Presented below is a photomicrograph showing a thin section of a corn kernel. This digital image was captured with the DXM 1200 ACT-1 control software in single-image acquisition mode utilizing fluorescence illumination.

Corn is the common name for the cereal grass widely grown as food for humans and animals. Along with wheat and rice, it is one of the world's chief grain crops and the largest crop grown in the USA. Native to the Americas, corn (Zea mays) is the domesticated variety of the Zea grass family, originally was cultivated by Native Americans 8,000 to 10,000 years ago.

Teosinte (Zea mexicana), a perennial wild corn thought to be extinct, still grows today in Mexico. Since its introduction into Europe in the 15th century, corn cultivation has spread to all areas of the world where it can be grown. In addition to providing food for human consumption, corn is also used as livestock feed. The inedible parts, such as the cob and husk, are used as raw material in industry.

There are many varieties of domestic corn, most of which were developed through aggressive breeding programs during the 20th century. The most important advance in corn cultivation came in 1933, with the introduction of hybrids. The thousands of hybrids that have been produced since then have increased corn yields and made it possible for the crops to flourish in almost any combination of soil and climate. Since the discovery of teosinte in 1978, new breeding programs have been underway to develop a perennial corn variety and hardier, pest resistant plants.