Develop and use a model to illustrate the hierarchical organization of interacting systems that provide specific functions within multicellular organisms.

  1. Plants

    Before eating, Venus flytraps must ‘count’

    Researchers find that Venus flytraps respond to the number of times insects touch their sensory hairs. This tells them when it’s time to turn on digestion.

  2. Life

    Cell recount: People host far fewer germs

    Since the 1970s, microbiologists have been saying bacteria outnumber human cells in our bodies by about 10-to-1. A new analysis says that old number was a “fake” fact — and gross exaggeration.

  3. Health & Medicine

    Explainer: What is skin?

    The body’s soft, outer armor contains three layers, each with its own important role to play.

  4. Fossils

    Predatory dinos were truly big-mouths

    Large meat-eating dinosaurs could open their mouths wide to grab big prey. Vegetarians would have had a more limited gape, a new study suggests.

  5. Life

    Scientists discover itch-busting cells

    A study in mice finds the body has a special way of dealing with an itch that’s caused by a light touch. The results could lead to treatments for chronic itch.

  6. Chemistry

    Some air pollutants seep through skin

    The skin is the body’s largest organ. And it can let in as much or more of certain air pollutants than enter through the lungs, a new study finds.

  7. Tech

    New light on brain science

    A combination of physics, biology and engineering lets scientists use light to trigger actions by specific brain cells. Called optogenetics, this technology is shining new light on how the brain works.

  8. Health & Medicine

    These bubbles treat wounds

    New research shows bubble-powered drugs can travel upstream, against the flow of blood, to seal wounds shut.

  9. Animals

    Hummingbird tongues may be tiny pumps

    Scientists had thought that hummingbird tongues work through capillary action. A new study, though, concludes they work like little pumps.

  10. Health & Medicine

    New treatments may rally ex-president’s fight against cancer

    Former President Jimmy Carter has a potentially lethal type of skin cancer that has already spread to his liver and brain. Recent improvements in medicine may help him fight it.

  11. Health & Medicine

    Explainer: The nico-teen brain

    Both e-cigarettes and tobacco products can release large amounts of nicotine during use. Nicotine is the chemical that makes tobacco addictive — and the teen brain is especially vulnerable to it.

  12. Animals

    Picture This: The real ‘early bird’

    Long before dinosaurs went extinct, birds were emerging on Earth. These hummingbird-size wading birds are the earliest known ancestors of today’s birds.