This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Abdomen and pelvis, Subject name: Anatomy
Spermatazoa with which chromosome is faster? 
Select and explain. 
A. X chromosome, B. Y chromosome, C. Both same, D. None
B: Y chromosome
Answer: B: Y chromosome 
Explanation: The spermatozoa bearing the Y chromosome swim faster than the spermatozoa bearing X chromosome.