Maybe a better question would be What is masculinity and what is femininity?

Masculine and feminine are largely social constructs. What one culture considers masculine or feminine may not be considered as such by a different culture.

1. Each sperm has either an X or a Y chromosome in it. All eggs have an X chromosome. When sperm fertilizes an egg, its X or Y chromosome combines with the X chromosome of the egg. A person with XX chromosomes usually has female sex and reproductive organs, and is therefore usually assigned biologically female.
Note: Previous studies have found behavioral differences between men and women. For example, women may have better verbal memory and social cognition, whereas men may have better motor and spatial skills, on average.
Healthy relationships involve honesty, trust, respect and open communication between partners and they take effort and compromise from both people. There is no imbalance of power. Partners respect each other's independence, can make their own decisions without fear of retribution or retaliation, and share decisions.

2. Anatomy and physiology are two of the most basic terms and areas of study in the life sciences. Anatomy refers to the internal and external structures of the body and their physical relationships, whereas physiology refers to the study of the functions of those structures.
Research suggests students find physiology content more difficult to learn than anatomy (14, 22), but few studies have investigated the drivers behind student difficulty when learning physiology.

The whole is greater than the sum of his/her parts. Mentally, emotionally, and physically.

XD

i think personally it has to do with anatomy

One gets married for money.

The other gets married if they can afford to pay the bills.

Gender roles are largely t a u g h t .
Wearing pink and wearing blue,
Long nails and short nails,
Skirts and shirts.

There's no reliable way to really know if guys and girls would think and act differently if they were treated the same way growing up,
or if the difference between them is only anatomical and has nothing to do with an inherent "feminine" nature in girls or a natural "masculine" attitude in boys.

Well for one thing men only know the colors ROYGBIV, black, gray, brown, and white.

some people say it is what that person defines themselves as, and others say it is your anatomy. i dont want to get into it now, because i have gotten into some pretty negative decisions about it in the past, but i believe that there are two genders, that are based on your anatomy.