Solar cycle

src: www.nasa.gov The sun cycle or the solar magnetic activity cycle is an almost periodic 11-year change in solar activity (including ch...

Thylakoid

src: u18439936.onlinehome-server.com A thylakoid is a membrane-bound compartment in chloroplasts and cyanobacteria. They are the sites of ...

Passenger pigeon

src: upload.wikimedia.org The pigeon passengers or wild pigeons ( Ectopistes migratorius ) are endemic endangered pigeon species in Nor...