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: Biochemistry
What is the basis of soing X-chromosome bearing and Y-chromosome bearing sperm? 
Select and explain. 
A. X-chromosome has 2.8% more DNA, B. Y-chromosome has 2.8% more DNA, C. X-chromosome has 0.28% more DNA, D. Y-chromosome has 0.28% more DNA
A: X-chromosome has 2.8% more DNA
Answer: A: X-chromosome has 2.8% more DNA 
Explanation: Ans. is 'a' i.e.,X-chromosome has 2.8% more DNAA sperm-soing technology (the microso method) is the most effective procedure yet devised at separating X-bearing and Y-bearing sperm.X sperm have only 2.8% more DNA than those carrying a Y chromosome, fluorescent dye that attaches to DNA and glows under laser light in sperm soer then separates the sperm, sending X sperm down one tube and Y sperm into another.The soed sperm can then be placed in the woman's uterus (aificial insemination) or used for in vitro feilization.