And according to the World Health Organization, "Sex refers to the biological and physiological characteristics that define men and women. Gender refers to the socially constructed roles, behaviors, activities, and attributes that a given society considers appropriate for men and women."
Sex refers to the biological and physiological characteristics, while gender refers to behaviors, roles, expectations, and activities in society.
Sex refers to male or female, while gender refers to masculine or feminine.
The differences in the sexes do not vary throughout the world, but differences in gender do.
Here are some examples of characteristics related to sex:
Females have a vagina, men don't
Males have a penis, women don't
Male newborns tend to weigh more than female newborns
Females can breastfeed their babies, males can't
Males have deeper voices than females
Females can get pregnant, males can't
Males have testicles and females have ovaries
Here are some examples of characteristics related to gender:
Women tend to do more of the housework than their spouses do
A higher percentage of US doctors are women, compared to Egypt
Nursing is often seen as a woman's job, although many men enter the profession
In some countries women have to cover their heads when they go outside the house
120 years ago women were not allowed to vote in elections
Another way of putting it is:
Sex refers to a natural or biological feature.
Gender refers to cultural or learned significance of sex.
According to Medilexicon's medical dictionary:
Sex is "The biologic character or quality that distinguishes male and female from one another as expressed by analysis of the person's gonadal, morphologic (internal and external), chromosomal, and hormonal characteristics."
Gender is "The category to which an individual is assigned by self or others, on the basis of sex."
Sex – Determined by Physical Anatomy, Biological Description