How to study biology, chemistry and physics: three subjects, three methods

Biology, chemistry and physics reward different methods. Biology is vocabulary plus mechanism: learn the terms with flashcards, then redraw each process from memory until the arrows are right. Chemistry is procedures: study one worked problem, redo it cold, then do a sibling with new numbers. Physics is models: derive each equation once from the ones you know, so on the test you pick the right one instead of guessing. Below, each method with a worked example from a Grade 12 course.

Why one study method does not fit all three

Look at what each test asks. A biology test asks you to name, explain and connect: what this enzyme does, where glycolysis happens, why the membrane behaves as it does. A chemistry test asks you to compute and justify: a pH, an enthalpy, a rate, each with a set-up you have to get right before the numbers mean anything. A physics test asks you to model first and compute second: decide whether this is a forces problem or an energy problem, then pick the equation.

Three demands, so three methods. They share a core: answer first (test yourself before you reread), space it (come back on later days), and mix the question types in the last week. The subject-specific layer sits on top of that core. Studying biology like physics, or physics like biology, is the usual reason a hard-working science student gets a mark that does not match the hours.

How to study biology: vocabulary first, then the mechanism

Biology is two things stacked. Underneath is a vocabulary of hundreds of terms. Above it are mechanisms: pathways, cycles, feedback loops, structures. You cannot learn a mechanism while you are still looking up the words in it. So study in two passes.

Pass 1: the terms as flashcards

One idea per card. Write the front as a question, not a keyword, so you have to retrieve the answer rather than recognize it: "Where in the cell does glycolysis happen?" rather than "glycolysis". How to write flashcards that teach has the rules. Then space the cards: a few minutes a day across the week, not an hour the night before. Spacing the cards explains why the gaps do the work. Whether you searched for how to study bio, how to learn biology or how to study anatomy, pass 1 is the same, and it is the one part flashcard apps are built for.

Pass 2: the mechanism, by redrawing

Then close the book and draw the pathway from a blank page: boxes, arrows, labels, what goes in and what comes out. Compare it with the textbook's diagram. Fix it. Redraw it tomorrow. This is retrieval, and it beats studying with the book open. In a controlled study with undergraduates reading science texts, students who practised retrieving the material did better on a test a week later than students who spent the same time building a concept map with the text in front of them (Karpicke & Blunt 2011). Concept maps do help: a meta-analysis found that learning with concept and knowledge maps beat learning from text or lists (Nesbit & Adesope 2006). The two studies together say what to do. Draw the map, and draw it from memory.

For anatomy, the redraw is labelling from blank: an unlabelled diagram, every name written in from memory, checked, repeated on a later day. Group the structures by what they do rather than by where they sit in a list, so each name attaches to a mechanism and not to a position on a page.

Worked example: glycolysis, both passes

Glycolysis is the eighth idea on the SBI4U course map.

Pass 1, four cards:

Front	Back
Where does glycolysis happen?	In the cytoplasm.
What is the net ATP per glucose from glycolysis?	2.
What is reduced in glycolysis, and how many per glucose?	NAD+ to NADH; two per glucose.
What is the end product, per glucose?	Two pyruvate, three carbons each.

Pass 2, the redraw in one line of arrows: invest 2 ATP → split the six-carbon sugar into two three-carbon pieces → harvest 4 ATP and 2 NADH → net 2 ATP, 2 NADH, 2 pyruvate. The arithmetic you can check: 4 ATP made minus 2 ATP spent is a net of 2. Draw it until the arrows are right without looking.

How to study chemistry: procedures, learned by redoing

Most chemistry marks are calculations with a set-up: a pH, a solubility product, an enthalpy, a limiting reagent. That is a procedure, and the way to learn a procedure is the worked-example cycle: read one example line by line, close it, redo it from a blank page, do a sibling with new numbers, and keep an error log naming the exact wrong line. Worked examples beat unaided problem solving for a new procedure (Sweller & Cooper 1985), and removing the steps one at a time from the end of an example is the bridge from example to problem (Renkl & Atkinson 2003).

Not all of chemistry is procedure. The naming chapters, the functional groups, VSEPR shapes and intermolecular forces are vocabulary. Treat those like biology: cards, spaced. If you understand the examples and cannot start a problem, that is the sign you have been reading examples and not redoing them, and the fix is the cycle, not more chemistry help.

Worked example: the pH of a strong acid

The idea is the nineteenth on the SCH4U course map.

The example: find the pH of 0.0050 mol/L HCl.

1. HCl is a strong acid, so it ionizes completely: [H+] = 0.0050 mol/L.
2. pH = −log[H+] = −log(0.0050).
3. log(0.0050) = log(5) + log(10^−3) = 0.699 − 3 = −2.301.
4. pH = 2.30.

Redo it cold. Then the sibling: 0.025 mol/L HCl. [H+] = 0.025; log(0.025) = log(2.5) − 2 = 0.398 − 2 = −1.602; pH = 1.60. Check it against sense: a more concentrated acid should have a lower pH, and 1.60 is lower than 2.30.

The common wrong line: treating HCl as a weak acid and setting up a Ka table, as if only a fraction of the molecules had ionized. The rule it broke: a strong acid ionizes completely, so [H+] equals the concentration you were given. Log that in those words and redo it in two days. In chemistry, the set-up line is where the marks go, and the set-up line is what the redo trains.

How to study physics: derive before you memorize

The formula sheet is not the problem in physics. Choosing is. A student who has memorized twelve equations as strings of symbols has twelve things that look alike on a test and no way to pick between them. A student who has derived each one from the two or three they already know carries the model, and the model picks the equation.

So derive each equation once, with a pen, from the ones you know. Say in words what each symbol means as you go. Generating the material yourself, by deriving, drawing or explaining, produces better learning than receiving it finished (Fiorella & Mayer 2016), and students prompted to explain each line to themselves while reading a science text understood it better than students who read the text twice (Chi et al. 1994).

Worked example: a projectile, built from two equations

Projectile motion is the first idea on the SPH4U course map. Start from the two equations you know: v = v0 + at, and Δd = v0·t + ½at^2.

A ball rolls off a 20 m cliff at 15 m/s horizontally. How far from the base does it land?

1. Vertical: the ball starts with no vertical speed, so Δd = ½at^2 with a = 9.8 m/s^2. That gives 20 = ½(9.8)t^2 = 4.9t^2.
2. t^2 = 20 / 4.9 = 4.08, so t = 2.02 s.
3. Horizontal: there is no horizontal acceleration, so Δx = v·t = 15 × 2.02 = 30.3 m.

Check: 4.9 × 4.08 = 19.99, which is 20 to the rounding used. And 15 × 2.02 = 30.30.

Now the derivation that stops you memorizing a third equation wrong. From v = v0 + at, t = (v − v0) / a. Put that t into Δd = v0·t + ½at^2 and simplify. The result is Δd = (v^2 − v0^2) / (2a), which rearranges to v^2 = v0^2 + 2aΔd. You have just built the equation most students memorize with the wrong sign. Having built it once, you also know it has no t in it, which tells you when to reach for it: when time is neither given nor asked for. On the test, name the model (kinematics, forces, energy, momentum) before you touch a formula.

What all three share: the error log and the mixed set

Three things carry across the subjects.

The four-column error log from the maths page: date, problem, the exact wrong line copied as you wrote it, the rule it broke in your words. In biology the "wrong line" is the arrow that pointed the wrong way or the label on the wrong structure. In physics it is usually the first line, the model you chose.

The mixed set in the last week: problem types shuffled so you have to choose the method, which is what the test does. Mixed practice feels harder and tests better (Rohrer & Taylor 2007). Mixing problem types has the method and the evidence.

And redrawing or recomputing from a blank page instead of rereading. Chapter 1 of the free playbook is that rule, answer first, in full.

The week before a science test

Subject	Days 7 to 3, each session	Day 2	Day 1
Biology	Cards daily; one pathway or structure redrawn from blank	A timed run of past questions, marked, errors logged	Redraw the logged pathways; a last pass of cards; sleep
Chemistry	One worked-example cycle (read, redo cold, sibling); naming cards	A timed mixed set of every calculation type in the unit	Redo the error log cold; sleep
Physics	One derivation plus three mixed problems	A timed mixed set, the model named first on every problem	Redo the error log cold; sleep

The day-by-day test plan fills in the hours for any subject. Day 1 is light on purpose: the night's sleep is part of the plan, not time off it.

Summary

• Biology: terms as question-cards, spaced; then redraw every mechanism from a blank page until the arrows are right.
• Chemistry: one worked problem, redone cold, then a sibling; the naming chapters as cards; an error log that names the line.
• Physics: derive each equation once from the ones you know; name the model before the formula; mixed sets in the last week.