This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
Lipid peroxidation as a cause of ageing and injury of cells is - 
Select and explain. 
A. Free redical theory, B. Apoptosis theory, C. Enzyme cascade theory, D. Cell destruction theory
A: Free redical theory
Answer: A: Free redical theory 
Explanation: Ans. is 'a' i.e., Free redical theory"Free radicals produced during injury or aging cause oxidative decomposition of the lipid.Due to oxidative decomposition organic peroxides are formed after reacting with oxygen (Lipid peroxidation). This reaction is auto-catalytic i.e. new radicals are formed from the peroxide radicals themselves. These radicals cause structural and functional breakdown of endoplasmic reticulum"