Human Body
How Does DNA Store Genetic Information?
Learn how four chemical bases encode biological instructions, how cells copy DNA, and why genes are only part of the genome. Learn the key ideas, examples.
Human Body
Explore sleep, memory, the heart, vision, and human biology. Start with any question below, then follow the related links to learn the topic as a connected cluster.
Human Body
How Does the Digestive System Work? Step by Step
Follow food through the mouth, stomach, intestines, liver, pancreas, and gut to see how digestion releases nutrients and energy. Learn the key ideas.
Human Body
Why Do We Dream? What Science Knows So Far
Explore when dreams occur, how the brain creates them, and which theories about memory, emotion, and simulation have evidence. Learn the key ideas.
Human Body
How Does the Eye See Colors?
Retinal cone cells respond to overlapping wavelength ranges and the brain compares their signals to construct color perception in context. Learn the key.
Human Body
Why Does Our Heart Keep Beating?
Pacemaker cells in the sinoatrial node spontaneously produce electrical impulses that coordinate heart-muscle contractions and blood flow. Learn the key.
Human Body
How Does the Human Brain Store Memories?
Memory is distributed across neural networks; changing connections encode information while the hippocampus helps organize many new declarative.
Human Body
Why Do Humans Need Sleep? What Sleep Does for the Brain and Body
Sleep supports memory, learning, immune regulation, metabolism, emotional control, and tissue maintenance through repeating non-REM and REM.