Abstract
Learning inheritance of traits in grade IX MTs Darul Ulum faces obstacles in the form of abstraction of the concepts of genes, alleles, genotypes, phenotypes, and crossover processes, while the use of visual media that helps students understand the Punnett Diagram is still limited. This condition causes students to tend to memorize procedures without understanding the relationship between whole genetic concepts. This research aims to develop the learning media of the Punnett Diagram and determine the level of validity, practicality, and effectiveness in the inheritance material. The research uses the Research and Development method with the ADDIE model, which includes the stages of analysis, design, development, implementation, and evaluation. The research subjects consist of material experts, media experts, science teachers, and 29 students of grade IX MTs Darul Ulum. Data were collected through observation, interviews, documentation, questionnaires, as well as pretest and posttest. Validity and practicality data were analyzed descriptively using percentages, while effectiveness was analyzed using N-Gain. The results showed that the media obtained an average validity of 86.00 percent with a very valid category. The teacher's response reached 88.40 percent, and the student's response was 85.80 percent, both in the very practical category. The average score of the students increased from 58.62 in the pretest to 81.38 in the posttest with an N-Gain of 0.55 in the medium category. It is concluded that the Punnett Diagram media is valid, practical, and effective as an alternative for science learning.