EFFECTS OF IMPROVISED AND STANDARD INSTRUCTIONAL MATERIALS ON ACADEMIC ACHIEVEMENT OF SECONDARY SCHOOL STUDENTS IN BIOLOGY. JOURNAL OF SCIENCE EDUCATION AND RESEARCH, [S. l.], v. 3, n. 1, p. 13–30, 2025. Disponível em: https://jserpublications.org/index.php/jser/article/view/13. Acesso em: 26 oct. 2025.