The Y chromosome was discovered by Nettie Stevens at Bryn Mawr in 1905.
Only males have the Y chromosome. In humans, the Y chromosome represents only 1% of the total DNA in a male's cells.The Y chromosome contains 200 genes.
Male smokers have between 1.5 and 2 times the risks of developing lung cancer than do females.
Males are also susceptible to defects in the X chromosome since males have only one X chromosome..