In this article we seek a better understanding of the specificities of the gender gap, regarding the reality of women in the different disciplines contained in STEM within Latin America. Specifically, we analyze and compare the situation of women in the Institutes of Mathematics, Ecology and Biology, belonging to the National Autonomous University of Mexico (UNAM). In this novel study, we contribute to deepen in how the phenomena of horizontal and vertical segregation are combined with symbolic and structural obstacles, as well as economic-labor precariousness, within the framework of gender norms. We also analyze the points in common regarding the situation in the Global North. We consider that these facts are fundamental to understand how gender stereotypes are perpetuated in the production of knowledge, and what are the values implied in gender norms that explain the exclusion, and self-exclusion, of women in certain disciplines and statuses. Related to this, we inquired into the relationship between these values and the cultural capital represented in each of the disciplines mentioned and found that the knowledge areas that currently represent the highest cultural capital pose symbolic obstacles for women. Conversely, those areas that less strongly embody values associated with masculinity, and therefore have less cultural capital, present mainly structural obstacles for women.