Lung lining. Color-enhanced scanning electron micrograph (SEM) of a section through epithelial cells of the terminal bronchus (lung airway). Some of the cells are covered in cilia, tiny microscopic hairs. Rhythmic movements of the cilia serve to move mucus and trapped particles away from the gas-exchanging parts of the lung, and towards the throat, where they can be expelled. Magnification: x10,000 when printed at 10 cm wide.
animated! nothing-without-science: Metamorphosis is a biological process by which an animal physically develops after birth or hatching, involving a conspicuous and relatively abrupt change in the animal’s body structure through cell growth and differentiation. Some insects, amphibians, molluscs, crustaceans, Cnidarians, echinoderms and tunicates undergo metamorphosis, which is usually accompanied by a change of habitat or behavior.