The distinction of a man from a woman has many implications scientifically. The biological basis for sexuality in human organism is so basic that all boils down to the presence or absence of the so-called sex-determining region Y (SRY) protein in one’s DNA. But there’s much more, especially when one wishes to be serious with his Christian Faith!
One of my students pointed out that SRY is an important protein that determines one’s sexuality biologically. Indeed, this protein is responsible for the initiation of male sex determination in humans.  Sometimes however, the expression of this protein up to the phenotypic level (those characteristics obvious to an adult human organism) is not present due to some abnormal events. These atypical events are named syndromes (e.g. Swyer syndrome) generally referred to as gonadal dysgenesis. In short, there are cases that natural potentialities are not expressed due to irregularities in the system.
Philosophically, the discussion should go deep into our understanding of reality and truth, like we would discuss about matter and form in things. For example, when we talk about things (beings), we must first address its nature (esse). Talking about spiritual things in terms of physical attributes therefore becomes a kind of analogical (e.g. strong will, odorous love, attractive psyche). Describing physical things will then become more literal (e.g. red lips, blue sky). Pure spiritual (non-physical) things are always the same such that numerically, there is only one one-meter radius circle but there are numerically many physical representation of the same.
Thus, the choice of the image in this post. Maleness and femaleness is a physical aspect of the human beings. The physical body is the source and cause of variations between human beings. The non-physical aspect we refer to as “soul” (or human form) of every human being has equal dignity in so far as their humanity is concerned. Dignity is determined by one’s nature, not by characteristics (human character). Character can only either magnify that dignity or conceal such inherent dignity.
I am not very surprised to read about the his/her pronoun in the English translation of the Bible recently on the debate about feminism and the “issue” of the pronoun translations. It turns out that inclusivity can either be vertical or horizontal. The philosophical underpinnings of the usage of the pronoun He or terms such as Father and Son in reference to the persons of God and his divine nature is immense! Here’s a quote:
If God’s self-revelation is perverted, then both our understanding of God and ourselves is changed, as well. When God is named Mother (and a name speaks of what is of the essence of a thing), God is turned into an earth goddess of which we are but a part (panentheism). 
Indeed, motherhood is more appropriately related to the materiality of something. As one’s idea is also known as the same’s “brainchild”.
 Wikipedia contributors. “Testis-determining factor.” Wikipedia, The Free Encyclopedia. Web. 20 Feb 2017.
 “Bible Versions and Commentaries.” United States Conference of Catholic Bishops (USCCB). Web 20 Feb 2017.