Two Xchromosomes and a blue uniform may not be enough.
而两条X染色体和一套蓝色制服未必就足够了。
2
There are two chromosomes (chromosome X and chromosome y) involved in this process, and a combination of these chromosomes will determine the gender of the baby.
有两条染色体(染色体x和染色体y)参与到这个过程中,这些染色体的组合将会决定婴儿的性别。
3
However, in 2000, scientists announced that the X and Y chromosomes were once a pair of identical twins.