This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology, Subject name: Pediatrics
Gonads to testes differentiation 
Select and explain. 
A. SRY gene, B. WNT-4 gene, C. DAXI gene, D. None
A: SRY gene
Answer: A: SRY gene 
Explanation: SRY sex determining region on the Y chromosome . Reference: OP Ghai,essential paediatrics ,8 th edition,page no 537,fig 17.20