What part of the avian digestive system is most closely related to the stomach, where HCL and other gastric juices do a large portion of breaking down the food?

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.

not always but somethings can be reproduced in a laboratory.

can i have a list of the items?