Title: Diseño de un unidad didáctica como estrategia para abordar la enseñanza de la herencia mendeliana en estudiantes de grado noveno.
Abstract: In this paper the theoretical foundations of a teaching unit aimed at ninth grade students, related to the concept of Mendelian inheritance, which seeks address the teaching of genetics in a more dynamic way., as this is considered basic science for understanding many biological phenomena, for it raised to 3 targets) achieved through a teaching unit understanding of concepts such as: homozygous, heterozygous, dominant, recessive allele, gene; b) promote learning through solving problematic situations that allow you to apply both biological concepts as some basic functions of mathematics and c) allow students to recognize different genetic traits, not only in terms of illness but as to morphological aspects of diversity on earth.To carry it out, it was decided to use the proposed by Garcia in 1997 and considers it important to include the context and imaginary students to achieve the construction of a school knowledge school research approach.This research was conducted for 7 sessions in which it was found that most students made an appropriation of knowledge because the unit in addition to providing the social context and territory manages learning based on action or cooperation (ABA), which allows them to wake their knowledge and emotions through inquiry and disclosure with peers.