Science Classes in High School: A Complete Grade-by-Grade Guide

High school science requirements vary by state, but the underlying sequence of courses is remarkably consistent across the country. Most students move through Biology, Chemistry, and Physics during their four years, with AP options available at each stage for students pursuing STEM or health science paths. Understanding the full high school science sequence, what each course requires, and how to align course selection with college goals helps parents and students make smarter decisions about the academic path ahead.

Students who struggle in a high school science course, whether Biology, Chemistry, or Physics, often need subject-specific support that goes beyond what the classroom provides. Blackmon Tutoring's tutoring services provide certified science tutoring across all high school science courses for students in 9th through 12th grade, online nationwide and in-person in our service states.

What Science Classes Are Required in High School?

Most states require three to four science credits for high school graduation. The specific courses required vary by state, but the most common requirement structure looks like this:

State requirements set the floor, not the ceiling. Students applying to selective colleges are expected to take more than the minimum, typically four years of science with at least two laboratory science courses. Students targeting STEM or health science majors should plan for three to four AP science courses across their high school career.

Science requirements vary by state and school district. Confirm your child's specific graduation requirements with their school counselor.

9th Grade Science: Biology

Biology is the most common 9th grade science course and serves as the foundation for all subsequent life science and health science coursework. Students who develop a strong Biology foundation are significantly better prepared for AP Biology and for college-level Biology in pre-med and life science programs.

Key Biology Topics

• Cell structure and function, cell division, and cellular respiration
• Genetics and heredity, Punnett squares, and DNA structure and function
• Evolution by natural selection and evidence for evolutionary relationships
• Ecology and ecosystem dynamics
• Anatomy and physiology of major body systems

Do You Have to Take Biology in High School?

In most states, Biology is a required course for all high school students. It is typically the first science course in the standard sequence and must be passed for graduation. Students who fail or significantly struggle in Biology should seek targeted support rather than hoping to pass on effort alone, because Biology concepts appear in Chemistry and AP Biology later.

AP Biology

AP Biology is available to students who have completed standard Biology and typically taken Chemistry as well. The course covers Biology at a significantly deeper level than the standard course and requires strong scientific reasoning and data analysis skills. AP Biology is one of the most important courses for students pursuing pre-med, bioengineering, or life science majors.

10th Grade Science: Chemistry

Chemistry is the science course that most commonly requires outside tutoring support because it combines conceptual understanding with mathematical problem solving in ways that genuinely challenge many students. Understanding chemistry builds directly on algebra and basic physics principles.

Key Chemistry Topics

• Atomic structure and the periodic table
• Chemical bonding, molecular structure, and VSEPR theory
• Stoichiometry and molar relationships
• Gas laws and thermodynamics
• Acid-base chemistry and solution equilibrium

Do You Have to Take Chemistry in High School?

Chemistry is required for graduation in most states under the standard or advanced diploma track. Students on a minimum diploma track may be able to substitute another lab science, but most college-bound students are expected to complete Chemistry. Students planning to attend any four-year college or university should take Chemistry regardless of whether it is strictly required for their diploma.

AP Chemistry

AP Chemistry is one of the most demanding AP science courses and is considered a significant differentiator for students applying to highly selective colleges in STEM or pre-med fields. It requires completion of standard Chemistry and strong algebra and mathematical reasoning skills.

11th Grade Science: Physics

Physics is typically the third course in the standard science sequence and is where many students encounter scientific reasoning in its most mathematical form. Physics requires applying algebra and sometimes trigonometry to understand motion, forces, energy, and waves.

Key Physics Topics

• Kinematics: describing motion using position, velocity, and acceleration
• Forces and Newton's Laws of Motion
• Energy, work, and conservation laws
• Waves and sound
• Electricity and magnetism

What Comes After Biology and Chemistry?

After completing Biology and Chemistry, most students take Physics to complete the standard three-course science sequence. Students pursuing STEM paths often take AP Physics alongside or after standard Physics. Students who complete the standard sequence early may take AP Environmental Science, AP Psychology, Anatomy and Physiology, or an elective science as their fourth year course.

AP Physics

AP Physics is offered in multiple versions: AP Physics 1 (algebra-based), AP Physics 2 (algebra-based, more advanced), AP Physics C: Mechanics, and AP Physics C: Electricity and Magnetism (both calculus-based). Students pursuing engineering or physics majors in college should take AP Physics C. Students who want AP credit without calculus prerequisites can take AP Physics 1.

12th Grade Science Options

Students who have completed the standard Biology, Chemistry, Physics sequence in 9th through 11th grade have significant flexibility in 12th grade science. Here are the most common options:

For students planning their high school course sequence with college in mind, Blackmon Tutoring's college consulting program helps families build an academic plan that aligns science courses, AP selections, and extracurricular choices with specific college and major goals.

Types of Science Classes in High School: Electives and Specialized Courses

Beyond the standard Biology, Chemistry, Physics sequence, many high schools offer specialized science electives that allow students to explore specific areas of interest or begin building expertise relevant to their intended major.

• Forensic Science: applies Chemistry, Biology, and Physics principles to crime scene investigation contexts. Engaging and accessible for students who are interested in science but not planning a STEM major.
• Astronomy: covers the solar system, stars, galaxies, and cosmology. Strong math component. Good for students interested in physics or space science.
• Marine Biology or Environmental Science: explores ecological systems and environmental relationships. Good preparation for environmental science or biology majors.
• Biotechnology: applies molecular biology techniques to real-world problems. Excellent preparation for bioengineering, genetics, or health science majors.
• Anatomy and Physiology: covers human body systems in depth. Direct preparation for nursing, pre-med, physical therapy, and other health science paths.

Aligning Science Courses With College Major Goals

Science course selection in high school has direct implications for college major options and college application strength. Here is how to align the two:

Course availability varies by school. Confirm which AP and elective science options are offered at your child's high school before building a multi-year plan.

Conclusion

High school science courses build on each other in a logical sequence that starts with Biology, moves through Chemistry and Physics, and opens into specialized and AP options in junior and senior year. Understanding this sequence and how to align it with college goals helps students and parents make smarter decisions about which courses to take and when.

Students who struggle in any course along the sequence benefit most from targeted subject-specific support that addresses the actual conceptual gaps rather than generic tutoring.

Blackmon Tutoring provides certified science tutoring across the full high school science sequence, from standard Biology and Chemistry through AP sciences. Visit our tutoring services page to get matched with the right science tutor for your child's current course and goals.