The research in this dissertation focuses on ways to improve the teaching and learning of science in a suburban junior high school on Long Island, New York. The study is my attempt to find ways to achieve parity in my classroom in terms of success in science. I was specifically looking for ways to encourage Black female students in my classroom and in other classrooms to continue their science education into the upper grades. The participants were the 27 students in the class, a friend of one of the students, and I, as the teacher-researcher. In order to examine the ways in which structure mediates the social and historical contexts of experiences in relation to teacher and student practices in the classroom, I used collaborative research; autobiographical reflection; the sociology of emotions; immigration, racialization, and ethnicity, and cogenerative dialogues ("cogens") as tools. Cogenerative dialogues are a way for students and teachers to accept shared responsibility for teaching and learning. This study is of importance because of my school's very diverse student body. The school has a large minority population and therefore shares many of the characteristics of urban schools. In my study I look at why there are so few Black female students in the advanced science courses offered by our district and how this problem can be addressed. I used a variety of qualitative approaches including critical ethnography and micro analysis to study the teaching and learning of science. In addition to the usual observational, methodological, and theoretical field notes, I videotaped and audiotaped lessons and had discussions with students and teachers, one-on-one and in groups. In the first year the cogenerative group consisted of two Black female students. In the second year of the study there were four Black and one White-Hispanic female students in the cogen group. In my research I studied the interactions of the students between lessons and during laboratory activities as well as the cogens themselves in order to get the data needed to identify the role of science cogens in the learning and teaching of science. The students both in my cogen and in my science class collaborated with me as we worked to create new culture through conversations. I also used cogens to examine the influence of immigration, race, ethnicity, and gender in my science class. The students in the cogen were native-born children of immigrants, known as the second generation and/or 1.5 generation. In the first year one of these students was the daughter of Jamaican-born parents and the other native Black. The students in the second year included one each of Haitian and Jamaican descent, one with Dominican parents, and two native Blacks. Interestingly enough, if I had not conducted the cogenerative dialogues, I might never have become aware of their ethnicities. The cogens helped me to become a better teacher by allowing me to understand what racialization was and how it impacted students as well as teachers. The cogens helped students voice their opinions in a manner and in a place that supported their understanding of both the similarities and differences among students in the class in addition to contradictions in their science class as well as in other nested fields. Contradictions are differences between people and groups that arise as a normal part of social life in the classroom (and elsewhere, of course), and I looked for ways to retain these differences as we learned to deal with them. I looked especially for contradictions that were evident between the larger culture of the school and that of the students in the cogen. I studied the dialectical relationship between agency and structure in my science class and within the cogenerative dialogue group. I found that as students gained agency, they were more successful in obtaining entry into accelerated science classes and succeeded in those classes. I found that some marginalized students were shut down in their classrooms. During the common planning time within the science department, we discussed the lack of minority students in our advanced science classes. I introduced the idea of cogens and described how they could encourage more students to become involved in the process of learning. Although my colleagues did not institute cogens with their students, they did listen to the ideas about culturally relevant teaching which I communicated, and I was told by some of my colleagues that they were trying to address the cultural mismatch found in their classrooms. The science faculty and I spoke to administrative personnel, and they saw how their goals and ours were aligned. Soon, all stakeholders were on board: my chairperson, the science department, and the administration. (Abstract shortened by UMI.) [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]