Physical Structure of Corn

In the heat of the summer, nurtured by its sisters and fed by the heat and light of the sun, corn grows tall and straight. Like our ancestors, we wait anxiously to pick it cook it and enjoy its sweet taste.

Because corn is one of the world's food staples, botanists, archaeologists, and anthropologists have spent a long time studying its origins and structures.

Theories to explain the origin of corn were debated throughout the 20th century. In the early 1900s, Nobel Prize winners George W. Beadle and Rollins A. Emerson documented the chromosomal (strand of DNA that carries genetic information) and genetic similarities between corn and teosinte. They concluded that teosinte was corn's ancestor.

The corn that we grow today is the result of crossbreeding of unrelated plant species through a process known as hybridization. The seeds from the most successful of these hybrid plants are kept and resown. Years of careful seed selection, along with back-crossing with parental plants, ultimately results in a new variety of plant. Many plants today are developed through hybridization under carefully controlled conditions in universities, experimental farms and laboratories. Our ancestors developed many of the varieties of corn we have today through a similar process on the land.

The corn we grow today is very familiar to us - but do you know all the parts of a corn plant? Do you know that there are male corn plants and female corn plants?

Main Parts of a corn plant:
Tassel:	The flower located at the top of the plant (male).
Silk:	The long, stringy threads sticking covering an ear of corn (female).
Kernels:	The seeds of the plant. This is the part of the plant that we eat.
Ear:	The entire part of corn we eat before preparation. An ear of corn is tightly wrapped in leaves for protection and looks like a giant roll of leaves. Rows upon rows of kernels are hidden away inside the husk of green leaves.
Stalk:	The plant part which grows straight up towards the sun. The broad flat leaves and flowers grow from the stalk.
Roots:	The plant part which grow down into the soil in search of water. Water is carried up from the soil to the leaves through the plant's roots, tubes, and veins.

Parts of the Kernel:
Pericarp:	the hard covering.
Endosperm:	provides food; starchy part.
Germ:	embryo; live part.
Tip Cap:	attaches to cob.

To learn more about the basic structure of the corn plant and quiz your own self-knowledge, visit this site (www.kycorn.org/thecornyfacts/kernel.html).