Which is common to both photosynthesis and respiration?
a)nadh is produced by krebs cycle. b)chemical energy is produced in the form of atp. c)two atp are formed by the process of glycolysis. d)glyceraldehyde-3 phosphate is produced by calvin cycle.

B. Chemical energy is produced in the form of ATP.

In photosynthesis photophosphorylation takes place to make ATP in which light energy is converted into chemical energy in the form of ATP. Also in aerobic respiration 2 ATP are produced in glycolysis, 2 in Kreb's cycle and 34 in electron transport system utilizing glucose as a substrate. Therefore energy from food (glucose) is converted into chemical energy in the form of ATP.

the nitrogen cycle provides nitrogen to the ecosystem from the atmosphere, ground and oceans. nitrogen is an important component of complex molecules such as amino acids and nucleotides, which lead to the creation of proteins and dna, the building blocks of all life. plants absorb nitrogen in the form of ammonium, nitrate ion and, on rare occasions, as amino acids. animals receive nitrogen necessary for biological processes from feeding on living or dead organic matter.