Science

Science — Grade 9

American Curriculum · Ages 14-15

Ninth grade science is most commonly Biology or Physical Science, depending on the district's course sequence. Biology covers cell structure and transport, biochemistry, cellular energy, DNA and protein synthesis, genetics, evolution and ecology.

Where the course is Physical Science, it covers atomic structure, the periodic table, chemical bonding and reactions, motion, forces, energy and waves. Either way, the emphasis moves toward quantitative work, laboratory technique and writing conclusions supported by data.

Key topics covered

• Cell Biology — Cell structure, membrane transport, and the chemistry of living things.
• Cellular Energy — Photosynthesis and cellular respiration as energy-transforming processes.
• DNA & Protein Synthesis — DNA structure, replication, transcription and translation.
• Genetics — Mendelian inheritance, Punnett squares, pedigrees and genetic disorders.
• Evolution — Natural selection, speciation and evidence for common ancestry.
• Ecology — Population dynamics, energy flow, biogeochemical cycles and human impact.
• Laboratory & Data Skills — Technique, measurement, graphing and evidence-based conclusions.