As long, as there exists two types of genders in this world, bias is likely to be there in most of spheres of life especially education. As we have seen way back in the past men were given more opportunities and exposure to education. Today in most of developed countries education is easily available to both the genders. But it may not be so with under developed countries. Girls are still isolated and associated with domestic chores in the rural areas and villages of developing countries. Poverty is not eradicated fully in such countries. Poor families don't mind investing money for the education of males but do hesitate to do that for the females.
Assuming that both girls and boys are given equal opportunities in education there is still some differences with respect to reactions to them from the society. Many teachers exhibit an unconscious gender bias which is strongly linked to their cultural background. Gender bias could occur when the teacher who is of one gender is influenced by the behaviours, attitude of other genders towards them. For example, boys are considered to be boisterous and mischief makers; while girls are supposed to more docile, studious and patient. When girls start misbehaving in class and show characteristics of boys it is not tolerated by the teachers and they think it is bad behaviour.
Similarly science and intellect is associated more with boys than girls. Records also say that the percentage of lady engineers is hardly 30% of the total work force. Also the tougher jobs and questions are always given to the boys. They are forced to accept challenges and perform. While though females have opportunities to perform it is not thrust on them. Hence the women folk need to put more effort to stay on top.
In many cases girls are used to civilize the boys. If there is a mischief boy in class, he is made to sit next to a girl to tone him down. Thus the gender bias is sometimes used to nullify the negative effects of relationships. Also it seen that tough jobs like piloting, sea diving or mountaineering is typically a man's domain. You find very few ladies taking to such professions. It is mainly because society does not think they have the relevant capabilities and always associate soft, sober roles for women.
Thus the mindset of the majority of people needs to be changed to see no gender bias. Whether it can happen or not, is a million dollar question.