Dendrochronology, or tree-ring dating, provides absolute dates in two different ways: directly, and by calibrating radiocarbon results. Cross-dating determines the age of undated wood by directly matching ring patterns with trees of known age.
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P I and PII are proteic compounds present in the thylakoid membrane that contain about 300 chlorophyll molecules each.
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<u>Step I</u></em></h2>
First of all light with a wavelength of 690nm is absorbed by P II. The light excites an electron that leads to the photolysis of water(H2O--->2H+ +2e- + 1/2O2). The two electrons released go into the electron transport chain. The second compound in electron transport chain is plastoquinone that is reduced when it accepts electrons then oxidised when it loses them to P I. The next two compounds are cytocromes that make hydrogen protons go inside the thylakoid when they recieve the electrons.(I will mention what happens to the H+ in the second step). The next compound in the electron transport chain is a compound that contains Fe and S. The electrons finally reach the last step: Reduction of NADP+ to NADPH+H+.
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Step II</u></em></h2>
In the second step is ATP synthesis. Hydrogen protons accumulate inside the thylakoid membrane. An electrochemical gradient is formed. The protons can leave the thylakoid according to this gradient through an enzyme.
When the protons flow through , it turns ADP into ATP.
<u>To sumarize: the role of P II is O2 production through photolysis and ATP synthesis(indirectly) The role of P I is NADPH+H+ synthesis.</u>
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Answer: A. Pyruvic acid, the product of glycolysis, is the starting block for both the Krebs cycle and fermentation.
Explanation: Glycolysis is a metabolic pathway that oxidize glucose producing pyruvic acid and few ATP molecules. If the cellular microenvironment is aerobic, pyruvic acid is converted in Acetyl coA and enters into Krebs cycle and later into electron transport chain, which produce large amounts of ATP. If the cellular microenvironment is anaerobic, fermentation occurs and pyruvic acid is converted in lactic acid, ethanol, etc, producing only few ATP.
Answer:
organic fertilizer can cause less harm to the plant & environment as it isn't toxic (completely natural) as opposing to fertilizers, which is filled with toxic chemicals.
Answer:
B
Explanation:
Valleys are created by streams of running water
