An adaptive assignment for intro biology: cellular respiration

November 6, 2026 · 7 min read

Five short-answer questions on cellular respiration, with answer keys, half-right student answers and the follow-up questions an adaptive assignment asks. Try the first one as a student, then use the set in your course.

This is a complete adaptive assignment for one week of an intro biology course: five short-answer questions on cellular respiration. Each question tests a few ideas, and each answer key lists them. When a student's answer is half right, they get a follow-up question on the half they missed.

You can try the first question as a student, read all five with their answer keys, and use the set in your own course.

Try question 1 as a student

Pick an answer a student might give. You see the grade, the ideas the answer covered and missed, and the follow-up it gets.

Intro Biology · Cellular respirationQuestion 1 of 5

During cellular respiration, what does oxygen do, and what happens to the cell when oxygen runs out?

Pick an answer to turn in

An example. These grades and follow-ups are written in advance to show how it works. In your course, AI grades each answer against your answer key and writes each follow-up.

The five questions

For each question: the answer key, a half-right answer, and a follow-up it could get. The answers and follow-ups are examples we wrote for this post. In your course, AI writes each follow-up for the student who needs it, from your question, its answer key and the ideas the answer missed. It never reads the student's own words to write it.

1. During cellular respiration, what does oxygen do, and what happens to the cell when oxygen runs out?

Answer key: Oxygen is the final electron acceptor of the electron transport chain.
Without oxygen, the chain stops and ATP output drops sharply.
The cell switches to fermentation to keep making a little ATP.
A half-right answer: "Oxygen is the final electron acceptor in the electron transport chain."
A follow-up it could get: A muscle cell runs low on oxygen during a sprint. What happens to its electron transport chain, and how does the cell keep making some ATP?

2. Where does most of the ATP from one glucose molecule come from, and why there?

Answer key: Most ATP comes from oxidative phosphorylation, not glycolysis or the Krebs cycle.
The electron transport chain pumps protons and builds a gradient across the inner mitochondrial membrane.
ATP synthase uses the protons' flow back across the membrane to make ATP.
A half-right answer: "Most of the ATP comes from the electron transport chain."
A follow-up it could get: The electron transport chain doesn't make ATP itself. What does it build across the inner mitochondrial membrane, and what uses that to make ATP?

3. What do NADH and FADH₂ do in cellular respiration?

Answer key: They carry high-energy electrons from glycolysis and the Krebs cycle.
They hand those electrons to the electron transport chain.
Handing them over turns them back into NAD⁺ and FAD, which the earlier steps need to keep running.
A half-right answer: "They're electron carriers made in the Krebs cycle."
A follow-up it could get: Where do NADH and FADH₂ take their electrons, and why does glycolysis slow down if they can't unload them?

4. Why does fermentation let a cell keep making ATP without oxygen, and why is it so much less efficient?

Answer key: Fermentation turns NADH back into NAD⁺, so glycolysis can keep going.
Glycolysis alone makes only 2 ATP per glucose.
Most of glucose's energy stays in the product, such as lactate or ethanol.
A half-right answer: "Fermentation lets glycolysis keep going, but it only makes 2 ATP."
A follow-up it could get: Glycolysis needs NAD⁺ to keep running. How does fermentation supply it, and where does the rest of glucose's energy end up?

5. Cyanide blocks the last protein complex of the electron transport chain. Why does a poisoned cell run out of ATP, even with plenty of oxygen and glucose?

Answer key: Electrons can no longer pass to oxygen, so the whole chain stops.
With no proton pumping, the gradient runs down and ATP synthase stops making ATP.
Only glycolysis still makes ATP, far too little to keep the cell alive.
A half-right answer: "Cyanide stops the electron transport chain, so no ATP gets made."
A follow-up it could get: With the chain stopped, what happens to the proton gradient and to ATP synthase? And does the cell make any ATP at all?

Why these questions work for follow-ups

Each question asks for a mechanism, not a term, and each answer key splits it into a few ideas a grader can check one by one. A student who writes only the first idea, which is the most common half-right answer, gets a follow-up on the other two. A student who names the right term but not the reason gets asked for the reason.

Question 5 also checks transfer: a student who learned the steps in order has to reason about what breaks when one step stops.

What you see as the instructor

Say a student answers question 1 with only the first idea, and scores 40. At the end of the assignment, they get the follow-up, and their answer covers most of what they missed: it scores 90. The follow-up earns 90% of the 60 points the first answer missed, so the question's score becomes 94. Their response shows both answers, under the question, with the follow-up's own answer key. You can change any grade.

Settings we would use

Adaptive quiz, at the end: students finish your five questions first, then answer their follow-ups.
One follow-up per question: enough for one week's homework. Raise the limit for a review before an exam.
Fast grading: the default, and enough for answers like these. Choose Smart grading when answers need more careful judging.
Show the score and the feedback after each answer, so a student knows why a follow-up came.

Use it in your course

Copy the five questions and their answer keys, and paste them into the quiz builder's assistant: ask it to make them a quiz with these correct answers. Change any question to match your lecture, turn on Adaptive quiz, and assign it with a due date. Our step-by-step guide walks through each step, and our SmartBook comparison shows how this differs from a SmartBook assignment.