Check the statements about light-independent reactions in photosynthesis that are true. light-independent reactions requires carbon dioxide (co2). light-independent reactions occur in the thylakoid membrane. light-independent reactions involve the splitting of water molecules. light-independent reactions produce carbohydrates.

The true statments are: Light-independent reactions requires carbon dioxide (CO2) and Light-independent reactions produce carbohydrates.

The light-independent reactions are the second stage of photosynthesis, also called dark reactions because they are not directly driven by light. These reactions convert carbon dioxide (CO2) and other compounds into glucose. Unlike the light-dependent reactions (first stage of photosynthesis), which take place in the thylakoid membrane, the reactions of the Calvin cycle take place in the stroma (the inner space of chloroplasts). Dark reactions take the products (ATP and NADPH) of light-dependent reactions and use it for further chemical processes. Light-independent reactions known as the Calvin cycle consists of three phases: carbon fixation, reduction reactions, and regeneration of the starting molecule-ribulose 1,5-bisphosphate (RuBP).

1. Carbon fixation: CO2 bounds to acceptor molecule, ribulose-1,5-bisphosphate (RuBP) and forms six-carbon compound that splits into two molecules of 3-phosphoglyceric acid (3-PGA). This reaction is catalyzed by the enzyme RuBP carboxylase/oxygenase, or rubisco.

2.  Reduction: 3-PGA molecules are converted into glyceraldehyde-3-phosphate (G3P). ATP and NADPH are used for converting and during this stage NADPH donates electrons (reduces) to a three-carbon intermediate to make G3P. 

3.    Regeneration: G3P molecules are used to make glucose, or are recycled to regenerate the RuBP acceptor. Regeneration requires ATP. 

Three turns of the Calvin cycle are needed to make one G3P molecule. A G3P molecule contains three fixed carbon atoms, so it takes two G3Ps to build a glucose, which contains six carbons. To produce one molecule of glucose, it would take six turns of the cycle.

Mantle convection  is the slow  creepingmotion of earth's solid silicate  mantle  caused by  convection  currents carrying  heat from the interior  to the planet's surface.[1][2]  the earth's surface  lithosphere, which rides atop the  asthenosphere  (the two components of the  upper mantle), is divided into a number of  plates  that are continuously being created and consumed at their opposite  plate boundaries. accretion occurs as mantle is added to the growing edges of a plate, associated with  seafloor spreading. this hot added material cools down by  conduction  and  convection  of heat. at the consumption edges of the plate, the material has thermally contracted to become dense, and it sinks under its own weight in the process of  subduction  usually at an  ocean trench.[3]this subducted material sinks through the earth's interior. some subducted material appears to reach the lower mantle,[4]  while in other regions, this material is impeded from sinking further, possibly due to a phase transition from  spinel  to  silicate perovskiteand  magnesiowustite, an  endothermic reaction.[5]the subducted oceanic crust triggers  volcanism, although the basic mechanisms are varied. volcanism may occur due to processes that add buoyancy to partially melted mantle causing an upward flow due to a decrease in density of the partial melt.secondary forms of convection that may result in surface volcanism are postulated to occur as a consequence of intraplate extension[6]  and  mantle plumes.[7]it is because the mantle can convect that the  tectonic plates  are able to move around the earth's surface.[8]mantle convection seems to have been much more active during the  hadean  period, resulting in gravitational sorting of heavier molten  iron, and  nickel  elements and  sulphides  in the core, and lighter  silicate minerals  in the  mantle.

Ithink its c hope it : )