The Solar System, Explained
A friendly tour of the planets, moons and the star at the middle of it all.
Which planet is closest to the Sun?
You are using it to read this sentence. Ten questions on the organ that does your thinking, remembering and dreaming — each with the reason behind the answer.
Three pounds of tissue, tens of billions of neurons, and the most complex object we know of, sitting inside your own skull. This quiz explores the human brain: how it is organized, what its different regions do, and the surprising facts about memory, perception, and how thinking actually works. The questions favour real understanding over neuroscience jargon, and every answer comes with a short explanation. It pairs neatly with the way QuizKite itself is built, since the same brain you are reading about is the one quietly filing away each fact as you play.
Every question in this quiz is listed below with its correct answer and the reasoning behind it. Play first if you would rather not see the answers — or read through as a study sheet.
Play it insteadAnswer: A. The cerebrum
Why: The cerebrum is by far the largest part, split into two hemispheres. It handles thinking, the senses and all voluntary action.
Answer: D. About 86 billion
Why: The adult brain holds an estimated 86 billion neurons. Each one can form thousands of connections with its neighbours.
Answer: B. The right side
Why: The brain's wiring crosses over at the base, so the left hemisphere controls the right side of the body, and the right hemisphere the left.
Answer: C. Myelin
Why: Myelin wraps around the long axons of neurons like the insulation on a wire, letting electrical signals travel far faster.
Answer: A. The hippocampus
Why: The hippocampus helps turn short-term experiences into lasting memories. Damage to it can leave someone unable to form new ones.
Answer: D. About 20%
Why: The brain is remarkably hungry, consuming around 20% of the body's energy even at rest — far more than its size suggests.
Answer: D. Synapses
Why: At a synapse, one neuron releases neurotransmitters that drift across a microscopic gap to signal the next neuron.
Answer: B. The corpus callosum
Why: The corpus callosum is a dense bundle of some 200 million nerve fibres, letting the two hemispheres share information constantly.
Answer: B. The brainstem
Why: The brainstem quietly runs the essentials — breathing, heart rate and blood pressure — without any conscious effort on your part.
Answer: C. Cerebral cortex
Why: The folded cerebral cortex greatly increases surface area, packing far more processing power into the limited space of the skull.
Answer: B. The thalamus
Why: The thalamus sits near the centre of the brain and passes almost all incoming sensory information on to the cortex for processing.
The Human Brain has 11 questions and takes about 8 minutes to finish. It is rated Medium and sits in our Science & Nature category.
Each of the 11 correct answers adds 10 XP, up to 110 XP for a clean run. Wrong answers cost you nothing, and your full question-by-question review is shown at the end.
Yes. All 11 questions carry a written explanation of why the correct answer is right, so the quiz works as a study sheet as well as a test.
Yes, as often as you like. The questions and the answer options are reshuffled on each run, and you can use Practice Mistakes afterwards to retry only the ones you missed. No account is needed to play.
Every quiz on QuizKite is researched, written and fact-checked by hand against reliable references, with an explanation for each answer. Read our full Editorial Policy to learn more about our content standards.
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Which planet is closest to the Sun?
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What is the largest organ of the human body?
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What is the chemical symbol for gold?
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In which layer of the atmosphere does nearly all weather occur?
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