How does light intensity affect gas exchange?
When the light intensity is low, the light received is weak and therefore the plant will produce more photosynthetic pigments, more especially chlorophyll (Chl) b, leading to reduction of Chl a/b ratio as well as reduction in the gas exchange (Anet) [6].
What does the initial slope of a light compensation response curve represent?
The initial slope of the light response curve (α) may be described as the apparent maximum quantum yield. The qualification “apparent” is important since the estimate is based on incident not absorbed light: if reflected and transmitted light are taken into account, the true maximum quantum yield (ϕ) is obtained.
What is the meaning by PI in photosynthesis?
Abstract. Photosynthesis-irradiance (PI) curves are extensively used in field and laboratory research to evaluate the photon-use efficiency of plants.
Why do you think higher and higher light intensities do not cause an ever increasing rate of CO2 use?
However, once the light intensity gets high enough, the rate won’t increase anymore because there will other factors that are limiting the rate of photosynthesis. A limiting factor could be the amount of chlorophyll molecules that are absorbing the light.
Why did the shade have lower photosynthetic and Transpirational rates?
Both reduced enzyme activity and net photosynthetic rate could be attributed to the lowered whole plant biomass productivity. The increased stomatal diffusive resistance in shade plants, is associated with the low rate of transpiration.
Why is light intensity a limiting factor for photosynthesis?
Light. As light intensity increases so too does the rate of photosynthesis until a certain point where the graph levels off. At lower light intensities, light is the limiting factor because an increase in light causes an increase in photosynthesis.
What is light saturation point?
(The light saturation point is the intensity at which additional increases in light do not increase photo- synthesis.) This means the value of supplemental lighting is marginalized at a low CO2 concentration.
Who accurately estimated the value of pi?
mathematician Archimedes of Syracuse
The Ancient Greek mathematician Archimedes of Syracuse (287-212 BC) is largely considered to be the first to calculate an accurate estimation of the value of pi.
What does the net photosynthetic light-response curve tell us?
Introduction The net photosynthetic light-response curve (PN/I curve) describes the net CO2 assimilation by a plant leaf (PN) as a function of an increase in the photosynthetic photon flux density (I) from the total absence of light to a high level of light, e.g. 2,000 µmol(photon) m–2 s–1.
What is the phase response curve?
The Phase Response Curve (PRC) is a curve describing the relationship between a stimulus, such as light exposure, and a response, in this case a shift in circadian rhythm (phase shift).
What is a light curve?
In the study of objects which change their brightness over time, such as novae , supernovae, and variable stars, the light curve is a simple but valuable tool to a scientist. If playback doesn’t begin shortly, try restarting your device. Videos you watch may be added to the TV’s watch history and influence TV recommendations.
How is the light-response curve truncated by a RuBisCO limitation?
The light-response curve is truncated by the transition to a Rubisco limitation and the lower the irradiance at the transition, the higher the value of . There is a gradient in light absorption through the leaf which influences the photosynthetic capacity of different layers within the leaf.