Ask a Teacher

Search



I've come across a term 'Ornithine cycle'. What is it?? is it some thing related to ornithology (study of birds). 2) what is term used for the determination of age of trees?? 3) What is abberal chromosomal compliment , apoptosis , porins , globoid , emerson effect ? 4) In tne evolution of animals a heart to pump the blood is found for the fist time in which organism( annelids or arthropoda)?

The urea cycle (also known as the ornithine cycle) is a cycle of biochemical reactions occurring in many animals that produces urea ((NH2)2CO) fromammonia (NH3). This cycle was the first metabolic cycle discovered (Hans Krebs and Kurt Henseleit, 1932), five years before the discovery of the TCA cycle. In mammals, the urea cycle takes place primarily in the liver, and to a lesser extent in the kidney.
Dendrochronology or tree-ring dating is the scientific method of dating based on the analysis of patterns of tree-rings. Dendrochronology can date the time at which tree rings were formed, in many types of wood, to the exact calendar year. 


comments powered by Disqus