Introduction to Molecular and Cellular Biology

Saylor University 36 hours English Free course 4.6 (350+ ratings)

Free course

Course Description

Life is complex, but it all starts at the smallest scale: molecules and cells. This course takes you on a journey into the microscopic world that powers every living thing. You'll learn how molecules like DNA, proteins, and carbohydrates work together inside cells to create the incredible diversity of life around us.

BIO101: Introduction to Molecular and Cellular Biology is a full college-level course offered free by Saylor University. It's designed for students who want to understand the foundational biological processes that affect our health, environment, and daily lives. The course covers everything from the structure of atoms to the inner workings of cells, and how environmental factors influence molecular and cellular behavior.

This completely free, self-paced course takes about 36 hours to complete and is equivalent to 3.6 Continuing Education Units (CEUs). You'll work through readings, videos, quizzes, and assignments. Upon completion, you can earn a free certificate. Even better, the course is recommended for college credit by the American Council on Education (ACE), meaning you may be able to transfer it to a degree program.

Whether you're aiming for a career in medicine, research, biotechnology, agriculture, or education, or you just want to understand the science behind news about health and the environment, this course gives you a solid foundation.

Course Provider

Provider: Saylor University, a nonprofit initiative offering free, open online courses to learners worldwide. Saylor courses are designed to match the rigor of traditional university classes.

Platform: Saylor's learning platform (learn.saylor.org) – fully online, self-paced, with a clean, easy-to-navigate interface.

Accreditation: Saylor Academy is a recognized provider of continuing education and ACE Credit-recommended courses. This course has been evaluated by the American Council on Education and is recommended for 3 semester hours of college credit in introductory biology (without lab). Many colleges accept ACE-recommended credits. The free certificate is also widely recognized as evidence of learning.

Course Syllabus (Core Units)

Unit 1: Introduction to Biology and the Scientific Method – What is life? The scientific method, experimental design, and basic chemistry of life.

Unit 2: The Chemical Foundation of Life – Atoms, molecules, chemical bonds, water, and the importance of carbon. Introduction to organic molecules (carbohydrates, lipids, proteins, nucleic acids).

Unit 3: Cell Structure and Function – Prokaryotic vs eukaryotic cells, organelles (nucleus, mitochondria, ER, Golgi, etc.), and the endomembrane system.

Unit 4: Cell Membranes and Transport – The fluid mosaic model, diffusion, osmosis, active transport, endocytosis, and exocytosis.

Unit 5: Metabolism and Enzymes – Energy in living systems, ATP, enzyme function, factors affecting enzymes, metabolic pathways.

Unit 6: Cellular Respiration – Glycolysis, the Krebs cycle, electron transport chain, oxidative phosphorylation, and fermentation.

Unit 7: Photosynthesis – Light-dependent reactions, the Calvin cycle, and the importance of photosynthesis to life on Earth.

Unit 8: Cell Communication and Signaling – Signal transduction pathways, receptors, second messengers, and cellular responses.

Unit 9: The Cell Cycle and Mitosis – Interphase, mitotic phases, cytokinesis, and control of the cell cycle (including cancer).

Unit 10: Meiosis and Sexual Reproduction – Meiosis I and II, crossing over, genetic variation, and comparison with mitosis.

Unit 11: Mendelian Genetics and Inheritance – Mendel's laws, Punnett squares, dominance, segregation, independent assortment, and human genetics.

Unit 12: Molecular Biology – DNA structure and replication, transcription, translation, and the central dogma of molecular biology.

Unit 13: Gene Expression and Regulation – Prokaryotic vs eukaryotic gene regulation, operons, transcription factors, and epigenetics.

Unit 14: Biotechnology and Modern Applications – DNA technology, PCR, gel electrophoresis, CRISPR, and ethical considerations.

Plus a final exam covering all units.

Learning Objectives

Understand the chemical and molecular foundations of life.
Describe the structure and function of prokaryotic and eukaryotic cells.
Explain how cells obtain and use energy through metabolism, respiration, and photosynthesis.
Analyze how cells communicate and respond to their environment.
Understand the cell cycle, mitosis, meiosis, and how genetic information is passed on.
Apply Mendelian genetics to predict inheritance patterns.
Explain DNA replication, gene expression, and protein synthesis.
Discuss modern biotechnologies like CRISPR and their ethical implications.
Prepare for careers in medicine, research, agriculture, education, or industry.
Earn a free certificate and potential college credit.

Course Prerequisites

Academic: This is a college-level introductory course. High school-level biology and basic chemistry are helpful but not strictly required. You should be comfortable with scientific terminology and basic algebra.

Language: English reading proficiency at a college level (the course includes dense textbook chapters and scientific articles).

Technical: A reliable internet connection and a device to access readings, videos, and quizzes. No special software needed.

User Reviews

★★★★★ Jessica M.

"I was skeptical about a free biology course, but this is the real thing. The depth is exactly what I'd expect from a first-year university course. The readings are from real open-access textbooks, and the quizzes forced me to really learn the material. I'm using the ACE credit recommendation to apply to a nursing program. Life-changing."

★★★★☆ David K.

"This course is thorough. It took me about 40 hours to finish. The molecular biology unit was challenging but well explained. The free certificate is a nice bonus. My only complaint is that some of the videos are a bit dated, but the science is solid. Highly recommended for anyone needing a biology prerequisite."

★★★★★ Priya S. – April 30, 2026

"As a high school student wanting to get ahead, this course was perfect. The structure is clear, and you can go at your own pace. I especially loved the unit on biotechnology and CRISPR. I earned my free certificate and am using it to demonstrate my interest in biology for college applications. Thank you Saylor!"

Based on 350+ ratings on Saylor and Class Central.

Free courses groups Join Facebook Group Join Telegram Channel

💡 Final Thoughts

If you need a solid, college-level biology course and you're on a budget, this is one of the best free options available. Saylor's BIO101 is rigorous, comprehensive, and respected enough to be recommended for college credit by the American Council on Education. You'll learn everything from atoms to ecosystems, but with a focus on the molecular and cellular level. The self-paced format means you can fit it around your schedule, and the free certificate is a legitimate credential. Whether you're pursuing a career in healthcare, research, or just want to be scientifically literate, this course will give you a deep understanding of the machinery of life.

Introduction to Molecular and Cellular Biology – FAQ

Is this course really free?

Yes, completely free. Saylor University offers all course materials, quizzes, and the final exam at no cost. You can also download a free certificate upon completion. There is no paid upgrade.

Can I really get college credit for a free course?

This course has been recommended for 3 semester hours of college credit by the American Council on Education (ACE). Many colleges accept ACE-recommended credits, but you should check with your institution. There is a small fee if you choose to claim ACE credit (separate from Saylor), but the Saylor course itself is free.

How long will the course take me?

The course is designed to take approximately 36 hours of study time. Since it's self-paced, you can finish faster or slower depending on your background and schedule. Most learners complete it in 4-8 weeks.

Do I need a textbook?

No. All readings are provided for free as open educational resources (OER) within the course. You don't need to buy anything.

What kind of certificate do I get?

Upon passing the final exam (70% or higher), you can download a free certificate of completion from Saylor Academy. It includes your name, course name, and completion date. It's a PDF that you can share on LinkedIn or with employers.

Is this course lab science?

No, this is a lecture-only course. It does not include a laboratory component. For most transfer purposes, it counts as introductory biology without lab. Some majors may require a separate lab course.