2-1), the net reaction, following equations 2-1 through 2-4 is:
CO2 + 10 photons + H2O = CH2O + 1/2O2.(2-5)
Figure 2.1 - Schematic representation of mechanisms involved in plant photosynthesis Experimental data indicates that between 8 and 12 photons are required for fixation of one molecule of CO2.
Osmotic stress responses of water content, photosynthetic parameters and biomass production were investigated in wheat-Aegilops biuncialis amphiploids and in wheat genotypes to clarify whether they can use to improve the drought tolerance of bread wheat. A decrease in the osmotic pressure of the medium resulted in considerable water loss, stomatal closure and a decreased CO2 assimilation rate for the wheat genotypes, while the changes in these parameters were moderate for the amphiploids. Maximal assimilation rate was maintained at high level even under severe osmotic stress in the amphiploids, while it decreased substantially in the wheat genotypes. Nevertheless, the effective quantum yield of PS II was higher and the quantum yield of non-photochemical quenching of PS II and PS I was lower for the amphiploids than for the wheat cultivars. Parallel with this, higher cyclic electron flow was detected in wheat than in the amphiploids. The elevated photosynthetic activity of amphiploids under osmotic stress conditions was manifested in higher biomass production by roots and shoots as compared to wheat genotypes. These results indicate that the drought-tolerant traits of Ae. biuncialis can be manifested in the wheat genetic background and these amphiploids are suitable genetic materials for improving drought tolerance of wheat.
Count the bubbles to measure the rate of photosynthesis
Photosynthesis occurs in plants, algae and photosynthetic bacteria, while biomass conversion reactions often occur in non-photosynthetic microorganisms.
9(l) Primary Productivity of Plants - Physical geography
Localized episodes of such cultural elaborationhave always been associated with rapid population growth. Reasonsfor the abundance of resources that promoted this growth varyfrom one case to another. In some instances, a population movedinto a new region with previously untapped resources; in otherinstances the development or adoption of new crops, newtechnologies, or new social strategies enhanced production. Butthe Sumerians, the Greeks, the Romans, the Mayas, and even theEaster Islanders all experienced a surge of creative activity astheir populations grew rapidly.
GCSE Physics – unit 1, unit 2 and unit 3. AQA
Starvation will be a direct outcome of thedepletion of energy resources. Today's dense population isdependent for its food supply on mechanized agriculture andefficient transportation. Energy is used to manufacture andoperate farm equipment, and energy is used to take food tomarket. As less efficient energy resources come to be used, foodwill grow more expensive and the circle of privileged consumersto whom an adequate supply is available will continue toshrink.
Carbon Cycle and the Earth's Climate - Columbia …
While no single energy source is ready to take theplace of fossil fuels, their diminishing availability may beoffset by a regimen of conservation and a combination ofalternative energy sources. This will not solve the problem,however. As long as population continues to grow, conservation isfutile; at the present rate of growth (1.6% per year), even a 25%reduction in resource use would be obliterated in just overeighteen years. And the use of any combination of resources thatpermits continued population growth can only postpone the day ofreckoning.