespiration is a wasteful process reducing photosynthetic efficiency in C3 crops.
Why is photorespiration undesirable?
It consumes energy and releases carbon dioxide without producing glucose.
How do C4 crops reduce photorespiration?
C4 crops concentrate carbon dioxide around Rubisco, minimizing photorespiration.
What enzyme is crucial for carbon fixation?
Rubisco is the primary enzyme responsible for carbon dioxide fixation in photosynthesis.
Why is Rubisco considered inefficient?
Rubisco can bind oxygen instead of carbon dioxide, causing photorespiration.
How does leaf area affect photosynthesis?
Greater leaf area increases light interception, enhancing photosynthetic capacity.
Why do young leaves photosynthesize more efficiently?
Young leaves contain more active chloroplasts and higher chlorophyll concentration.
How does crop spacing affect photosynthesis?
Proper spacing ensures optimal light penetration and reduces shading among plants.
What role does oxygen play in photosynthesis?
Oxygen is a byproduct of photosynthesis and supports respiration in living organisms.
How does altitude influence photosynthesis?
Lower carbon dioxide pressure at high altitudes can reduce photosynthetic rates.
Why is photosynthesis vital for crop yield?
Higher photosynthesis increases carbohydrate production, directly improving yield.
How does soil moisture affect photosynthesis?
Adequate soil moisture supports water availability necessary for photosynthesis.
Why do shaded crops yield less?
Reduced light limits photosynthesis, decreasing carbohydrate production and yield.
How does cloud cover affect photosynthesis?
Clouds reduce light intensity, temporarily lowering photosynthetic rates.
What is gross photosynthesis?
Gross photosynthesis is the total rate of glucose production before respiratory losses.
What is net photosynthesis?
Net photosynthesis is glucose production after subtracting respiration losses.
Why is net photosynthesis important?
It represents actual energy available for crop growth and yield.
How does chlorophyll content affect photosynthesis?
Higher chlorophyll content enhances light absorption and photosynthetic efficiency.
What causes chlorosis in crops?
Chlorosis results from nutrient deficiencies reducing chlorophyll synthesis.
How does sulfur influence photosynthesis?
Sulfur supports protein synthesis, indirectly enhancing photosynthetic enzymes.
Why is potassium important for photosynthesis?
Potassium regulates stomatal movement, controlling gas exchange efficiency.
How does salinity affect photosynthesis?
Salinity causes osmotic stress, reducing water uptake and photosynthetic activity.
What is the role of light duration in photosynthesis?
Longer daylight increases total photosynthesis if other factors remain optimal.
Why does photosynthesis stop at night?
Absence of sunlight prevents light-dependent reactions of photosynthesis.
How do weeds affect crop photosynthesis?
Weeds compete for light, reducing photosynthesis in crop plants.
What is source-sink relationship in crops?
Photosynthetic leaves supply sugars to growing organs like grains and roots.
How does defoliation affect photosynthesis?
Leaf loss reduces photosynthetic area, lowering food production.
Why is photosynthesis slower in winter crops?
Lower temperatures and light intensity reduce enzyme activity.
How does CO₂ concentration affect photosynthesis?
Higher carbon dioxide concentration increases photosynthesis until saturation.
What is the compensation point in photosynthesis?
It is the light level where photosynthesis equals respiration.
Why is photosynthesis essential for food chains?
It forms the base of food chains by producing organic matter.
How does plant age affect photosynthesis?
Photosynthesis declines in older plants due to reduced chlorophyll and enzyme activity.
Why do crops need sunlight daily?
Continuous sunlight ensures consistent photosynthetic food production.
How do cloudy days affect crop productivity?
Reduced sunlight lowers photosynthesis, slightly decreasing growth rates.
What role do enzymes play in photosynthesis?
Enzymes catalyze biochemical reactions converting carbon dioxide into sugars.
Why is photosynthesis considered anabolic?
It synthesizes complex molecules like glucose from simpler substances.
How does air pollution affect photosynthesis?
Pollutants damage chlorophyll and block stomata, reducing photosynthetic efficiency.
What is the role of phosphorus in photosynthesis?
Phosphorus is required for ATP formation during energy transfer.
Why are chloroplasts essential?
Chloroplasts house chlorophyll and enzymes necessary for photosynthesis.
How does waterlogging affect photosynthesis?
Waterlogging restricts root respiration, reducing water and nutrient uptake.
Why is photosynthesis slower in nutrient-poor soils?
Lack of essential nutrients limits chlorophyll and enzyme production.
How does plant density affect photosynthesis?
Excessive density causes shading, reducing individual plant photosynthesis.
What is the action spectrum of photosynthesis?
It shows effectiveness of different light wavelengths in photosynthesis.
Why is red light efficient for photosynthesis?
Red light strongly excites chlorophyll molecules, enhancing energy absorption.
How does humidity influence photosynthesis?
High humidity reduces transpiration stress, supporting better photosynthesis.
Why do legumes photosynthesize efficiently?
Nitrogen fixation supports higher chlorophyll and enzyme synthesis.
What is photophosphorylation?
It is ATP formation using light energy during photosynthesis.
How does leaf orientation affect photosynthesis?
Optimal leaf angle maximizes sunlight interception throughout the day.
Why is photosynthesis lower under stress conditions?
Stress disrupts enzyme activity, gas exchange, and water balance.
How does pruning affect photosynthesis?
Pruning improves light penetration, enhancing photosynthesis in remaining leaves.
Why is photosynthesis essential for oxygen supply?
Photosynthesis releases oxygen necessary for aerobic life.
How does frost damage photosynthesis?
Freezing damages chloroplasts and enzymes, stopping photosynthesis.
Why are green manures beneficial?
They enhance soil fertility, indirectly improving photosynthetic efficiency.
How does irrigation scheduling affect photosynthesis?
Timely irrigation maintains water availability, supporting optimal photosynthesis.
Why is photosynthesis critical in sustainable agriculture?
Efficient photosynthesis improves yield while reducing external inputs.
How does plant breeding improve photosynthesis?
Breeding selects traits enhancing light use efficiency and carbon fixation.
Why is photosynthesis studied in crop science?
Understanding photosynthesis helps improve crop productivity and food security.
How does leaf thickness affect photosynthesis?
Thinner leaves allow better light penetration, improving photosynthetic efficiency in many crop plants.
Why do broad leaves enhance photosynthesis?
Broad leaves provide larger surface area for light absorption and gas exchange.
How does wind influence photosynthesis?
Moderate wind improves carbon dioxide diffusion but strong winds may damage leaves.
What is light saturation point in photosynthesis?
It is the light intensity beyond which photosynthesis no longer increases.
Why does excessive light reduce photosynthesis?
Too much light damages chlorophyll and photosynthetic machinery, causing photoinhibition.
How does soil fertility affect photosynthesis?
Fertile soils supply nutrients needed for chlorophyll and enzyme synthesis.
Why is photosynthesis lower in compacted soils?
Compacted soils restrict root growth and water uptake, reducing photosynthesis.
How does intercropping affect photosynthesis?
Proper intercropping improves light use efficiency and overall photosynthesis.
What is canopy photosynthesis?
It is the total photosynthesis of all leaves within a crop canopy.
Why is canopy management important?
Proper canopy structure maximizes light interception and photosynthesis.
How does leaf senescence affect photosynthesis?
Aging leaves lose chlorophyll, reducing photosynthetic activity.
Why does nitrogen deficiency reduce photosynthesis?
Nitrogen deficiency limits chlorophyll formation and photosynthetic enzymes.
How does zinc affect photosynthesis?
Zinc activates enzymes involved in carbohydrate synthesis during photosynthesis.
What role does copper play in photosynthesis?
Copper supports electron transport in photosynthetic reactions.
Why are irrigated crops more productive?
Adequate water supports uninterrupted photosynthesis and nutrient uptake.
How does drought stress affect chlorophyll?
Drought reduces chlorophyll content, lowering photosynthetic efficiency.
What is mesophyll tissue?
Mesophyll contains chloroplast-rich cells where most photosynthesis occurs.
Why is photosynthesis important for root growth?
Roots depend on carbohydrates produced through photosynthesis.
How does shading by tall crops affect short crops?
Shading reduces light availability, lowering photosynthesis in shorter crops.
Why do crops photosynthesize less during heat stress?
High temperatures denature enzymes involved in photosynthesis.
How does irrigation water quality affect photosynthesis?
Saline or polluted water disrupts physiological processes, reducing photosynthesis.
What is chlorophyll fluorescence?
It is light emitted by chlorophyll indicating photosynthetic efficiency.
Why is chlorophyll measurement important?
It helps assess plant health and photosynthetic capacity.
How does pest attack affect photosynthesis?
Pests damage leaf tissues, reducing photosynthetic area.
Why does defoliation reduce yield?
Reduced photosynthesis limits carbohydrate supply for grain filling.
How does crop variety influence photosynthesis?
Improved varieties have higher light use efficiency and carbon fixation.
Why is photosynthesis crucial during flowering?
Adequate photosynthesis supports flower development and fruit set.
How does grain filling depend on photosynthesis?
Carbohydrates synthesized through photosynthesis are transported to grains.
Why is photosynthesis essential in fodder crops?
It determines biomass production and nutritional quality.
How does CO₂ enrichment improve photosynthesis?
Higher CO₂ increases carbon fixation and photosynthetic rates.
Why is photosynthesis lower in polluted environments?
Pollutants damage stomata and chloroplasts.
How does light quality affect photosynthesis?
Different wavelengths influence chlorophyll absorption efficiency.
Why do crops photosynthesize less under smog?
Smog reduces sunlight reaching leaves.
How does water stress affect stomata?
Stomata close to conserve water, reducing carbon dioxide intake.
Why is early morning sunlight beneficial?
It provides optimal light without heat stress.
How does plant nutrition improve photosynthesis?
Balanced nutrients enhance chlorophyll synthesis and enzyme activity.
Why does photosynthesis decline after maturity?
Leaf aging and reduced metabolic activity lower photosynthesis.
How does crop rotation affect photosynthesis?
Rotation improves soil fertility, indirectly enhancing photosynthesis.
Why are healthy leaves shiny green?
High chlorophyll content indicates active photosynthesis.
How does lodging affect photosynthesis?
Fallen crops receive less light, reducing photosynthesis.
Why is photosynthesis vital for biomass accumulation?
Biomass formation depends on carbohydrate synthesis.
How does transplant shock affect photosynthesis?
Root disturbance temporarily reduces water uptake and photosynthesis.
Why do seedlings photosynthesize less initially?
Limited leaf area reduces early photosynthesis.
How does light interception affect yield?
Better light interception increases photosynthesis and yield.
Why is photosynthesis reduced under nutrient stress?
Enzyme and pigment synthesis becomes limited.
How does organic farming influence photosynthesis?
Improved soil health supports better photosynthetic performance.
Why is photosynthesis essential for carbon cycling?
It removes atmospheric carbon dioxide and stores carbon.
How does foliar nutrition affect photosynthesis?
Foliar sprays supply nutrients directly to leaves, boosting photosynthesis.
Why is photosynthesis critical in climate change mitigation?
It absorbs carbon dioxide, reducing greenhouse effects.
How does plant spacing improve photosynthesis?
Adequate spacing prevents shading and competition.
Why do crops photosynthesize less in foggy weather?
Fog reduces light intensity reaching leaves.
How does mulching affect photosynthesis?
Mulching conserves moisture, indirectly supporting photosynthesis.
Why is photosynthesis important in horticultural crops?
It determines fruit size, color, and quality.
How does pruning fruit trees improve photosynthesis?
Pruning enhances light penetration within canopy.
Why does photosynthesis slow during nutrient toxicity?
Excess nutrients damage metabolic processes.
How does plant stress signaling affect photosynthesis?
Stress hormones reduce photosynthetic activity.
Why is photosynthesis the foundation of agriculture?
All crop production depends on photosynthetic food synthesis.
How does irrigation frequency influence photosynthesis?
Regular irrigation maintains optimal physiological conditions.
Why is photosynthesis central to food security?
It directly determines crop productivity and yield stability.
How does soil organic matter affect photosynthesis?
Organic matter improves nutrient availability and water retention.
Why is photosynthesis essential for sustainable yields?
Efficient photosynthesis ensures consistent production with fewer inputs.
How does climate affect photosynthesis in crops?
Temperature, light, and rainfall strongly influence photosynthetic rates.
Why is photosynthesis studied in crop physiology?
It explains growth patterns, stress responses, and yield formation.