Free Course Image Biology foundations

Free online course Biology foundations

Duration of the online course: 1 hours and 33 minutes

4.5

StarStarStarStarHalf star

(6)

Build strong biology skills fast with a free online course—master scientific thinking, cells’ chemistry, and pH fundamentals to study smarter.

In this free course, learn about

  • Overview of biology and core characteristics of life studied in the course
  • How the scientific method works: questions, hypotheses, testing, and conclusions
  • What makes a strong hypothesis: testable, falsifiable, and evidence-based
  • Using data to justify experimental claims and interpret experimental results
  • Principles of experimental design: controls, variables, replication, and reducing bias
  • Atomic structure basics: elements, atoms, and compounds
  • What defines an element/atom: number of protons (atomic number)
  • Carbohydrates: structure, roles, and typical C:H:O ratio (~1:2:1)
  • Proteins and amino acids: amino acids as the building blocks of proteins
  • Lipids: properties and why they are mostly insoluble in water
  • Nucleic acids and nucleotides: sugar, phosphate, and nitrogenous base components
  • Vitamins vs minerals in nutrition: organic vs inorganic micronutrients
  • Water’s life-enabling properties: hydrogen bonding and solvent behavior
  • pH basics: what the pH scale measures and acids vs bases

About the free online course

If biology has ever felt like a blur of unfamiliar terms, this course helps you build a clear foundation you can trust. You will connect big-picture ideas about life with the practical tools scientists use to investigate it, so the subject stops feeling like memorization and starts feeling like understanding. Designed for school-level learning, it supports you in developing confidence for homework, exams, and future science classes.

You begin by exploring what biology studies and how scientists turn questions into testable investigations. By focusing on the scientific method, hypotheses, and evidence-based reasoning, you learn how to judge claims using data instead of guesswork. You will also strengthen your ability to think about variables, controls, and fairness in testing, which is essential not only in biology labs but in everyday decision-making where evidence matters.

From there, the course bridges biology with the chemistry that powers living systems. You will make sense of elements and atoms, then move into the molecules of life: carbohydrates, proteins, lipids, and nucleic acids. Rather than treating these as separate definitions, you will see how their structures relate to their roles in organisms—how building blocks like amino acids and nucleotides help explain everything from energy use to heredity. You will also learn the difference between vitamins and minerals and why that distinction matters in human nutrition.

Finally, you focus on water and the chemical environment of cells. You will understand hydrogen bonding, why water is such an effective solvent, and how these properties make life as we know it possible. You will also learn what pH measures and why changes in acidity can affect biological systems. Along the way, practice questions help you check your understanding, spot gaps early, and study more efficiently. By the end, you will have a solid, connected framework that makes the rest of biology far easier to learn.

Course content

  • Video class: Biology overview 04m
  • Exercise: What fundamental characteristic of life is highlighted as a topic that will be studied in the Khan Academy's Biology section?
  • Video class: The scientific method 11m
  • Exercise: What is a key aspect of a hypothesis in the scientific method?
  • Video class: Data to justify experimental claims examples | High school biology | Khan Academy 05m
  • Exercise: Based on the biological principle that muscles perform better when adequately warmed up, what is the most likely reason trial two supported the student's claim better than trial one in the given experiment?
  • Video class: Introduction to experimental design | High school biology | Khan Academy 09m
  • Exercise: Which of the following is NOT a fundamental principle of a well-designed scientific experiment?
  • Video class: Elements and atoms | Atoms, compounds, and ions | Chemistry | Khan Academy 13m
  • Exercise: The most basic unit of an element is the:
  • Exercise: What defines the element of an atom?
  • Video class: Introduction to carbohydrates | Biology foundations | High school biology | Khan Academy 04m
  • Exercise: Which of the following best describes the elemental composition ratio of carbohydrates similar to that of water?
  • Video class: Introduction to proteins and amino acids | Biology foundations | High school biology | Khan Academy 05m
  • Exercise: What are amino acids commonly referred to in the context of proteins?
  • Video class: Introduction to lipids | Biology foundations | High school biology | Khan Academy 05m
  • Exercise: Which of the following statements best describes the solubility of lipids in water?
  • Video class: Introduction to nucleic acids and nucleotides | High school biology | Khan Academy 05m
  • Exercise: Which of the following is NOT a component of a nucleotide?
  • Video class: Introduction to vitamins and minerals | Biology foundations | High school biology | Khan Academy 06m
  • Exercise: What distinguishes vitamins from minerals in the context of human nutrition?
  • Video class: Hydrogen bonding in water | Water, acids, and bases | Biology | Khan Academy 06m
  • Exercise: Why is water considered essential to life as we know it?
  • Video class: Water as a solvent | Water, acids, and bases | Biology | Khan Academy 09m
  • Exercise: Which of the following explanations best describes why water is considered a good solvent?
  • Video class: Introduction to pH | Biology foundations | High school biology | Khan Academy 05m
  • Exercise: What does the pH Scale Measure?

This free course includes:

Icon for learning via the audio course

1 hours and 33 minutes of online video course

Icon for the digital course completion certificate

Digital certificate of course completion (Free)

Icon for exercises to practice what you've learned

Exercises to train your knowledge

Icon for courses that are 100% free from start to finish

100% free, from content to certificate

What does the pH scale measure in biology?

The pH scale measures how acidic or basic a solution is, based on its hydrogen ion concentration.

Why is water a good solvent for living organisms?

Water is polar, so it can surround and dissolve many ionic and polar substances needed for biological reactions.

What are the main components of a nucleotide?

A nucleotide contains a sugar, a phosphate group, and a nitrogenous base.

Ready to get started?Download the app and get started today.

Install the app now

to access the course
Icon representing technology and business courses

Over 5,000 free courses

Programming, English, Digital Marketing and much more! Learn whatever you want, for free.

Calendar icon with target representing study planning

Study plan with AI

Our app's Artificial Intelligence can create a study schedule for the course you choose.

Professional icon representing career and business

From zero to professional success

Improve your resume with our free Certificate and then use our Artificial Intelligence to find your dream job.

You can also use the QR Code or the links below.

QR Code - Download Cursa - Online Courses

Course comments: Biology foundations

BS

basiru Suleiman

StarStar

biology

FJ

fatima jahan

StarStarStarStarStar

Amazing teaching style learned so much , would recommend it to other students your notes were great.

FH

Fatima Hussain

StarStarStarStarStar

fantastic test were fair without being easy

JS

Jade Scott

StarStarStarStarStar

I am grade 4

FH

Fatima Hussain

StarStarStarStarStar

great app for students

More free courses at Biology

Free Ebook + Audiobooks! Learn by listening or reading!