Isotoon helps with AP Biology by turning the process you are stuck on, from enzyme activity to gene regulation, into a short animated video you can watch step by step. Pick your unit below, ask the question in your own words, and rewatch it on a spaced schedule before the exam.
Ask your own
AP Biology, unit by unit
Unit 1: Chemistry of Life
Water and its properties, the elements of life, and the structure and function of carbohydrates, lipids, proteins and nucleic acids.
Meiosis and genetic diversity, Mendelian genetics, and patterns that do not follow Mendel, such as linked genes and sex-linked traits.
2D video · 32 seconds
How is meiosis different from mitosis?
Follows one cell down two paths: mitosis makes two identical diploid copies (2n to 2n), while in meiosis homologous chromosomes pair up and cross over, the pairs split in meiosis I, and the cell ends as four genetically unique haploid gametes (2n to n).
DNA and RNA structure, replication, transcription and translation, how genes are switched on and off, mutations, and biotechnology.
3D model · 12 seconds · no sound
How does DNA copy itself?
A recording of a 3D scene of DNA replication: the double helix, its 5′ and 3′ ends marked, turns as helicase and topoisomerase arrive at the replication fork and the parent strands are pulled apart, then primase lands on each separated strand.
How organisms respond to their environment, energy flow through ecosystems, population and community ecology, biodiversity and disruptions to ecosystems.
AP Biology rewards understanding a process well enough to predict what happens when one part changes. So the order matters: first get the idea, then test it on real questions, then keep it.
Then practice with released free-response questions from the College Board. Write the answer, then check it against the scoring guidelines.
Rewatch each video 1, 3, 7, 14 and 30 days after you made it. Your notebook lists them on that schedule, so review in April is short instead of a full relearn.
The AP Biology exam tests more than recall. You are asked to explain a process, read a graph or data table, design or critique an experiment, and predict what happens when part of a system is disrupted. A question about a mutated enzyme or a blocked membrane channel is really asking whether you know the normal process well enough to change one step. Check the College Board course page for the current format.
Where students get stuck
Meiosis versus mitosis, especially what happens to chromosome number and why crossing over matters. Start with meiosis vs mitosis.
Following electrons and protons through respiration and photosynthesis instead of memorizing inputs and outputs.
Replication, transcription and translation running together into one blur. DNA replication is easier as a 3D model you can turn.
Experimental design questions: naming the independent variable, the control and what a result would mean.
What Isotoon does and does not do
Isotoon explains ideas. You type a question and get a short narrated video, with every factual claim checked and its sources listed. It is not a practice-test bank and it does not grade your free-response answers, so pair it with released College Board questions. More on the subject is on the biology page and in exam prep.
Questions
Is Isotoon affiliated with the College Board?
No. AP is a trademark registered by the College Board, which is not affiliated with and does not endorse Isotoon.
Does Isotoon cover all eight AP Biology units?
Yes. You can ask about any idea in any unit in your own words. The questions on this page are examples, not a limit.
Can I see a model in 3D instead of a flat video?
On the Pro plan you can open 3D interactives, such as a DNA replication fork you can turn, step through and tap, with notes for each step.
Does Isotoon have AP Biology practice tests?
No. Isotoon explains ideas with short videos. For practice, use the released free-response questions and scoring guidelines the College Board publishes.
AP is a trademark registered by the College Board, which is not affiliated with, and does not endorse, Isotoon. Check the College Board’s course page for the current units and exam format.